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397 Cards in this Set

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collateral circulation in the case of a blocked abdominal aorta
Internal thoracic artery - continuous with the superior epigastric artery, which anastomoses with the inferior epigastric artery (a branch of the external iliac artery). This may provide a route of collateral circulation if the abdominal aorta is blocked (e.g a postductal coarcation of the aorta).
branches of the subclavian artery
1) internal thoracic
2) vertebral
3) thyrocervical
a. suprascapular
b. transverse cervical
c. inferior thyroid
branches of the axillary artery
1st part: superior thoracic

2nd part: thoracoacromial, lateral thoracic

3rd part: anterior/posterior humeral circumflex, subscapular (which gives off the thoracodorsal, circumflex scapular arteries)
Damage to deep brachial artery

*the deep brachial artery ends by dividing into the middle collateral artery and radial collateral artery
a fracture of the humerus at midshaft can injure the deep brachial artery and/or the radial nerve as they travel together in the radial groove on the posterior aspect of the humerus.
collateral circulation around the shoulder
thyrocervical->transverse cervical->circumflex scapular-> subscapular -> axillary

thyrocervical->suprascapular-> circumflexscapular-> subscapular->axillary
collateral circulation around the elbow
a) superior ulnar collateral --> posterior ulnar recurrent artery
b) inferior ulnar collateral --> anterior ulnar recurrent artery
c) middle collateral artery --> recurrent interosseous
d) radial collateral artery --> recurrent radial artery
collateral circulation in the hand
superficial palmar arch (mostly supplied by the ulnar artery) --> deep palmar arch (mostly supplied by the radial artery)
Subclavian steal syndrome
retrograde flow in the vertebral artery resulting from ipsilateral subclavian artery stenosis.

more common on the left side due to accelerated atherosclerosis.

signs: syncope, neurologic deficits (esp. on exercise), blood pressure differential between the arms
placement of ligatures in the shoulder/arm
a surgical ligature may be placed on the subclavian artery or axillary artery between the thyrocervical trunk and subscapular artery. A surgical ligature may also be placed on the brachial artery *distal* to the inferior ulnar collateral artery.

a ligature may NOT be placed on the axillary artery between the subscapular artery and the deep brachial artery!!
percutaneous arterial catheterization uses the brachial artery (if the femoral artery approach is unavailable).
the left brachial artery is preferred because approaching from the left side allows access to the descending aorta without crossing the right brachiocephalic trunk and left common carotid arteries, reducing the risk of stroke.
Allen test
this is a test for occlusion of either the radial or ulnar arteries. blood is forced out of the hand by making a fist, and then one of the 2 arteries is compressed. If blood fails to return to the fingers after the fist is opened, then the uncompromised artery is occluded
laceration of the palmar arches
results in profuse bleeding. because of the collateral circulation, you can't just ligate either the ulnar or radial artery. you may need to compress the brachial artery proximal to the elbow
Raynaud syndrome
idiopathic condition, characterized by intermittent bilateral ischemia of the fingers.

a cervicodorsal presynaptic sympathectomy may be performed to dilate the digital arteries.
cutaneous nerves of the upper limb (1)
supraclavicular nerve: arises from the cervical plexus (C3-4), innervates skin over the upper pectoral, deltoid, and outer trapezius areas
Median brachial/antebrachial cutaneous nerve: arises from the medial cord of the brachial plexus
lateral brachial cutaneous nerve: arises from the axillary nerve
lateral antebrachial cutaneous: arises from the musculocutaneous
cutaneous nerves of the upper limb (2)
posterior brachial/antebrachial cuntaneous nerves: arise from radial n.
median nerve: innervates skin of lateral palm & palmar /digital dorsal aspects of lateral 3.5 digits
ulnar nerve: skin of 1/2 ring finger, little finger, & surrounding skin of hand
radial nerve: skin of lateral dorsum of hand, and proximal dorsal aspects of lateral 3.5 digits
major terminal branches of the brachial plexus
**don't forget how to diagram the plexus!

musculocutaneous (C5-7), axillary (C5/6), radial (C5-T1), median (C5-T1), ulnar (C8-T1)
Erb-Duchenne palsy

injury to the upper trunk of the brachial plexus by a violent stretch between the head and shoulder.
damage is to the musculocutaneous (biceps), suprascapular (infraspinatus), axillary (teres minor, deltoid) and phrenic (diaphragm)

clinical signs - arm pronated and medially rotated ("waiter's tip hand"), ipsilateral diaphragm paralysis
Klumpke palsy

injury to the lower trunk of the brachial plexus (C8 and T1 ventral primary rami)
caused by a sudden pull upward of the arm, damage is to the median nerve, ulnar nerve, and sympathetics of the T1 spinal nerve

loss of wrist/hand function, and Horner's syndrome
long thoracic nerve injury
caused by a stab wound or removal of lymph nodes during a mastectomy. paralysis of the serratus anterior muscle occurs, resulting in *winging of the scapula*

the serratus anterior is tested clinically by having the patient push against a wall with both hands
axillary nerve injury
caused by fracture of the surgical neck of the humerus or *anterior* dislocation of the shoulder joint. sensory loss over the lateral upper arm, paralysis of the deltoid and teres minor occurs.
radial nerve injury

*remember "Dr. Cuma"
"wrist drop" occurs (paralysis of wrist extensors), as well as sensory loss over the posterior arm/forearm and lateral dorsum of hand.

may be caused by fracture of the humerus at mid-shaft, a badly fitted crutch, or falling asleep with the arm over a chair.
medial nerve injury at the elbow or axilla
may be caused by a supracondylar fracture of the humerus

paralysis of flexor muscles in the forearm, as well as "ape hand" or "benediction hand" - opposition, abduction, and flexion of the thumb is lost with a flattening of the thenar eminence
medial nerve injury at the wrist
may be caused by slashing the wrists in a suicide attempt or by carpal tunnel syndrome. the presentation looks like medial nerve injury at the elbow, except that the wrist flexors are fine, and flexion of the thumb remains

test: make O with thumb and index
Ulnar nerve injury at the elbow or axilla
may be caused by a fracture of the medial epicondyle of the humerus.

clinically, a mild "clawhand" is observed
ulnar nerve injury at the wrist
may be caused by a slashing of the wrist in a suicide attempt.

clinically a severe "clawhand" is observed because of the unopposed action of the flexor digitorum profundus

test: hold paper between middle and ring finger
quadrangular space
transmits the axillary nerve and posterior humeral circumflex artery

bounded superiorly by teres minor and subscapularis muscles, inferiorly by teres major, medially by the long head of the triceps, and laterally by the surgical neck of humerus
upper triangular space
transmits the circumflex scapular artery

between the teres major muscle, teres minor muscle, and lateral head of triceps

** the long head of the triceps separates the triangular space from the quadrangular space
lower triangular space
transmits the radial nerve and deep brachial artery

between the teres major, long head of triceps, and medial head of triceps
glenohumeral joint
2 prominent bursae: the subacromial bursa (separates the tendon of the supraspinatus muscle from the deltoid), the subscapular bursa (separates the scapular fossa and the tendon of the subscapularis)
anterior shoulder dislocation
anterior/inferior dislocation of the humerus resulting in a palpable head of the humerus the axilla. commonly caused by a blow to the tip of the shoulder

may damage the axillary nerve or artery
Hill-Sachs lesion following shoulder dislocation
impaction of the anterior-inferior surface of the glenoid labrum on the posterolateral aspect of the humeral head after it dislocates may cause a depressed humeral head fracture called a Hill-Sachs lesion
Rotator cuff injury
aka subacromial bursitis or painful arc syndrome. usually either tendinitis or isolated tear of the supraspinatus tendon and the subacromial bursa.
Acromioclavicular joint
stabilized by the coracoacromial ligament, coracoclavicular ligament, and the acromioclavicular ligament
Shoulder separation
(acromioclavicular subluxation)

clinical signs: injured arm hangs lower than normal, noticeable bulge at tip of shoulder b/c of upward displacement of clavicle, and pushing down on the lateral end of the clavicule and release causes a rebound (piano key sign)
common injury caused by a downward blow at the tip of the shoulder. 3 grades:
grade I: no ligament tearing, no abnormal joint spaces (sprain)
grade II: torn acromioclavicular ligament, larger acromioclavicular space
grade III: coracoclavicular ligament and acromioclavicular ligaments are torn, and both the coracoclavicular and acromioclavicular spaces are larger
clavicle fracture

*the subclavian artery/vein/brachial plexus may be put in danger by a clavicle fracture
most commonly occurs in the middle

upward displacement of the proximal fragment (pull of sternocleomastoid), downward displacement of distal fragment (pull of deltoid muscle and gravity
elbow joint
3 articulations: humeroulnar (ulnar collateral ligament), humeroradial (radial collateral ligament), radioulnar (annular ligament)
tears in the elbow joint
tear of ulnar collateral ligament allows abnormal abduction of forearm

tear of radial collateral ligament allows abnormal adduction
Nursemaid's elbow

clinical signs: child presents with a flexed and pronated forearm held close to the body
severe distal traction of the radius (e.g. a parent yanking the arm of a child) can cause subluxation of the head of the radius from its encirclement by the annular ligament.

reduction involves applying direct pressure posteriorly on the head of the radius while supinating and extending the forearm
Lateral epicondylitis (tennis elbow)
inflammation of the common extensor tendon where it originates on the lateral epicondyle of the humerus
medial epicondylitis (golfer's elbow)
inflammation of the common flexor tendon of the wrist where it originates on the medial epicondyle of the humerus
Tommy John surgery
replaces or augments a torn ulnar collateral ligament (classically injured in baseball pitchers)
Supracondylar fracture of the humerus
places contents of cubital fossa in jeopardy (specifically the median nerve)
little leaguer's elbow
avulsion of the medial epicondyle by violent or multiple contractions of the flexor forearm muscles
dislocation of the elbow
most commonly a posterior dislocation of the radius and ulna with respect to the distal end of the humerus
fracture of the olecranon
may result from a fall on the forearm with the elbow flexed (transverse) or a fall directly on the olecranon process itself (comminuted - broken into a bunch of pieces)
carpal tunnel syndrome
compression of the median nerve within the carpal tunnel. the flexor retinaculum covers the flexor digitorum superficialis/profundus tendons, flexor pollicis longus tendon, and median nerve. No arteries pass through the carpal tunnel. sensory loss, ape hand, flattening of thenar eminence occurs
slashing of the wrists
on the radial side: radial artery, median nerve, flexor carpi radialis, palmaris longus tendon

on the ulnar side: ulnar artery, ulnar nerve, flexor carpi ulnaris tendon
Dupuytren contracture
a thickening and contracture of the palmar aponeurosis, highly correlated with CAD

results in progressive flexion of fingers (worst in ring, little finger)
Volkmann ischemic contracture
contracture of the forearm muscles - commonly caused by a supracondylar fracture of the humerus in which the brachial artery goes into spasm, reducing blood flow.

can occur by an overly tight cast or compartment syndrome due to edema or hemorrhage
Colles' fracture
fracture of the distal portion of the radius in which the distal fragment is displaced posteriorly. This occurs when a person falls on an outstretched hand with the wrist extended. Also commonly accompanied by a fracture of the ulnar styloid process.

**in a colles fracture, the cast has to go all the way up to mid-arm because the brachioradialis binds at the broken portion of the distal radius!
Gamekeeper's thumb
disruption of the ulnar collateral ligament of the MP joint of the thumb. often associated with an avulsion fracture at the base of the proximal phalanx of the thumb.

occurs in skiing falls, results in weakened ability to hold objects, decreased thumb stability
Boxer's fractures
fracture of the head of the 5th metacarpal
thoracic outlet syndrome
compression of the neurovascular structures at the superior aperture of the thorax (brachial plexus, subclavian artery/vein)

3 major causes: anatomic (scalene triangle, cervical rib), trauma, and neurovascular entrapment at the costoclavicular space.

cervical ribs are found in the majority of arterial cases.
branches of the internal iliac artery
iliolumbar artery, lateral sacral artery, superior gluteal artery, inferior gluteal artery, middle rectal artery, uterine artery, obturator artery, inferior vesical artery, superior vesical artery, obliterated umbilical artery, internal pudendal
obturator artery

**of considerable importance in children, because it supplies the head of the femur proximal to the growth plate. of little importance to the femoral head in adulthood
continuation of the internal iliac artery, passing through the obturator foramen and giving off: muscular branches to the adductor muscles, artery to the head of the femur
Acute arterial occlusion in the leg
most commonly caused by an embolism or thrombosis where the femoral artery gives off the deep femoral artery. pain, paralysis, paresthesia, pallor, poikiloderma, pulselessness (the 6 Ps). You'll lose the lower limb in 4-8 hrs.
most common condition affecting the lumbosacral plexus
herniation of intervertebral disks!
superior/middle/inferior clunial nerves
arise from lumbar, sacral plexus (L1-L3, S1-S3) and gluteal branches of the posterior femoral cutaneous nerves.
1) genitofemoral nerve

2) iliohypogastric nerve
1) arises from the lumbar plexus (L1-2) and innervates the skin. Innervates the skin of the lateral femoral triangle

2) comes from the lumbar plexus (L1) - innervates skin over superolateral quadrant of buttock
1) lateral femoral cutaneous nerve

2) posterior femoral cutaneous nerve
1) comes from lumbar plexus (L2-3) - *not* the femoral nerve directly! innervates skin on anterior & lateral thigh

2) arises from sacral plexus (S1-S3), innervates skin of buttock, thigh, and calf
1) cutaneous branch of obturator nerve

2) cutaneous branch of femoral nerve

3) posterior cutaneous nerve of thigh
1) arises from the obturator nerve (L2-4) and innervates skin of middle part of medial thigh

2) arises from the femoral nerve (L2-4) and innervates skin of anterior and medial thigh

3) arises from sacral plexus (S1-3) innervates skin of posterior thigh and popliteal fossa
1) saphenous nerve

2) lateral/medial sural cutaneous nerve
1) arises from femoral nerve in femoral triangle and innervates skin of medial leg and foot (travels w/ saphenous v.)

2) arises from common fibular nerve (S1/2), innervates skin of back of leg and lateral side of ankle, foot, along with the medial (arising from the tibial nerve (S1/2)
1) superficial fibular nerve

2) deep fibular nerve
1) arises from common fibular nerve (L4-S1), innervates anterolateral leg and dorsum of foot

2) arises from common fibular (L5) and innervates web btw 1st and 2nd toe
1) medial plantar nerve

2) lateral plantar nerve
1) arises from tibial nerve (L4/L5) and innervates skin of medial sole of foot and medial 3 1/2 toes

2) arises from tibial nerve (S1/S2) and innervates the skin of the lateral sole of the foot and lateral 1 1/2 toes
6 major terminal branches of the lumbosacral plexus:

**the tibial nerve and common fibular nerve make up the sciatic nerve.
1) femoral nerve L2-4
2) obturator nerve L2-4
3) superior gluteal nerve L4-S1
4) inferior gluteal nerve L5-S2
5) common fibular nerve (L4-S2)
a. superficial fibular, b. deep fibular
6) tibial nerve
Femoral nerve injury
may be caused by trauma at the femoral angle or pelvic fracture.

paralysis of the iliacus and sartorius weakens flexion of the thigh

paralysis of the quadriceps femoris results in loss of the knee-jerk reflex

sensory loss occurs on the anterior thigh and medial leg
Obturator nerve injury
caused by anterior dislocation of the hip or a radical retropubic prostatectomy. Adduction is lost, as is sensation on the medial thigh
superior gluteal nerve injury
caused by surgery, posterior dislocation of the hip, or fracture of the neck of the femur.

paralysis of gluteus medius/minimus occurs such that abduction of the thigh is lost. The patient demonstrates a positive Trendelenburg sign.
inferior gluteal nerve injury
may be caused by surgery or posterior dislocation of the hip. paralysis of the gluteus maximus (main hip extensor) occurs such that the patient will be able to walk, but not climb stairs, jump, or stand from a seated position.

when walking, the patient will lean backward at heel strike to compensate for the loss of gluteus maximus function
common fibular nerve injury

**this is a very common type of injury!!
caused by a blow to the lateral aspect of the leg or fracture of the neck of the fibula.

paralysis of lateral compartment leg muscles --> loss of eversion, paralysis of anterior compartment --> loss of dorsiflexion and toe extension, sensory loss occurs on the anterolateral leg and dorsal foot.

pt. presents with foot drop and inverted - pt. can't stand on heels - also see foot slap and high gait
tibial nerve injury caused by trauma at the popliteal fossa
loss of plantarflexion, flexion of toes, sensory loss on sole of foot

pt. presents with foot dorsiflexed and everted - pt. cannot stand on toes.
ligaments supporting the hip joint
Illiofemoral ligament (Y ligament of Bigelow) - reinforces the hip joint anteriorly

Pubofemoral ligament - reinforces inferiorly

Ischiofemoral ligament - reinforces posteriorly

Ligamentum teres - minor role in stability, but carries the artery to the head of the femur.
femoral triangle
bounded by the inguinal ligament, sartorius muscle, and adductor longus. the floor is the pectineus and iliopsoas, the roof is the fascia lata. The triangle contains: femoral nerve, artery, vein, empty space, canal (NAVEL). **the nerve is NOT with the femoral sheath, and the canal is the location of femoral hernias
acetabular fractures
occur in high-energy car accidents or high falls. can be simple (one fracture) or complex (more than one fracture).
posterior dislocation of the hip
the hip is most commonly dislocated posteriorly resulting from severe trauma (ex. car accident when the flexed knee hits the dashboard). the lower limb is internally rotated, adducted, and shorter than the normal limb. Avascular necrosis of the femoral head may occur, and the sciatic nerve may be damaged.
Anterior dislocation of the hip joint
account for the remainder of hip dislocations. the lower limb is externally rotated and abducted. the femoral artery may be damaged so that the lower limb becomes cyanotic
femoral neck fracture
most commonly occurs in elderly women with osteoporosis just distal to the femoral head.

lower limb is externally rotated and shorter than the normal limb. avascular necrosis of the femoral head may occur if the medial and lateral circumflex arteries are compromised
Legg-Perthes disease
idiopathic avascular necrosis of the head of the femur, most commonly unilaterally in white boys who present with hip pain, slight external rotation, and a limp. 3 phases: initial phase, degenerative phase, and regenerative phase
ligamentous support of the knee
Patellar, medial (tibial) collateral ligament, lateral (fibular) collateral ligament, anterior cruciate ligament, posterior cruciate ligament
components of the popliteal fossa:
NVA: tibial/common fibular nerve, popliteal vein, popliteal artery and lesser saphenous vein (entering the popliteal vein)
1) medial collateral ligament (knee)

2) lateral collateral ligament (knee)
1) prevents abduction - recognized by abnormal passive abduction of the extended leg

2) prevent adduction - recognized by abnormal passive adduction of the extended leg
menisci of knee
medial meniscus - C-shaped fibrocartilage is attached to medial collateral ligament - easily torn.

lateral meniscus - O-shaped fibrocartilage. tears most commonly associated with anterior cruciate ligament tear.
"Terrible triad"

** the medial collateral ligament is continuous with the medial meniscus, but the lateral collateral ligament is NOT continuous with the lateral meniscus!
result of fixation of semiflexed leg receiving a violent blow on the lateral side (e.g. football "clipping") causing abduction and lateral rotation that damages: anterior cruciate ligament, medial meniscus, medial collateral ligament
ankle joint is supported by 2 ligaments:
medial (deltoid) ligament - actually consists of several ligaments, edtending from medial malleolus to the talus, navicular, calcaneus bones.

lateral ligament - also several ligaments, extends from lateral malleolus to talus and calcaneus.
relationship of structures to the medial malleolus: anteriorly and posteriorly
anterior: saphenous nerve/vein

posterior: tom, dick, harry, ANd fred
tibialis posterior, flexor digitorum longus, flexor hallucis longus, posterior tibial artery, tibial nerve,
transverse tarsal joint
articulation of talus/calcaneus with cuboid/navicular - where inversion and eversion occur
Inversion injury (most common ankle injury)
1) stretch or tear of lateral ligament, most commonly the anterior talofibular ligament
2) fracture of the fibula
3) avulsion of the tuberosity of the fifth metatarsal (called a *Jones Fracture*) where the fibularis brevis attaches
Eversion injury (Pott's fracture)
1) avulsion of the medial malleolus (the medial *deltoid* ligament is so strong that instead of tearing it avulses the medial malleolus
2) fracture of the fibula resulting from lateral movement of the talus
ski boot injury
usually results in fracture of the distal portions of the tibia and fibula
calcaneal fracture (Lover's fracture)
occurs when a person jumps from a great height. usually involves the subtalar joint, also associated with fractures of the lumbar vertebrae and neck of the femur
Lisfranc injury
occurs when bikers get their foot caught in the pedal clips or from a car wreck.

results in fracture or dislocation at the tarsometatarsal joint (Lisfranc joint)
Atlanto-occipital joints
articulation between the atlas (C1) and the occipital condyles.

the actions of nodding and sideways tilting of the head occurs here - these are synovial joints and have *no* intervertebral disks.

the anterior and posterior atlanto-occipital membranes limit excessive movement here.
Atlanto-axial joints
2 lateral atlanto-axial joints and one median atlanto-axial joint.

the action of saying "no" occurs here - they are synovial pivot joints.

the alar ligaments that extend from the sides of the dens to the lateral margins of the foramen magnum limit excessive movement here
Vertebral levels for reference:
Hyoid bone, bifurcation of common carotid artery (C4), Thyroid cartilage, carotid pulse (C5), Cricoid cartilage, start of trachea, start of esophagus (C6), sternal notch, arch of aorta (T2), sternal angle, sup/inf. mediastinum border, trachea bifurcation (T4), Pulmonary hilum (T5-7), inf. vena cava hiatus (T8), xiphisternal joint (T9)
esophageal hiatus (T10), aortic hiatus (T12), duodenum (T12-L1), Celiac artery, upper pole L kidney (T12), sup. mesenteric artery, upper pole R kidney, end spinal cord adult in adult - conus medularis (L1), Renal artery (L2) end spinal cord (newborn), inferior mesenteric artery, umbilicus (L3)
Iliac crest, bifurcation of aorta (L4)
sacral promontory, sig. colon (S1)
end dural sac (S2), end sig colon (S3)
atlanto-axial dislocation (subluxation)

widening of atlantodental interval suggests tearing of the transverse ligament
caused by rupture of the transverse ligament of atlas as a result of trauma (e.g. Jefferson fracture) or rheumatoid arthritis. This allows mobility of the dens, placing the spinal cord or medulla at risk.
dislocation without fracture (spinal cord)

vs. dislocation with fracture
1) only occurs in the cervical region because the articular surfaces are inclined horizontally. cervical dislocations will stretch the posterior longitudinal ligament

2) occurs in the thoracic/lumbar region
hemivertebrae
occurs when a portion of the vertebral body fails to develop and can lead to scoliosis
sickle cell anemia effects on vertebrae
"fish mouth vertebra" in which central depressions occur in the vertebral body
osteomyelitis
a bacterial infection that can occur within vertebral bodies. s. aureus and p. aeruginosa (in immunosuppressed patients and IV drug users) are causative, as is salmonella is sickle cell anemia patients
spondylolysis
stres fracture of the pars interarticularis (area btw pedicle and lamina) - often seen in adolescent athletes, mostly at L4-L5. On an oblique radiograph of the lumbar vertebrae, the fracture appears as a radioluscent "collar" around the neck of the scottie dog
spondylolisthesis

traumatic spondylolisthesis of C2 includes: fracture of the pars interarticularis bilateral to C2 vertebra, anterior subluxation of C2, tear of anterior longitudinal ligament, and posterior fractured portion of C2 remains attached to C3
spondylo = vertebra, listhesis = to slide on an incline

the anterior subluxation of the vertebral body so the body moves anterior with respect to the vertebrae beneath it, causing lordosis

can be congenital (L5/S1), degenerative (L4/L5), or traumatic (C2 spondylolisthesis = hangman's fracture - force is applied with hyperextended neck)
Spondylosis
very common degenerative process of the vertebral column that occurs in the *cervical* region of elderly patients.

disk space narrowing and bone spur formation
ankylosing spondylosis (rheumatoid spondylitis or Marie-Strumpell disease)
inflammatory osteoarthritis generally affecting the lumbar vertebrae and SI joint.

the annulus fibrosus of the intervertebral disks may become ossified, producing severe spinal immobility, forming a "bamboo spine". HLA-B27
Teardrop fracture
hyperflexion of cervical region
avulsion fracture of vertebral body
fracture of spinous process
compression of spinal cord
posterior subluxation of vertebrae
Jefferson fracture
compression of cervical region (e.g. force applied to top of head)

fracture of C1, lateral displacement of C1 beyond margin of C2 vertebra, and tear of transverse ligament.
Hyperextension (whiplash) injury of the cervical region
tear of anterior longitudinal ligament, widening of intervertebral space
chance fracture
hyperflexion of thoracic or lumbar reigon (seat-belt injury)

L2 or L3 usually, does not place spinal cord at risk. Transverse fracture of vertebral body, rupture of intervertebral disk, tear of ligaments
filum terminale

*conus medullaris is the end of the spinal cord - occurs at L1 in the adult and L3 in the newborn.
prolongation of the pia mater from the conus medullaris to the end of the dural sac at S2 where it blends with the dura. The dura continue caudally as the filum of the dura mater (or coccygeal ligament) which attaches to the dorsum of the coccyx bone.
arterial supply of spinal cord
1. anterior spinal artery (arises from vertebral arteries and runs in the anterior median fissue)
2. anterior and posterior medullary segmental arteries
3. great anterior segmental medullary (of adamkiewicz)
C2: top/posterior skull
V1 (opthalamic), V2 (maxillary), V3 (mandibular) - divisions of cranial n. V
C3: upper neck
C4: lower neck
C5: shoulder, lateral thumb
C6: thumb (6 shooters)
C7: posterior upper limb, index/middle finger
C8: ring/little finger
T1: medial surface of upper limb
T4: nipples
T7: xiphoid process
T10: umbilicus (appendix pain)
L1: inguinal ligament
L4: medial surface of leg, big toe
L5: lateral leg, dorsum of foot
S1: posterior lower limb, lateral foot, little toe
S2-S5: genitalia and anal zone
ribs
true ribs 1-7
false ribs 8-12
ribs 8-10 form the anterior costal margin, ribs 11 and 12 are floating ribs
sternal angle: importance
marks junction between the manubrium and body of the sternum at vertebral level T4. This is the site of rib 2 articulation, the aortic arch begins and ends, the trachea bifurcates, and the superior mediastinum ends
diaphragm
innervated by phrenic nerve (C3-5), sensory by intercostal nerves.

the paralyzed dome of the diaphragm does not descent during inspiration and is consequently forced upward because of increased abdominal pressure
serratus posterior superior muscle - elevates ribs

serratus posterior inferior muscle - lowers ribs
levator costarum muscle - elevates ribs

the sternocleomastoid, pectoralis major and minor, and scalene muscles attach to the ribs and play a role in inspiration, while the external oblique, internal oblique, transverse abdominal, and rectus abdominis play a role in expiration.
intercostal nerve injury
the intercostal nerves are the ventral primary rami of T1 through T11 (T12 is called subcostal), and run in the costal groove.

**injury is evidenced by a sucking in (on inspiration) and bulging out (on expiration) of the affected intercostal space
arteries of the chest wall
arterial supply to the chest wall comes from 2 main pathways:
1) the internal thoracic artery --> anterior intercostal arteries
2) thoracic aorta --> posterior intercostal arteries
**anastamoses between the anterior and posterior intercostal arteries (and veins) can be important sources of collateral circulation in disease states
Internal thoracic artery
comes off the subclavian, descending just lateral to the sternum and dividing at intercostal space 6 into the superior epigastric and musculophrenic arteries. Gives off the anterior intercostal arteries for spaces 1-6, while the anterior intercostal arteries that supply intercostal spaces 7-9 come off the musculophrenic.
posterior intercostal arteries

**all posterior intercostal arteries give off a posterior branch that travels with the dorsal primary ramus of a spinal nerve to supply the spinal cord, vertebral column, back muscles, and skin.
post. intercostals 1 and 3 come off the superior intercostal artery (from costocervical trunk of subclavian a)

post. intercostal 3-11 come directly off the thoracic aorta (as does the subcostal).
veins of the chest wall

*important anastamoses between these two veins!
1) anterior intercostal veins: drein into the anterior thorax and empty into the internal thoracic veins, which then empty into the brachiocephalic
2) posterior intecostal veins: drain the lateral and posterior thorax and empty into the hemiazygos veins on the left and the azygos vein on the right, which empty into the superior vena cava
breast carcinoma and movement
if breast carcinoma invades the retromammary space and pectoral fascia, contraction of the pec major may cause the whole breast to move superiorly. If breast carcinoma invades the suspensory ligaments (cooper's), you may see dimpling of skin or inversion of nipple.
importance of sensory innervation of nipple/areola
important because stimulation of the nupple and areola by the suckling infant triggers the ejection of milk (oxytocin) and production of milk (prolactin)
nipple secretions

**prolactinoma results from disruption of the infundibulum (stalk effect) - cuts off dopamine to anterior pituitary!
exfoliated duct cells, alpha-lactalbumin, immunoglobulins (IgA), lactose, cholesterol, steroids, and fatty acids, as well as ethanol, caffeine, nicotine, barbituates
colostrum
a premilk fluid secreted during the first 72 hrs after birth - contains immunoglobulins and lactoferrin, and colostrum also stimulates maturation of B lymphocytes and increase activity of macrophages, thereby enhancing immune system
arterial supply of breast
from medial mammary branches of internal thoracic artery, lateral mammary branches from lateral thoracic artery, pectoral branches from thoracoacromial artery, and perforating branches from anterior/posterior intercostal aa.
venous drainage of breast
mainly the axillary vein via lateral mammary veins and the lateral thoracic vein.

mets of breast carcinoma to the brain: cancer cells enter intercostal veins --> external vertebral venous plexuses --> internal vertebral venous plexus --> cranial dural sinuses
the piriformis is the "key" to the gluteal region!

innervated by the ventral rami of S1/S2
the piriformis exits the greater sciatic foramen over the sciatic nerve - it can pinch the sciatic nerve in piriformis syndrome!

the superior gluteal neurovascular bundle exits over the piriformis, while the inferior gluteal neurovascular bundle exits underneath.
obturator nerve
innervates the adductors of the leg (except for the pectineus and the hamstring portion of the adductor magnus). Exiting the obturator foramen, it branches into anterior and posterior divisions around the adductor brevis
tendon often used for grafting

bone often used for grafting

nerve often used for grafting
palmaris longus tendon

fibula

sural nerve
brachial cutaneous innervation
medial - from brachial plexus
superior lateral - from axillary n.
inferior lateral - from radial n.
posterior - from radial n.
antebrachial cutaneous innervation
medial - from brachial plexus
latearl - termination of musculocut. n.
posterior - from radial n.
sural n.
formed by the union of the fibular communicating branch of the lateral sural cutaneous nerve and the medial sural cutaneous nerve.

course posterior to the lateral malleolus with the lesser saphenous v.
axillary/epigastric venous anastamosis
the axillary vein receives one or more thoracoepigastric veins - this represents an anastamosis of veins from the superficial inguinal region - important if the inferior vena cava is obstructed!
subacromial bursitis
indicated by painful abduction with no predisposing trauma or radiographic changes.

The subacromial bursa lies just under the deltoid, between it and the supraspinatus tendon/joint capsule.
4 types of brachial plexus injury:

a. avulsion
b. rupture
c. neuroma
d. neuropraxia
a. pulling the nerve from the spine
b. the nerve is torn, but not at spine
c. the nerve tried to heal itself, but scar tissue prevents conduction
d. the most common type of brachial plexus injury, the nerve is damaged but not torn
what do we worry about in surgical neck fractures of the humerus?
axillary nerve, circumflex humeral artery injury
lymph drainage of the lower limb:

lymph drainage of the upper limb:
lower limb: most lymph flows to superficial inguinal lymph nodes, which drain into the external iliac and deep inguinal nodes (within the femoral canal).

upper limb: mostly ends up in the lateral and central axillary lymph nodes, though lymph vessels following the cephalic vein go straight to the apical nodes
cubital fossa structures
the central structure in the cubital fossa is the tendon of the biceps brachii muscle. medial to the tendon is the brachial artery, and right there is the median nerve as well. The ulnar nerve courses posterior to the medial epicondyle of the humerus
pudental nerve
S2-4
travels through greater sciatic foramen, then loops back around to enter the perineum through the lesser sciatic foramen, entering the pudental canal
God designed reflexes according to a nursery rhyme:
1,2 buckle your shoe: S1/2 ankle
3,4 kick the door: L3/4 knee jerk
5,6 pick up sticks: C5/6 biceps
7,8 shut the gate: C7/8 triceps
glenohumeral joint
glenohumeral bands
glenoid labrum
subscapular bursa
tendon of biceps
transverse humeral ligament
Hip joint:
acetabular labrum
zona orbicularis
iliofemoral ligament (prevents hyperextension)
pubofemoral ligament (prevents overabduction)
ischiofemoral ligament (most at risk in posterior dislocation!)
"torn rotator cuff"
usually the suprapinatus tendon!
posterior shoulder dislocation

**recall that young people are more likely to damage the glenoid labrum, while old people are more likely to damage the suprascapular tendon (rotator cuff injury)
less common than anterior subluxation

Fluid can be seen between the labrum and the glenoid rim on the sagittal view. Hockey player “hit the boards” and had posterior subluxation.
Hip pain in the young athlete:
Atypical hip configurations can result in femoral acetabular impingement.
This can lead to labral tears and then cartilage damage.
Could predispose to early onset osteoarthrosis of the hip.
Insertion of central venous catheter:

1) Internal Jugular vein (central or anterior approach)

2) Subclavian vein (infraclavicular approach)
1)needle inserted at the apex of a triangle formed by the 2 heads of the sternocleomastoid muscle and the clavicle on the right side

2) needle inserted below the clavicle and lateral to the sternal notch.
coarcation of the aorta (general)

With imaging, resorption of the lower part of the ribs may be seen, due to increased blood flow over the neurovascular bundle that runs there. Post-stenotic dilation of the aorta results in a classic 'figure 3 sign' on x-ray.
a congenital condition whereby the aorta narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts.
3 types: preductal, ductal postductal (more common)
May require surgical resection of the narrow segment if there is arterial hypertension.
collateral circulation around a postductal coarctation

collateral circulation around a preductal coarctation

*dilation of the intercostal arteries causes erosion of the lower rib borders, termed "rib notching".
postductal: internal thoracic artery -> intercostal artery -> superior epigastric artery -> inferior epigastric artery -> external iliac artery

**in a preductal coarctation (proximal to the ductus arteriosus), blood reaches the lower limbs via a patent ductus arteriosus!
thoracic outlet syndrome - clinical findings
atrophy of thenar/hypothenar muscles, atrophy of interosseous muscles, sensory deficitson medial side of forearm and hand, diminished radial pulse, and a bruit over the subclavian artery
knife wound to chest wall above the clavicle: may damage:
subclavian a.
lower trunk of brachial plexus (lose ulnar nerve, C8/T1 dermatomes
cervical pleura/apex of lung
fractures of the lower ribs
a rib fracture on the right side may damage the right kidney and liver. A rib fracture on the left side may damage the left kidney and spleen.

A rib fracture on either side may damage the pleura as it crosses rib 12.
superior mediastinum

common pathologies: aortic arch aneurysms, esophageal perforation from endoscopy or malignancy, traumatic rupture of trachea
trachea, esophagus, thymus, thoracic duct

phrenic n., vagus n.

azygos v., SVC, brachiocephalic v.

aortic arch, L common carotid a., L subclavian a.
anterior mediastinum

common pathologies: thymoma associated with myasthenia gravis and RBC aplasia, thyroid mass, germinal cell neoplasm, lymphoma
lies in front of pericardium and middle mediastinum

contains the thymus, lymph nodes
middle mediastinum

common pathologies: pericardial cysts, bronchiogenic cysts, sarcoidosis
contains the pericardium, phrenic nerves, ascending aorta, SVC, coronary arteries/veins
posterior mediastinum

common pathologies: ganglioneuromas, neuroblastomas, or esophageal diverticula or neoplasms
located anterior to T5 through T12 vertebrae, posterior to pericardium

contains: descending aorta, esophagus, thoracic duct, azygos vein, splanchnic nerves, and vagus nerves
regions of parietal pleura
costal pleura
mediastinal pleura (forms the pulmonary ligament)
diaphragmatic pleura
cervical pleura
costodiaphragmatic recesses
costodiaphragmatic recesses - lungs descend into these during inspiration; constodiaphragmatic angle should appear sharp in a posterolateral radiograph - if the angle is blunted, pathological disorder of the pleural space is suspected. If the patient is in a standing position, excess fluid within the pleural cavity will accumulate in the costodiaphragmatic recess
costomediastinal recesses
the lingula of the left lung expands during inspiration to enter a portion of the left costomediastinal recess. During expiration the anterior borders of both lungs recede and exit the costomediastinal recesses
pleuritis = inflammation of the pleura
Pleuritis of the visceral pleura is painless, while pleuritis of the parietal pleura is associated with sharp local pain and referred pain

because the parietal pleura is innervated by intercostal nerves and the phrenic nerve (C3/4/5), pain may be referred to the thoracic wall and root of the neck
open pneumothorax
result of trauma and iatrogenic etiology (thoracocentesis, mechanical ventilation, central line insertion)

loss of negative Pip --> expanded chest wall and collapsed lung.
tension pneumothorax
may occur as a sequela to an open pneumothorax if the inspired air cannot leave the pleural cavity through the wound on expiration. results in collapsed lung on wounded side and *compressed* lung on opposite side because of a deflected mediastinum. chest pain, SOB, absent breath sounds on affected side, hypotension (b/c mediastinal shift compresses vena cava). may cause sudden death.
compression of the trachea
may be caused by an enlargement of the thyroid gland or an aortic arch aneurysm
distortion in the position of the carina
may indicate metastasis of bronchogenic carcinoma into the tracheobronchial lymph nodes, or may indicate enlargement of the left atrium
Aspiration of foreign objects: where does it go?
standing: posterior basal segment of R lower lobe

supine: superior segment of R lower lobe

lying on R side: posterior segment of R upper lobe

lying on L side: inferior lingular segment of L upper lobe
Breath sounds
upper lobe: ascultated on anterior-superior aspect of thorax

lower lobe: ascultated on posterior-inferior aspect of back

middle lobe (R lung): anterior thorax near sternum (just below intercostal space 4)
ligamentum arteriosum
vestige of the ductus arteriosus, the ligamentum arteriosum connects the arch of the aorta to the left pulmonary artery. It is closely related to the left recurrent laryngeal nerve, a branch of the left vagus nerve. Caution must be taken during surgery in this area not to damage this branch.
vasculature of the lung: 2 arterial systems, 2 venous systems

bronchial arteries/veins
pulmonary arteries/veins
the right bronchial artery is a branch of a posterior intercostal artery. the two left bronchial arteries are branches of the thoracic aorta.

the right bronchial veins drain into the azygos vein, while the left bronchial veins drain into the accessory hemiazygos vein.
Innervation of the lung
the lungs are innervated by the anterior and posterior pulmonary plexi, containing both sympathetic and parasympathetic fibers.

postganglionic sympathetic neuronal cell bodies are located in the paravertebral ganglion at the cervical (superior, middle, inferior ganglia) and thoracic (T1-T4) levels.
lymphatic drainage of the lungs

the bronchomediastinal lymph trunk empties into the junction of the internal jugular and subclavian veins
R lung lymph drains: pulmonary nodes (deep) --> bronchopulmonary nodes --> inf/sup tracheobronchial nodes --> paratracheal nodes --> R bronchomediastinal trunk.

Lymph from the left lung follows the same pattern, draining into the left bronchomediastinal trunk - *EXCEPT* for the lower lobe of the left lung, which drains into the right lung pathway.
restrictive lung diseases
1. idiopathic pulmonary fibrosis
2. coal worker pneumoconiosis
3. silicosis
4. asbestosis
5. sarcoidosis
characterized by a decrease in compliance - the lungs are "stiff". Restrictive ventilatory impairment (inability to fully expand lungs) results in less total lung capacity (in contrast to obstructive lung diseases)
idiopathic pulmonary fibrosis

pathology: inflammatory cell infiltrates, thickening alveolar wall b/c of fibroblast activity, destruction of alveoli forming "honeycomb lung"
hypoxemia, slight hypocapnia. **during exercise, hypoxemia worsens without hypercapnia!**

as condition worsens, hypoventilation --> worse hypoxemia, dramatic hypercapnia, respiratory acidosis, decreased diffusion-limited CO
sarcoidosis

common in the SE USA and in young black women
a type IV hypersensitivity rxn. to an unknown antigen. noncaseasting granuloma distributed along the lymphatics of the lung. aggregation of epithelioid cells with langerhans cells and foreign body-type giant cells, asteroid bodies (stellate inclusion bodies w/in giant cells), schaumann bodies (laminated concretions of calcium), and proteins.
cystic fibrosis
deletion of phe at 508 on CFTR gene.

signs: meconium ileus (obstruction of bowel in neonate), steatorrhea or bowel obstruction in childhood, and cor pulmonale (manifesting as R-sided heart failure) secondary to pulmonary hypertension
pericardium layers
visceral layer of serous pericardium (epicardium)
parietal layer of serous pericardium
fibrous pericardium (1mm thick collagen layer with little ability to distend acutely. fused to the great vessels, the diaphragm, the sternum. the phrenic nerve and pericardiophrenic artery are in jeopardy during surgery to the heart
arterial supply/venous drainage/nerve supply of the pericardium
arterial supply is from the pericardiophrenic artery (a branch of the internal thoracic artery) that often accompanies the phrenic nerve. the pericardiophrenic veins drain into the braciocephalic veins. The innervation of the pericardium is the phrenic nerve (C3-5), so pain sensation carried by the phrenic nerves is often referred to the skin of the ipsilateral supraclavicular region (C3-C5 dermatomes)
cardiac tamponade: clinical findings
hypotension that does not respond to rehydration, compression of SVC causing engorgement of veins of face and neck, distension of neck veins on inspiration (Kussmaul sign), paradoxical pulse (inspiratory lowering of BP by >10mmHg), increased venous pressure, distant heart sounds
pericardiocentesis
sternal approach: intercostal space 5 or 6 on L side near the sternum. may damage the internal thoracic artery, coronary arteries, pleura

subxiphoid approach: diaphragm and liver may be damaged
fibrous skeleton of heart:
a. 4 annular rings: tricuspid, mitral, pulmonary, aortic
b. R fibrous trigone (largest & strongest component), L fibrous trigone, intervalvular trigone (collagen connecting all the fibrous rings)
c. conus ligament (connects pulmonary and aortic valves)
tricuspid (right atrioventricular) valve
3 leaflets: anterior, posterior, septal

tethered by anterior, posterior, and medial papillary muscles via chorda tendineae.
bicuspid (mitral, left AV valve)
2 leaflets: anterior and posterior, tethered by anterolateral and posteromedial papillary muscles by chortaes tendinae.
pulmonary semilunar valve

aortic semilunar valve
3 cusps: anterior, right, left

3 cusps: posterior, right, left
Right coronary artery (RCA) and right side dominant heart
the blood supply of the heart is considered right-side dominant (most common) if the posterior interventricular artery arises from the RCA. The RCA branches into the SA nodal a., conus branch, right marginal a., AV nodal a., posterior interventricular a., and septal branches
Left main coronary artery (LMCA)
blood supply of the heart is considered left-side dominant (less common) if the posterior interventricular a. arises from the LMCA. the LMCA branches into: anterior interossesous a. and left circumflex a. (gives off anterior marginal a., obtuse marginal a., atrial branches, and posterior marginal a.
oblique vein of LA - drains into coronoary sinus
L post. ventricular vein drains into coronary sinus
L marginal vein drains into coronary sinus
Anterior cardiac veins on R ventricle drain directly into RA
smallest cardiac veins within heart walls drain directly into chamber
coronary sinus drains directly into RA
great cardiac vein follows anterior interventricular a. and drains into coronary sinus
middle cardiac vein follows posterior interventricular a. and drains into coronary sinus
small cardiac vein follows R. marginal a. into coronary sinus
thrombus formation and thrombolysis
initated by platelet aggregation induced by thromboxane A2 (TXA2). TXA2 is synthesized from arachadonic acid using cyclooxygenase (which aspirin and NSAIDS inhibit). Thrombolysis is stimulated by tissue plasminogen activator, which stimulates the conversion of plasminogen to plasmin. Plasmin is a protease that digests fibrin
visceral pain sensation
carried almost exclusively by the sensory component of the sympathetic nervous system.

poorly localized, complex 4-neuron chain
pelvic splanchnic nerves
preganglionic axons from grey matter of S2-S4 parasympathetic neurons - interact with inferior hypogastric plexus and travel to visceral organs distal to the splenic flexure of the transverse colon.
postganglionic parasympathetic neurons
located in the ciliary (sphincter pupillae and ciliary muscle), pterygopalatine (lacrimal/nasal glands), submandibular (submandibular/sublingual glands), and otic (parotid gland) ganglia, and within various visceral organs and CNX.
arterial supply of the abdominal wall
musculophrenic a. and superior epigastric a. arise from the internal thoracic artery. The superior epigastric anastamosis with the inferior epigastric (from external iliac) between the rectus abdominis and posterior layer of rectus sheath. **This is collateral circulation between the subclavian and external iliac arteries.

the superficial epigastric a. comes off the femoral a. and runs superiorly toward the umbilicus
lymphatic drainage of the abdominal wall

*recall: lower extremities --> deep inguinal nodes --> external/common iliac, lumbar nodes -->--> thoracic duct
most superficial vessels above the umbilicus ultimately drain into the *axillary* lymph nodes! below the umbilicus, superficial drainage is into the superficial inguinal lymph nodes.

deep lymphatic vessels drain into the external/common iliac and lumbar lymph nodes, eventually reaching the cisterna chyli and thoracic duct.
rectus sheath

aponeurosis of external oblique, internal oblique, and transverse abdominis muscles. The rectus sheath encloses the rectus abdominis and pyramidalis muscles.
It is divided by the arcuate line into superior and inferior portions. In the superior portion, the anterior layer of the rectus sheath is made up of the aponeurosis of the external and internal obliques while the posterior layer is made up of the aponeurosis of the internal oblique and transversalis abdominis. The inferior portion is deficient posteriorly because all three muscles contribute to the anterior portion, leaving only the *transversalis fascia* on the posterior surface of the rectus abdominis.
mesenteries


***organs with a mesentery are intraperitoneal, while organs without a mesentery are retroperitoneal!
Most, but not all of the GI organs are suspended "within" the peritoneal cavity by connections to the posterior abdominal wall called mesenteries. These are double-layer sheets of peritoneum containing neurovascular structures between the layers. Mesenteries are named by organ, but "THE mesentery" is what suspends the small bowel.
retroperitoneal structures:

primary (were posterior to peritoneal cavity in embryo)

secondary (became fused to posterior abdominal wall during development)
primary: ex. aorta, IVC, kidney, ureter, adrenals

secondary: pancreas, duodenum, ascending/descending colon

the "fusion fascia" attaches the secondary structures to the posterior abdominal wall!
nerves in the abdominal wall
thoracoabdominal (T7-T11): equivalent to the intercostal nerves in thorax
subcostal (T12): runs like above, innervates wall inferior to umbilicus
iliohypogastric (L1): pierces internal oblique at ant. sup. iliac spine
ilioinguinal (L1): same as above but also innervates scrotum or labia by sending branches through inguinal canal
Camper's fascia

Scarpa's fascia

Colles fascia
Camper's: fatty layer of superficial fascia (beer belly area)

Scarpa's: membranous layer of superficial fascia - continues inferiorly as superficial perineal fascia (Colles fascia), attaches to iliac crest, fascia lata, pubic symphysis
Superficial inguinal ring:
passageway through abdominal wall just superolateral to the pubic tubercle, made by a gap in the external oblique. Transmits ilioinguinal nerve, round ligament (female), spermatic cord/fascia, cremaster muscle (male)
pectineal ligament (Cooper's ligament)

lacunar ligament
Cooper's: a thickening of fascia on the pubic pecten

Lacunar: flattened aponeurosis of external oblique - projects posteriorly from pubic tubercle - forms medial part of femoral ring, floor of inguinal canal
pfannenstiel (suprapubic) incision
made at pubic hairline, horizontal with downward convexity, used for most OBGYN operations
inguinal canal

**at birth, the inguinal canals run almost entirely posterior to anterior, with little medial deviation. with growth and development they assume the oblique arrangement
contents: spermatic cord/round lig., ilioinguinal n. (enters from side, not deep ring!)
openings: deep (outpouching of transversalis fascia), superficial ring (external oblique)
inguinal triangle
weak area between: lateral border of rectus abdominis, inferior epigastric a, inguinal ligament.

direct inguinal hernias pierce here.
cremasteric reflex:
elevation of testes on ipsilateral side to stroking medial aspect of superior thigh - this area is supplied by femoral branches of the genitofemoral nerve
spermatic cord/testis covering
scrotum, scrotum/dartos fascia & muscle, external spermatic fascia, cremaster muscle, cremasteric fascia, internal spermatic fascia, processus vaginalis (obliterated)/tunica vaginalis
relations between inguinal structures and testes coverings

*note that extravasation of urine from a saddle injury will be found within the superficial perineal space, located between Colle's (dartos) fascia and dartos muscle (layer 2) and the external spermatic fascia (layer 3)
peritoneum = tunica vaginalis
transversalis fascia = internal spermatic fascia
transversalis abdominis = *nada*
int. abd. oblique = cremaster m.
ext. abd. oblique = cremaster fascia
scarpa's fascia = dartos fascia/scrotum
varicose superficial epigastric veins
caused by obstruction of either the IVC or the hepatic portal vein, both of which drain structures below the diaphragm
paracentesis:

midline approach
flank approach
midline: skin -> camper's/scarpa's -> linea alba -> transversalis fascia -> extraperitoneal fat -> parietal peritoneum

flank: skin -> camper's/scarpa's -> ext. oblique -> int. oblique -> transverse abdominis -> extraperitoneal fat -> parietal peritoneum
surgical repair hernias
a. Bassini repair: transversalis fascia and conjoint tendon are sutured to the shelving edge of the inguinal ligament (Poupart's ligament)
b. Cooper's ligament repair: transveraslis fascia and conjoint tendon are sutured to the periosteum of pubic ramus
c. *surgical hernia repair may damage the iliohypogastric or ilioinguinal nerves
conjoint tendon
combined tendinous insertion of the transverse abdominis muscle and internal oblique muscle
Direct inguinal hernia
acquired, protrudes directly though anterolateral abdominal wall within inguninal triangle. protrudes *medial* to inferior epigastric a. and v., common in older men; rare in women.

clinical signs include mass in inguinal region that protrudes on straining and disappears at rest (easily reduced)
metastasis of scrotum cancer vs. testicular cancer
scrotum cancer: mets --> superficial inguinal nodes

testicular cancer: mets --> deep lumbar nodes
Extravasated urine from a straddle injury:
found within the superficial perineal space, located between Colle's fascia and dartos muscle (layer 2) and the external spermatic fascia (layer 3)
sacral foramina
dorsal sacral foramina transmits dorsal rami of S1-S5, while the ventral sacral foramina transmits the ventral rami of S1-S5.
greater sciatic foramen

defined by the sacrotuberous and sacrospinus ligaments
divided by the piriformis into the suprapiriformis and infrapiriformis recesses. transmits: superior/inferior gluteal v./a./n.; piriformis m.; sciatic n.; internal pudendal v./a./n.
lesser sciatic foramen
transmits the following structures as they *reenter* the pelvic cavity and proceed to the perineum: internal pudendal v./a./n.

**note that the internal pudendal artery/nerve/vein exit via the greater sciatic foramen and reenter through the lesser sciatic foramen!
Pelvic inlet (pelvic brim)
defined by sacral promontory (S1 vertebrae) and the linea terminals (pubic crest, iliopectineal line, arcuate line). Divides pelvis into major (false) pelvic cavity and minor (true) pelvic cavity. Oval shape = female, heart-shaped = male
2 important diameters of pelvic brim
1) true conjugate diameter: from sacral promontory to superior margin of pubic symphysis. measured radiographically

2) diagonal conjugate diameter: from sacral promontory to the inferior margin of the pubic symphysis. measured during an obstetric examination
pelvic outlet

measure: transverse diameter (btw. ischial tuberosities) and interspinous diameter (btw. ischial spines; can present barrier to childbirth if <9.5cm
defied by coccyx, ischial tuberosities, inf. pubic ramus, and pubic symphysis. closed by pelvic diaphragm and urogenital diaphragm. diamond-shaped in both males and females. divided into the anal triangle and urogenital triangle.
muscles of the pelvis
obturator internus, piriformis, coccygeus, and levator ani muscles (iliococcygeus, pubococcygeus, puborectalis)
divisions of internal iliac artery
anterior division: inf. gluteal, int. pudendal, umbilical, obturator, vaginal/inf. vesical, uterine/artery of the ductus deferens, middle rectal

posterior: iliolumbar, lateral sacral, superior gluteal
median sacral artery
arises from the posterior aspect of the abdominal aorta and runs close to the midline over the L4, L5 vertebrae, sacrum, and coccyx. gives rise to the medial sacral arteries; supplies the posterior rectum, lower lumbar vertebrae, sacrum, and coccyx
venous drainage of the pelvis
very complicated with lots of anastamosing between plexuses. the rectal venous plexus, vesical venous plexus, prostatic venous plexus, uternine venous plexus, and vaginal venous plexus all drain via a number of different pathways leading to the internal iliac veins, median sacral veins, ovarian veins -> IVC, portal veins, lateral sacral veins -> internal vertebral venous plexus -> cranial dural sinuses
pelvic relaxation
damage of pelvic diaphragm, urogenital diaphragm, transverse cervical ligament, uterosacral ligament, pubocervical ligament. May result in cystcele, rectocele, uterine prolapse.
referred pain from kidney disease
may be referred over the T12 through L2 dermatomes; note that the sensory innervation runs with the sympathetic component
sympathetic innervation of kidney

note - no parasympathetic innervation of kidney at all!
the lower part of the celiac ganglion is more or less detached as the aorticorenal ganglion, which is located at the origin of the renal artery. The aorticorenal ganglion receives fibers from the lesser/least thoracic and 1st two lumbar splanchnic nerves and forms most of the renal plexus. Pain with kidney disease is referred over T12 through L2 dermatomes.
Adult polycystic kidney disease
autosomal dominant mutation of ADPKD-1 gene, located on short (p) arm of chromosome 16 (p16) and encodes for the protein polycystin. associated with cystic disease in other organs and berry aneurysms within the circle of Willis. Arises ~40yrs, hematuria, HTN, azotemia, uremia
Childhood polycystic kidney disease
AR mutation of gene on 6p. enlarged spongy kidneys, associated with congenital hepatic fibrosis. end-stage renal disease results in 75% of infants dying in perinatal period
renal cell carcinoma

5% associated with Von-Hippel Lindau
most common cancer of kidney, major types are clear cell carcinoma (most common), papillary carcinoma, chromophobe carcinoma. 95% of cases are sporadic and unilateral - other 5% tend to be bilateral and multifocal.
Wilms Tumor (WT; nephroblastoma)
most common renal maligancy of childhood, presents from 1-3yrs. histologically recapitulates development of kidney. involves WT1 and WT2 gene, both on 11p13 - these are tumor suppressor genes
normal constrictions of the ureter
these 3 locations are where kidney stones are most common!
1) at the uteropelvic junction
2) where the ureters cross the pelvic inlet
3) At the ureterovesical junction (along the intramural portion of the ureter)
vasculature of the ureter
arteries supplying the ureters are multiple and variable. The most constant supply of the lower ureter is the uterine artery in the female and the inferior vesical artery in the male. Inadvertent damage to one of these branches may lead to necrosis of a ureteral segment ~1wk postoperatively
innervation of the ureters (sympathetic, parasympathetic, sensory)
the ureters receive both sympathetic and parasympathetic innervation from complex sources. the key point is that in terms of parasympathetic innervation, the upper ureter gets the vagus nerve and the lower ureter gets S2-S4 inputs. The sympathetic innervation is from all over, and *sensory innervation* is from T12-L2 - so the pain from ureter disease is referred from lumbar region down to anterosuperior thigh.
calcium oxalate calculi
radiopaque, colorless, octahedral crystals, most common type of calculi (80%), formed at acid pH or neutral pH.

Associated with absorptive hypercalcemia, vitamin D intoxication, hyperparathyroidism, diabetes, ethylene glycol poisoning, milk-alkali syndrome... anything that causes hypercalcemia
magnesium ammonium sulfate (struvite; triple phosphate) calculi
second most common calculi (15%), radiopaque, colorless, rectangular crystals, form staghorn calculi, form at alkaline pH.

Associated with UTIs by urea-splitting bacteria (proteus, psuedomonas, klebsiella, staph)
uric acid calculi
*radiolucent!* yellow or red-brown diamond-shaped crystals, third most common calculi (5%), for at acid pH.

Associated with gout, leukemia, Lesch-Nyhan syndrome, myeloproliferative disorders
Cysteine calculi
rare (1%), faintly radiopaque, colorless hexagonal crystals forming at acid pH

caused by cystinurea, an AR inherited disorder
support of the bladder
1. urogenital diaphragm
2. pubovesical ligaments
3. median umbilical ligament (aka. urachus)
4. false ligaments (median umbilical folds, medial umbilical folds, superior/lateral/posterior false ligaments
internal anatomy of the bladder
most of the empty bladder is rough-surfaced; however, the trigone of the bladder is always smooth-surfaced because the mucosa is tightly fused to the detrussor muscle
vasculature of the urinary bladder
arterial supply is complex - comes from vesical arteries from internal iliac, obturator, inferiro gluteal, and branches of the uterine and vaginal arteries in the female. Venous drainage flows into the internal iliac vein and prostatic venous plexus
innervation of the urinary bladder
vesical plexus gets inputs from inferior hypogastric plexus, containing both parasympathetic and sympathetic inputs. Parasympathetics contract the detrussor and relax the internal sphincter, while sympathetics do the opposite. Sensory innervation is carried by both para- and -sympathetics; pain may be referred over S2-S4 dermatomes from the parasympathetics or T11-L2 dermatomes from the sympathetics
1) total incontinence
2) stress incontinence
3) urge incontinence
4) overflow incontinence
1) ectopic uterus or vesiculovaginal fistula treated with surgery
2) stress incontinence - treated by ephedrine, phentolamine, or surgery
3) urge incontinence - uncontrolled detrussor muscle - treated by oxybutynin or imipramine
4) overflow - caused by prostate cancer, stricture of urethra, or atonic neurogenic bladder. treated by catheterization or surgery
hypertonic neurogenic bladder
small urinary bladder, detrussor hyperreflexia causing thickened walls ("pine tree bladder"). associated with upper motor neuron lesions, and is treated with anticholinergics, catheterization and surgical treatment
atonic neurogenic bladder
large urinary bladder, detrussor areflexia - causes urinary retention with subsequent overflow incontinence. associated with *lower* motor neuron lesions, and is treated with catheterization or surgical diversion of urine
primary hyperaldosteronism
Aldosterone secreting adenoma (Conn syndrome) within the zona glomerulosa or adrenal hyperplasia. Characterized by hypertension, hypernatremia, hypokalemia, decreased plasma renin. Tx. surgery or spirolactone (aldosterone-receptor antagonist
zones of the adrenal cortex

note - adrenal cortex is derived embryologically from the mesoderm
1) zona glomerulosa - secretes aldosterone
2) zona fasciculata - secretes cortisol
3) zona reticularis - secretes DHEA and androstenedione
venous drainage of the adrenal glands
the adrenals drain into the right and left adrenal veins; the venous drainage is particularly important during an adrenalectomy because the adrenal vein must be ligated ASAP to prevent catecholamine release into the circulation
omental bursa (lesser peritoneal sac)

lies behind stomach
communicates with the greater peritoneal sac via the omental foramen.

if a surgeon places his fingers in the omental foramen, the IVC will lie posterior and the portal vein will lie anterior
excess peritoneal fluid - where does it go?

note - normally peritoneal fluid flows upward through the pericolic gutters to the subphrenic recess, where it enters the lymphatics associated with the diaphragm
when the patient is sitting or standing, the fluid flows downward through the paracolic gutters to the retrovesical pouch (males) or retrouterine pouch (females).

when supine, peritoneal fluid flows upward through to the subphrenic recess and hepatorenal recess. The patient may complain of shoulder pain from phrenic nerve irritation. **the hepatorenal recess is the lowest part of the peritoneal cavity when the patient is supine!
1) lesser omentum

2) portal triad
1) the lesser omentum is a fold of peritoneum that extends from the porta hepatis to the lesser curvature of the stomach. It consists of the hepatoduodenal ligament and the hepatogastric ligament.

2) the portal triad lies in the free margin of the hepatoduodenal ligament and consists of the: portal vein, common bile duct, hepatic artery
greater omentum
a fold of peritoneum that hangs from the greater curvature of the stomach, the greater omentum is known as the "abdominal policeman" because it *adheres* to areas of inflammation.
abdominal vasculature and areas of vascularization
celiac trunk (T12): vascularizes the foregut (to mid-duodenum). Branches: left gastric, splenic, common hepatic arteries

SMA (L1): vascularizes midgut (mid-duodenum to splenic flexure)

IMA (L3): vascularizes hindgut
Abdominal aortic aneurysm (AAA)
atherosclerotic elderly men below L1 (below renal arteries and SMA). Occurs left posterolateral wall (retroperitoneal). First step is compression of aorta above the celiac trunk. The IMA generally lies in the middle of an AAA. Surgical complications include ischemic colitis caused by ligation of IMA or spinal cord ischemia from ligation of the great radicular artery
Acute mesenteric ischemia
most commonly caused by an embolus within the SMA. Signs include severe abdominal pain out of proportion to the physical findings and no evidence of peritonitis - usually occurs in elderly patients with heart disease taking digitoxin
gradual occlusion of the abdominal aorta
most commonly seen in atherosclerotic patients at the bifurcation of the abdominal aorta - may result in claudication and impotence (result of the lack of blood in the internal iliac arteries)
if you have an abdominal aortic blockage at L2 (i.e. between the superior mesenteric artery and the inferior mesenteric artery), where would you get arterial collateral circulation? venous collateral circulation?

note - the gonadal arteries might be at risk here!
the middle colic artery anastamoses with the left colic artery. The marginal artery provides a second means of collateral circulation.

Azygos --> SVC --> right atrium is venous, as well as through the lumbar veins --> cranial dural sinuses --> internal jugular vein
abdominal azygos venous system
the azygos vein drains blood from the IVC to the SVC. the hemiazygos vein ascends on the left side of the vertebral column, and drains blood from the left renal vein to the azygos vein
drainage of the gonadal veins - when is the anatomy important?

men? women?
the right gonadal vein drains directly into the IVC, whereas the left gonadal vein drains into the left renal vein.

this is important in women in whom the appearance of a right-side hydronephrosis may indicate thrombosis of the right ovarian vein, constricting the ureter. In men, the appearance of a left-side testicular varicoele may indicate occlusion of the left testicular vein or left renal vein because of a malignant tumor of the kidney
malignant tumors of the esophagus
most commonly occur in the lower 1/3 of the esophagus and metastasize below the diaphragm to the celiac lymph nodes
posterior esophageal tears (alcoholism, bulimia, pregnancy)

1) Mallory-Weiss tears
2) Boerhaave syndrome
1) Mallory-Weiss tears involve only the mucosal and submucosal layers

2) Boerhaave syndrome involves tears through all layers of the esophagus
sliding hiatal hernia
occurs when the stomach, along with the gastro-esophageal junctoin, herniates through the diaphragm into the thorax. Clinical findings include severe retrosternal pain and reflux of gastric contents into the mouth (heartburn) which are *accentuated in the supine position*
paraesophageal hiatal hernia
occurs when only the stomach herniates through the diaphragm into the thorax. So we don't get reflux, but strangulation or obstruction may occur.
Esophageal strictures (narrowing)
Caustic strictures are caused by ingestion of caustic agents (drano). Other stricutres are caused by recurrent mucosal destruction as a result of GERD - often at the gastroesophageal junction
esophageal varices

- caused by portal hypertension (cirrhosis of the liver)
the esophageal venous plexus drains into the left gastric (coronary) vein, which empties into the portal vein from the distal esophagus and proximal stomach.
The anatomic vs. histologic gastroesophageal junction
the ANATOMIC gastroesophageal junction is easy to see, but it doesn't match the histology! The mucosal lining of the cardiac portion of the stomach extends ~2cm into the esophagus (simple columnar epithelium instead of stratified squamous epithelium). The mucosal GE junction can be seen easily as a zigzag line
Barrett's esophagus:
the replacement of esophageal stratified squamous epithelium with metaplastic "intestinalized" simple columnar (with goblet cells) epithelium extending *at least 3cm* into the esophagus.

Virtually all lower esophageal adenocarcinomas occur as a sequela!
general features of the stomach
1. cardia - near the GE junction
2. fundus - above the GE junction
3. body - between fundus and atrum
4. pylorus - divided into the pyloric antrum (wide part) and the pyloric canal (narrow part). the pyloric sphincter prevents reflux of duodenal contents into the stomach
gastric ulcers

NSAIDs, type B chronic atrophic gastritis, smoking, mucosal inschemia from reduced PGE production, or bile reflux
usually occurs in the body of the stomach along the lesser curvature above the incinsura angularis at a histologic transition zone where the gastric glands change from mostly parietal cells to G cells.

H. pylori associated with 80% of cases! Pain SOON after eating, pain WITH food, treatment same as duodenal ulcers
Dumping syndrome
abnormally rapid emptying of *hyperosmotic* stomach contents (especially high-carb foods) into the jejunum within 30 minutes after a meal (early dumping) or 1-3 hrs later (late dumping). Usually occurs after a vagotomy or partial gastrectomy for treatment of an ulcer or obesity. Clinical findings include epigastric discomfort, borborygini, dizziness, diarrhea, and hypoglycemia
carcinomas of the stomach
usually in the pylorus, may metastasize to the supraclavicular lymph nodes (Virchow's nodes) on the *left* side, which can be palpated through the posterior triangle of the neck. Carcinoma of the stomach may also metastasize to the ovaries, where it is called a *Krukenberg tumor*.
superior duodenum
superior part: first 2cm = duodenal cap. Gastroduodenal junction is marked by prepyloric veins. Posterior relationships include the common bile duct and gastroduodenal artery. the hepatoduodenal ligament attaches superiorly and the greater omentum attaches inferiorly
1. descending duodenum
2. horizontal duodenum
3. ascending duodenum
1. receives common bile duct and main pancreatic duct at the hepatopancreatic ampulla
2. runs along L3 vertebrae btw SMA and aorta anteriorly and the IVC posteriorly.
3. duodenojejunal junction at L2 2-3cm to the left of midline. The duodenojejunal flexure, which is supported by the ligament of Treitz
perforations of the duodenum
usually occurs with ulcers on the *anterior wall* of the duodenum. More rarely occurs posteriorly, but these can put the gastroduodenal artery at risk. Clinical findings include air under the diaphragm and pain that radiates to the left shoulder
the appendix and appendicitis

key points: nausea, vomiting, anorexia, tenderness to palpation
the appendix lives in the retrocecal fossa, is supported by the mesoappendix, and gets its own artery from the ileal artery. Key point - pain starts epigastric (visceral peritoneum pain) and migrates to lower R quadrant (parietal peritoneum pain). complications can include peritonitis
Hartmann's pouch

Aschoff sinuses
a small pouch in the gallbladder which may extend from the neck as a sequale to pathologic changes - this is a common site for gallstones to lodge.

Aschoff sinuses occur when the mucosa of the gallbladder penetrates deep into the muscularis externa - they are an early indicator of pathologic change (e.g. acute cholecystitis or gangrene)
innervation of the gallbladder
sensory nerve fibers for pain from the gallbladder travel with the greater thoracic splanchnic nerve (T7-T10).

motor nerve fibers that stimulate contraction of the gallbladder are from the Vagus.
control of gallbladder secretion:
vagus nerve stimulates contraction
CCK stimulates contraction

somatostatin inhibits contraction
sympathetics inhibit contraction
sphincter of Oddi
the sphincter of Oddi is an area of thickened smooth muscle that surrounds the bile duct as it traverses the ampulla. The sphincter of Oddi *controls bile flow* (sympathetic innervation causes contraction of the sphincter).
Bile


*note - lactated Ringer's solution is a good replacement fluid for bile loss
made by hepatocytes, bile is made up of bilirubin glucuronide (bile pigment), cholic acid and chenodeoxycholic acid conjugated to glycine or taurine (bile salts), cholesterol and lecithin, calcium, and secretory IgA. The function of bile is to emulsify fats
hepatic, biliary ducts
The right and left hepatic ducts join together after leaving the liver to form the common hepatic duct. The common hepatic duct is joined at an acute angle by the cystic duct to form the common bile duct. The common bile duct is joined by the pancreatic duct at the hepatopancreatic ampulla. **This anatomy is important for the differential effects of gallstone obstruction in different locations!
Gallstones
gallstones form when bile salts and lecithin are overwhelmed by cholesterol. Most stones consist of cholesterol (major component), bilirubin, and calcium there are 3 major types of stones: 1. cholesterol stones, 2. pigment (bilirubin) stones, 3. calcium bilirubinate stones.
a. Cholesterol stones

b. Pigment (bilirubin) stones

c. Calcium bilirubinate stones
a. Cholesterol stones are yellow, large, smooth, and are associated with obesity, chron disease, CF, estrogens, rapid weight loss, and white ancestry (the F's)
b. pigment stones are brown or black, smooth, and associated with chronic RBC hemolysis, alcoholic cirrhosis, biliary infection, and asians.
c. calcium bilirubinate stones are associated with infection or inflammation of the biliary tree
3 clinically important sites of gallstone obstruction:
1. WITHIN THE CYSTIC DUCT
2. within the common bile duct
3. at the hepatopancreatic ampulla
Within the cystic duct:
biliary colic, acute cholecystitis, pain shifts to right hypochondriac region. Bile concentrates and precipitates in the gallbladder as "milk of calcium" bile from large amounts of calcium carbonate. No jaundice.
3 clinically important sites of gallstone obstruction:
1. within the cystic duct
2. WITHIN THE COMMON BILE DUCT
3. AT THE HEPATOPANCREATIC AMPULLA
Within the common bile duct: inflammation of both liver and gallbladder. Jaundice first appears under the tongue, and fluctuates as a stone rarely causes complete blockage of the lumen.
Gallstone obstruction at the hepatopancreatic ampulla can be most severe, blocking liver, gallbladder, and pancreas, causing jaundice and pancreatitis.
Hepatobiliary iminodiacetic acid (HIDA) scan
HIDA makes use of a radioactive nucleotide bound to bilirubin analogues, which is injected by IV and excreted into the bile.

**morphine injection contracts the sphincter of Oddi and leads to a rise in biliary system pressure
liver stroma

porta hepatis
the liver stroma consists of reticular fibers (type III collagen), and begins as a thin connective tissue capsule called the Glisson capsule.

The porta hepatis consists of 1) common bile duct, 2) portal vein, 3) hepatic artery, 4) lymphatics.
falciform ligament and ligamentum teres


*note - the liver is secured by the attachment of the hepatic veins to the IVC, which allow very little movement of the liver!
the left lobe of the liver contains the falciform ligament (a derivative of the ventral mesentery) with the ligamentum teres (a remenant of the left umbilical vein) along its inferior border.
liver biopsy
made by needle puncture through the right intercostal space 8, 9, or 10 when the patient has exhaled. The needle has to pass through the obliques, the costal parietal pleura, into the costodiapragmatic recess, *through the diaphragm*, then through the peritoneum!
Congenital biliary atresia
generally presents within weeks of birth - this is the most common cause of persistent jaundice in infancy! BUT, doesn't appear immediately after birth as with physiologic jaundice! Also see dark urine, clay-colored stools; liver biopsy shows bile duct proliferation with dilation of bile canaliculi and bile plugs.
primary sclerosing cholangitis
caused by inflammation, fibrosis, and segmental dilation of both intrahepatic and extrahepatic bile ducts! frequently seen with chronic ulcerative colitis of the bowel. Findings include right hypochondriac pain or painless jaundice, no fevers or chills, pruritus, fatigue, and nausea
primary biliary cirrhosis
autoimmune granulomatous destruction of medium-sized intrahepatic bile ducts, with cirrhosis appearing late in the disease. Usually appears in middle-aged women, it is characterized by *mitochondrial pyruvate dehydrogenase autoantibodies*. Primary biliary cirrhosis is often associated with other autoimmune disorders
surgical resection of the liver
5 total liver segments (9 liver subsegments). **Hepatic veins form the surgical landmarks that mark the border of a liver segment. Recall that pulmonary veins form the surgical landmarks that mark the periphery of a bronchopulmonary segment during a partial lung resection
head (including uncinate process), neck, body, tail of pancreas - anatomic relationships

**note that most of the pancreas is retroperitoneal, but the tail of the pancreas is intraperitoneal! just like the duodenum - the first 2 cm is intraperitoneal, and the rest is retroperitoneal!
head: firmly attached to descending and horizontal duodenum. related posteriorly to IVC, right renal artery/vein, and left renal vein
neck: related posteriorly to confluence of SMV and splenic vein to form portal vein
body: related posteriorly to aorta, SMA, left kidney, renal artery/vein
tail: related to splenic hilum and left colic flexure
arterial supply of the pancreas:

**note that anastomosis between the superior and inferior pancreatoduodenal arteries provides an anastomosis between the celiac trunk and the SMA!
anterior and posterior *superior* pancreatoduodenal arteries - branches of the gastroduodenal artery. anterior and posterior *inferior* pancreatoduodenal arteries - branches of the SMA. Dorsal/great/caudal pancreatic arteries are branches of the splenic artery and supply the body/tail of pancreas
exocrine pancreas
secretion of digestive enzymes is stimulated by CCK (released by I-cells of small intestine). Secretion of HCO3- by the intercalated and intralobular ducts is stimulated by secretin, released by S-cells of the small intestine!
acute pancreatitis
about 80% of acute pancreatitis cases are associated with biliary tract disease or alcoholism. Its most severe form is known as acute hemorrhagic pancreatitis. Clinical findings include epigastric pain radiating to back, nausea, vomiting, elevated amylase or lipase levels, and retroperitoneal hemorrhage that may lead to flank ecchymosis (Turner sign) or periumbilical ecchymosis (Cullen sign)
pancreatic adenocarcinoma
90% ducts, 10% islets. usually within the head of the pancreas, more common in men 60-80yrs, p53/ras mutations. midepigastric pain that radiates to the back and worsens on lying down, weight loss, obstructive jaundice, clay-colored stools, hepatomegaly, glucose intolerance, and **elevated CA19-9. May treat with a Whipple procedure
Whipple procedure
a pancreaticoduodenectomy

removes head of pancreas, duodenum, distal common bile duct, gallbladder, and distal stomach
1) diverticulosis

2) Hirschsprung disease (colonic aganglionosis)
1) usually sigmoid colon in patients over 60yrs. associated with Western diet. Perforation or inflammation of the diverticula results in diverticulitis. Pain in left lumbar region, palpable inflammatory mass in left lumbar region, fever, leukocytosis, ileus, and peritonitis.

2) no neural crest in rectum/sigmoid colon. **Think mutations of RET proto-oncogene!
rectal prolapse
protrusion of the *full thickness of the rectum* through the anus (should be distinguished from mucosal prolapse).

caused by stretching of the internal and external anal sphincters or stretch injury to the *pudental nerve*
anal canal

**the upper anal canal is supplied by the superior rectal artery (a branch of the IMA) and drains to the superior rectal vein ( --> IMV --> hepatic portal system).
**the lower anal canal is supplied by the inferior rectal artery (branch of the internal pudendal artery) and drains to the inferior rectal veins (--> internal pudendal vein --> internal iliac --> IVC)
divided into upper and lower anal canal by the pectinate line. The anal canal is surrounded by the internal anal sphincter (involuntary autonomic control) and external anal sphincter (voluntary control via the pudental nerve)
internal hemorrhoids
varicosities of the *superior rectal veins*. They are located above the pectinate line and are covered by rectal mucoas. Clinical findings include: bleeding, mucous discharge, prolapse, pruritus, and pain.
external hemorrhoids
varicosities of the *inferior rectal veins*. they are located below the pectinate line near the anal verge and are covered by skin. Clinical findings include: bleeding, swelling, and pain
defecation reflex
pressure-sensitive receptors within ampulla of rectum travel to sacral spinal cord. motor impulses travel with the pelvic splanchnic nerve, which increase peristalsis and relax the internal anal sphincter. The hypogastric plexus and lumbar splanchnic nerves (sympathetics) decrease peristalsis and maintain tone of the internal anal sphincter
spleen location
anterior to 9th, 10th, and 11th rib - the spleen does not extend below the costal margin, and therefore is not palpable unless spleomegaly is present. It is attached to the stomach by the gastrosplenic ligament, which contains short gastric arteries and veins and the left gastroepiploic artery and vein.
accessory spleens
accessory spleens occur in 20% of the population and are commonly located near the hilum or tail of the pancreas, or within the gastrosplenic ligament
functions of the spleen
removal of inclusion bodies from RBCs (e.g. Howell-Jolly bodies [nuclear remnants]; Pappenheimer bodies [iron granules]; Heinz bodies [denatured Hgb]), removal of poorly opsonized pathogens, IgM production by plasma cells, storage of platelets, and protection from infection
arterial supply of the spleen
the splenic artery gives off the dorsal, great, and caudal pancreatic arteries, short gastric arteries, the left gastroepiploic artery, and ends with five terminal branches. **Obstruction or ligation of any terminal branch will result in splenic infarction (i.e. the spleen is very prone to infarction!)
splenic artery aneurysms

splenic vein thrombosis
splenic artery aneurysms show a particularly high incidence of rupture in pregnant women such that these aneurysms should be resected in women of childbearing age.

splenic vein thrombosis is most commonly associated with pancreatitis and shows gastric varices and upper GI bleeding
splenectomy

note - gotta watch out for the gastric wall, tail of pancreas, and left kidney
the most common complication is *atelectasis of the left lower lobe of the lung*. Thrombocytosis (increased platelets) is common post-op, so anticoagulation therapy might be necessary to prevent spontaneous thrombosis. Abnormal RBCs with weird shapes and Howell-Jolly bodies are found in the blood post-op
overwhelming postsplenectomy sepsis

(post-splenectomy patients are especially susceptible to bacterial infections)
post-splenectomy patients have less opsonin and IgM levels, and decreased clearance of bacteria from blood. Strep pneumoniae, H influenzae, and Neisseria meningitidis are most common.
autosplenectomy
patients with sickle cell anemia usually undergo "autosplenectomy" as a result of multiple infarcts and are therefore prime targets for overwhelming postsplenectomy sepsis. Clinical signs include influenza-like symptoms that progress to high fever, shock, and death
Hypersplenism
increased splenic function - NOT the same as splenomegaly! Findings include anemia (pallor), leukopenia (easy infections), thrombocytopenia (easy bruising), and a compensatory increase in bone marrow activity. Can be caused by hematopoietic disorders (hereditary spherocytosis, thalassemia) or immune disorders (immune thrombocytopenic purpura)
hereditary spherocytosis
deficiency in the *spectrin* protein usually caused by a mutation in the gene for *ankyrin*. Results in anisocytosis (variation in RBC size) and spherocytes with no central pallor zone. Signs include anemia, fatigue, jaundice, pigmented gallstones, and splenomegaly. Treatment is splenomegaly for all patients
Immune thrombocytopenic purpura
IgG directed against platelet-associated antigen causes rapid destruction of platelets. Signs include low platelets, easy bruising, petechiae, bleeding, increased megakaryocyte count. Treatment is prednisone, platelet transfusion, and plasmapheresis. Splenectomy is recommended if steroids don't work
splenomegaly
can be caused by a ton of conditions - autoimmune, infectious disease, infiltrative disease, extramedullary hepatopoiesis, and vascular congestion. In the United States, myeloproliferative disease and lymphoid malignancies are the most common causes of massive splenomegaly
ovaries
located *posterior* to the broad ligament, attached to the lateral pelvic wall by the suspensory ligament of the ovary. the arterial supply is via the ovarian arteries (from abdominal aorta) and ascending branches of uterine arteries (from internal iliac). venous drainage is via a pampiniform plexus to the right ovarian vein (to IVC) and left ovarian vein (to left renal vein)
Ovarian cancer

associated with HNPCC, p53 mutations. carcinoembryonic antigen (CEA) and CA-125 are useful markers in diagnosis
can develop from oocytes (oocyte or germ cell tumors), follicular cells, stromal cells, or germinal epithelium (ovarian covering). The most common type is a germinal epithelium tumor.

Lymph drainage is to the deep para-aortic lymph nodes (aka. lumbar nodes). Some germ cell cancers produce hCG and AFP.
ovarian cysts
originate from either unruptured Graffian follicles or in Graffian follicles that have ruptured and immediately sealed. These are nonneoplastic, fluid-filled cavities that may be solitary or multiple (up to 2 cm in diameter). There are 3 main types: Follicular cysts, corpus luteum cysts, and theca lutein cysts (caused by elevated hCG during pregnancy)
Ovarian cysts:

Follicular cysts
Corpus luteum cysts
Theca lutein cysts
Follicular cysts: large (>2m), may be diagnosed by palpation or ultrasound
Corpus luteum cysts: lined by a conspicuous rim of granulosa lutein cells
Theca lutein cysts: **caused by eleveated levels of hCG produced by the placenta during pregnancy
Polycystic ovary syndrome
characterized by increased levels of androgens and LH but decreased levels of FSH. This results in bilateral ovarian enlargement, cortical fibrosis, and multiple follicular cysts. Clinical findings include chronic anovulation with menstrual irregularities such as oligomenorrhea or amenorrhea, oily skin and acne, hirstism, and obesity
Right side hydronephrosis in the female
may indicate thrombosis in the right ovarian vein that constricts the ureter (because the right ovarian vein crosses the ureter to enter the IVC)
ovarian referred pain
often referred down to the inner thigh via the obturator nerve
acute and chronic salpingitis

salpingitis is probably the most common cause of female sterility
bacterial infection (N. gonorrhea or C. trachomatis) of the uterine tube with inflammation which may lead to scarring of the uterine tube predisposing to *ectopic tubal pregnancy*.
ectopic tubal pregnancy
most commonly occurs in the *AMPULLA*. Risk factors include salpingitis, pelvic inflammatory disease, pelvic surgery, or exposure to DES.
normal position of the uterus
anteverted and anteflexed, placing it in a nearly horizontal position on top of the bladder
endometrial adenocarcinoma
most common gynecologic cancer, linked to prolonged estrogen stimulation of the endometrium. risk factors include exogenous estrogen treatment, obesity, diabetes, nulliparity, early menarchy, late menopause
endometriosis

results in infertility, dysmenorrhea, and pelvic pain (most pronounced at the time of menstruation)
the presence of endometrial glandular tissue in abnormal locations outside of the uterus (80% in ovary). Early foci appear as red or blue nodules ("mulberry nodules"). Foci grow and shrink in cycle with endometrium of uterus; repeating bleeding/hemosiderin forms "gunpowder mark" lesions. In the ovary, repeated bleeding may lead to the formation of "chocolate cysts" in the ovary
uterine fibroids

may cause infertility
a common benign neoplasm resulting from proliferation of smooth muscle in the uterus, which *may become calcified. May be intramural, submucosal (beneath endometrium - grow into uterine cavity) or subserosal (may grow into peritoneal cavity)
clinical evaluation of secondary amenorrhea

**don't forget - the most common cause of secondary amenorrhea is pregnancy!! (check hCG)
evaulated by assaying serum FSH and LH levels along with a progesterone challenge. Bleeding after a *progesterone withdrawl test* indicates that the endometrium was primed by estrogen, thereby indicating the HPG axis is functioning normally.
1) menorrhagia

2) dysmenorrhea

3) metrorrhagia
1) excessive bleeding at menstruation - associated with a leiomyoma (fibroids)

2) excessive pain during menstruation - associated with endometriosis and increased prostaglandin F in menstrual fluid

3) bleeding occurring at irregular intervals - associated with cervical carcinoma or cervical polyps
prepubertal bleeding

postmenopausal bleeding
prepubertal bleeding is associated with vaginitis, infection, sexual abuse, or embryonal rhabdomyosarcoma

postmenopausal bleeding is associated with malignant tumors of the uterus
cervical relaxation during childbirth
the wall of the cervix is predominantly connective tissue with very little smooth muscle. During childbirth, the connective tissue becomes pliable ("cervical softening") because of the action of RELAXIN
transformation zone of the cervix and Nabothian cysts

nabothian cyst = stratified squamous epithelium grows over mucous-secreting glands
at puberty, the simple columnar epithelium of the endocervix extends onto the ectocervix; the acidic environment of the vagina induces squamous metaplasia and the formation of a transformation zone. This is the site of Nabothian cysts, and the most common site of squamous cell carcinoma of the cervix.
the vagina forms a recess around the cervix called the fornix, which is divided into 3 regions
1) anterior fornix: related to vesicoterine pouch

2) lateral fornices

3) posterior fornix is related to the rectouterine pouch. This is a site for culdocentesis
Bartholin cysts
caused by an obstruction of the duct from the greater vestibular glands of Bartholin
Vaginitis - common causes
Trichomonas vaginalis (15%, pH > 4.5), Candida albicans (25%, "cottage cheese", pH < 4.5), Gardnerella vaginalis (30% - "bacterial vaginosis" - fishy odor - whiff test! also see "clue cells"! pH > 4.5.)
clitoris
the clitoris has NO corpus spongiosum - just corpus cavernosum!

the glans of the clitoris is formed by the fusion of the vestibular bulbs
collateral circulation for the testes

note - venous drainage is to the right testicular vein (IVC) and left testicular vein (left renal vein), while lymphatic drainage of the teste is to the deep lumbar nodes near the renal hilus (vs. scrotum, which drains to superficial inguinal nodes)
mostly from the abdominal aorta via the testicular arteries, collateral circulation comes from the artery of the ductus deferens, the inferior epigastric artery via the cremasteric artery, and the femoral artery via the external pudendal artery.
appearance of a left-sided testicular varicocele may mean... what?
may indicate occlusion of the left testicular vein or left renal vein as a result of a malignant tumor of the kidney.
yolk sac tumor
most common form of testicular cancer in infants and children up to 3 years of age. *it is associated with elevated alpha-fetoprotein levels
seminoma
most common type of germ cell neoplasm in men 20-40yrs; painless testicular mass. About 90% of testicular cancers arise from germ cells. Seminoma is associated with elevated hCG levels!
testicular teratoma
germ cell neoplasm, looks like a blastocyst with 3 primary germ levels ("male pregnancy) in early stages.
5-alpha reductase deficiency
underdevelopment of penis and srotum (microphallus, hypospadis, and bifid scrotum) and prostate gland. *The epididymis, ductus deferens, seminal vesicle, and ejaculatory duct are normal. At puberty, these individuals demonstrate a striking virilization. **An increased T:DHT ratio is diagnostic (normal = 5, 5aR deficiency = 30)
17b-Hydroxysteroid dehydrogenase (HSD) deficiency
can't make testosterone from androstenedione; this is the most common defect in androgen biosynthesis! The clinical findings are very similar to 5-alpha-reductase deficiency
vasectomy
to reach ductus deferens, cut through: skin, Colles' fascia and dartos muscle, external spermatic fascia, cremasteric fascia and muscle, internal spermatic fascia, extraperitoneal fat. *the tunica vaginalis is not cut
seminal vesicle secretion

note - in forensic medicine, the presence of fructose and choline crystals is used to determine the presence of semen
secretion product is a whitish-yellow viscous material containing fructose, choline, proteins, amino acids, ascorbic acid, citric acid, and prostaglandins
bulbourethral gland (of Cowper) secretions
fluid contains galactose, galactosamine, galacturonic acid, sialic acid, and methylpentose

this fluid makes up the majority of the preejaculate fluid
prostatic fluid
contains citric acid, prostatic acid phosphatase (PAP), prostaglandins, fibrinogen, and PSA.
venous drainage of the prostate and implications: 2 pathways
1) prostatic venous plexus -> internal iliac v. -> IVC. this is why prostate cancer heads to the heart and lung

2) prostatic venous plexus -> vertebral venous plexus -> cranial dural sinuses. This is why prostate cancer goes to the vertebral column and brain
benign prostatic hypertrophy
hyperplasia of the transitional (periurethral) zone. BPH is NOT premalignant. Treatment may include 5-alpha-reductase inhibitors (finasteride), or alpha-adrenergic antagonists to inhibit prostate gland secretions (terazosin, prazosin)
Prostatic carcinoma

Treatment includes leuprolide (GnRH agonist), cyproterone or flutamide (androgen receptor antagonists), radiation, or prostatectomy
most commonly found in the peripheral zone; by the time urethral blockage occurs, the carcinoma is in an advanced stage. *prostatic intraepithelial neoplasia (PIN) is frequently associated with prostatic carcinoma. metastasis to bone is frequent
Hypospadias

Epispadias
Hypospadias occurs when the urethral folds fail to fuse completely, resulting in the external urethral orifice opening onto the ventral surface of the penis. It is generally associated with a poorly developed penis that curves ventrally, known as chordee.

Epispadias occurs when the external urethral orifice opens onto the dorsal surface of the penis. It is associated with extrophy of the bladder.
Erection and secretions
controlled by the pelvic splanchnic nerves as well as the somatic nervous system via the perineal branch of the pudendal nerve.

Emission from the penis is controlled by the lumbar and sacral splanchnic nerves, while ejaculation is controlled via the pudendal nerve.
MP Joint adduction/abduction and flexion

PIP flexion

DIP flexion
MP: adduction and abduction accomplished by palmar and dorsal interossei, respectively. Flexion is accomplished by flexor digitorum superficialis/profundus and lumbricals.

PIP flexion accomplished by flexor digitorum superficialis

DIP flexion accomplished by flexor digitorum profundus
rotator cuff components
subscapularis (subscapular nerve)

infraspinatus (suprascapular n)

teres minor (axillary n)

supraspinatus (suprascapular n)
Branches of the femoral artery

*medial circumflex provides main blood supply to head of femur in adult.

*lateral circumflex participates in cruciate anastamosis and sends a descending branch to the genicular anastamosis around the knee joint.
1. superficial epigastric
2. superficial circumflex iliac
3. superficial external pudendal
4. deep external pudendal
5. descending genicular
6. profunda femoris (perforating arteries, medial and lateral circumflex)
injection of dye into the right vs. left subclavian veins and the visualization of the circle of Willis
Injection of dye into the right subclavian will visualize the entire circle of Willis, because the dye will enter both the right common carotid and the right vertebral artery. However, dye in the left subclavian will only visualize the posterior portion of the circle of Willis, because the dye will only enter the left vertebral artery!
Heart surfaces
posterior (base): left atrium (T6-9)
Apex: left ventricle (intercostal space 5)
Anterior: right ventricle
Inferior (diaphragmatic): left ventricle
Left: left ventricle
Right: right atrium
Heart borders
Right: right atrium, SVC, IVC

Left: left atrium/ventricle, pulmonary trunk, aortic arch

Inferior: right ventricle

Superior: right atrium, left atrium, SVC, ascending aorta, pulmonary trunk
pericarditis
inflammation of the visceral layer of serous pericardium (epicardium) and the parietal layer of serous pericardium
superficial veins of the abdominal wall

*varicose superficial epigastric veins are caused by obstruction of either the IVC or portal vein, both of which drain structures below the diaphragm.
1. internal thoracic (--> subclavian)
2. lateral thoracic (--> axillary)
3. superficial epigastric (--> femoral vein)
4. inferior epigastric (--> external iliac)
5. thoracoepigastric (may develop between superficial epigastric and lateral thoracic)
6. paraumbilical (tributaries of the portal vein)
Inguinal ligament

Deep inguinal ring

Superficial inguinal ring
Inguinal ring: coiled lower border of the external oblique mm.

Deep inguinal ring: an opening of the transversalis fascia (lateral to the inferior epigastric)

superficial inguinal ring: defect of the external oblique muscle located lateral to the pubic tubercle
nerve damage in surgical hernia repair
surgical hernia repair may damage the iliohypogastric nerve, causing anesthesia of the ipsilateral abdominal wall and inguinal region, or the ilioinguinal nerve, causing anesthesia of the ipsilateral penis, scrotum, and medial thigh.
pancreatic divisum

**these patients are prone to pancreatitis, especially if the opening of the dorsal pancreatic duct at the minor papillae is small!
occurs when the distal 2/3 of the dorsal pancreatic duct and the entire ventral pancreatic duct fail to anastomose and the proximal 1/3 of the dorsal pancreatic duct persists. The dorsal duct drains the body, tail, and part of the head, while the ventral duct drains the uncinate process and a portion of the head through the major papillae.
Apex of the bladder: related structures

*note that the neck of the bladder (male) is related to the prostate gland and prostatic urethra. In females, the neck is related to the urogenital diaphragm.
The apex is related to 1 median umbilical ligament (aka urachus - remnant of the allantois), 2 medial umbilical ligaments (remnants of the right and left umbilical veins), and 2 lateral umbilical ligaments (elevations formed by the right and left inferior epigastric arteries and veins)
Micturition reflex

*note that the external urethral sphincter is innervated by the pudendal nerve and is voluntarily relaxed!
stretch from bladder fullness is carried by afferents that run with pelvic splanchnic nerves. The efferent limb also runs with pelvic splanchnic nerves, and causes contraction of the detrussor and relaxation of the internal urethral sphincter.
support of the uterus

**note: the uterus is divided into the fundus (top - can reach the xiphoid at term pregnancy!), cornu, body, and cervix.
1. pelvic diaphragm (levator ani), 2. urogenital diaphragm, 3. urinary bladder, 4. round ligament (gubernaculum remnant), 5. uterosacral ligament, 6. pubocervical ligament (prevents cystocele), 7. transverse cervical ligament (contains uterine artery), 8. broad ligament
The broad ligament

**contains the ovarian artery/vein/nerve, round and ovarian ligaments (both gubernaculum derivatives), epoophoron, paroophoron, Gartner duct, ureter, and the uterine artery/nerves/vein (lie at base of round ligament within the transverse cervical ligament
a double fold of parietal peritoneum divided into the mesosalphinx (uterine tubes), mesovarium (ovary), mesometrium (uterus), and the suspensory ligament of the ovary.
1) epoophoron

2) paroophoron

3) Gartner duct
1) mesonephric tubules derivative

2) mesonephric tubules derivative

3) mesonephric duct derivative
Anterior tibial artery

gives off the anterior tibial recurrent, medial and lateral malleolar arteries, dorsalis pedis artery (lies between the extensor hallucis longus and extensor digitorum longus)
1) descends on the anterior surface of the interosseus membrane with the deep fibular nerve (terminates as the dorsalis pedis)
dorsalis pedis artery
gives off: 1) lateral tarsal artery, 2) arcuate artery (gives off the metatarsal arteries), 3) first dorsal metatarsal artery, 4) deep plantar artery (enters the sole of the foot and joins the lateral plantar artery to form the plantar arch
Posterior tibial artery gives off the following branches:

note: passes behind the medial malleolus with the tibial nerve, where an ankle pulse can be palpated.
1) fibular artery (passes behind lateral malleolus), 2) medial plantar artery (superficial and deep branches), 3) lateral plantar artery (forms plantar arch with deep plantar artery - also gives off the plantar digital arteries
1) Placement of ligatures in the leg

2) acute arterial occlusion of the leg
1) the femoral artery can be ligated anywhere along its course, but collateral circulation is not as robust as in the upper limbs.

2) occlusion occurs most frequently where the femoral artery gives off the profunda femoris artery
metastasis of cancer of scrotum vs. testes
cancer of the scrotum will metastasize to superficial inguinal nodes; cancer of the testes will metastasize to deep lumbar nodes
vasectomy layers

**note that the tunica vaginalis is not cut, as it is present only over the anterior aspect of the testes
skin --> colle's fascia and dartos muscle --> external spermatic fascia --> cremasteric fascia and muscle --> internal spermatic fascia --> extraperitoneal fat
cremasteric reflex

**different afferent and efferent limbs!
stroking the skin of the superior and medial thigh stimulates sensory fibers that run with the ilioinguinal nerve (afferent limb). Motor fibers that run with the genital branch of the genitofemoral nerve are distributed to the cremasteric muscle (efferent limb).
Herniated disk between:
1) C4 and C5

2) C5 and C6
1) compresses C5: affects deltoid (axillary nerve); reduced biceps jerk; dermatome (sensory) lost on shoulder
2) lose C6; affects biceps/brachialis; lose flexion and supination of forearm; lose musculocutaneous nerve, reduced biceps and brachioradialis jerk; sensation loss on thumb
Herniation between:
1) C6 and C7

2) L3 and L4
1) lose C7 dermatome (middle/index finger); lose radial nerve - reduced triceps jerk, triceps and wrist extensors lost

2) Lose L4 dermatome - medial surface of leg and big toe; lose femoral nerve - weak quads, reduced knee jerk.
Herniation between:
1) L4 and L5

2) L5 and S1
1) lose L5; lateral surface of leg and dorsum of foot; lose common fibular nerve - weakness of dorsiflexion and extension of toes

2) lose S1 - posterior surface of lower limb and little toe; lose tibial nerve - reduced ankle jerk and plantarflexion. lose the gastroc and soleus
jejunum vs. ileum

both have villi and crypts (vs. large intestine, where you see Taeniae coli, appendices epiploicae, and haustra (sacculations of the wall))
jejunum: >3cm diameter, large circular folds of mucosa and submucosa (plicae circularis), long vasa recta, main site of nutrient absorption, thicker wall

ileum: <3cm, few plicae circularis, short vasa recta, B12 and H2O absorption, bile recirculation
Familial adenomatous polyposis (FAP)
especially rectosigmoid colon. Autosomal dominant, mutation in APC anti-oncogene. Progression from small to large polyp involves mutation in ras proto-oncogene. progression to metastasis is associated with mutations in DCC and p53 anti-oncogenes
hormone levels in:

congenital adrenal hyperplasia

addison disease

secondary adrenal insufficiency
CAH: aldo, cortisol low; androgens and ACTH high

Addison's: aldo, cortisol, androgens low; ACTH high

secondary adrenal insufficiency: aldosterone NORMAL, cortisol, androgens and ACTH low
overview of the innervation of the GI tract
The GI tract is innervated by the celiac plexus, superior mesenteric plexus, inferior mesenteric plexus, and superior hypogastric plexus, which are located around the abdominal aorta and contain both parasympathetic (vagus nerve and pelvic splanchnics) and sympathetic components
Parasympathetic nervous system in the gut:
1) motor component
2) sensory component

*note: reflexes in which both the motor and sensory components travel in CN X are called vasovagal.
1) preganglionic neurons are located in the dorsal nucleus of the vagus and the nucleus ambiguus in the medulla or in the grey matter of S2-S4.

2) neurons are located in the nodose (inferior) ganglion of CN X and the dorsal root ganglia of S2-S4. Carries all visceral sensation EXCEPT FOR PAIN!
Sympathetic nervous system effects in the gut
preganglionic neurons live in the intermediolateral cell column of T5-L2; preganglionic axons travel in the greater, lesser, least, and lumbar splanchnic nerves and synapse in ganglia along the aorta. Postganglionic neurons synapse in the enteric nervous system, control GI blood flow, and carry visceral PAIN.
annular pancreas
ventral pancreatic bud fuses with the dorsal bud BOTH dorsally and ventrally, forming a ring around the duodenum, causing duodenal obstruction noticed after birth by bilious vomiting. XR shows "double bubble" sign due to dilation of the stomach and distal duodenum
1) neurocranium

2) viscerocranium
1) frontal, occipital, ethmoid, sphenoid, parietal, temporal bones

2) bones of the face - develop from pharyngeal arches
sutures
5 sutures: frontal, sagittal, lambdoid, coronal, and squamous

**molding (deformation of skull at birth) may exert enough tension to rupture the great cerebral vein (of Galen)!
fontanelles
fontanelles are large fibrous areas where several sutures meet.

The anterior fontanelle may even be used to obtain a blood sample from the underlying superior sagittal sinus!
SCALP components
S: skin
C: connective tissue
A: aponeurosis (attachment for orbitofrontalis muscle, temporoparietalis, and superior auricular muscle
L: Loose areolar tissue
P: Pericranium (periosteum
Dural infolding or reflections

**vascular supply of dura is by middle meningeal artery; venous drainage is by middle meningeal veins --> pterygoid plexus. Innervation of dura is by branches from CN V1, V2, V3, and sensory fibers that travel with CN X and XII
a. falx cerebri (contains inferior and superior sagittal sinus)
b. falx cerebelli
c. tentorium cerebelli (encloses transverse and superior petrosal sinuses)
d. diaphragma sellae
bony orbit
roof: frontal bone, lesser wing of sphenoid. medial: ethmoid and lacrimal bones. lateral: zygomatic and greater wing of sphenoid bone. floor: maxilla and palatine bone.
1) superior orbital fissue

2) inferior orbital fissure

*note: the optic canal transmits CN II but also the opthalmic artery! (branch of the internal carotid)
1) formed by a gap between greater and lesser wings of sphenoid; communicates with middle cranial fossa. contains CN III, IV, V1, VI, and the opthalmic vein.

2) formed by a gap between the greater wing of the sphenoid and the maxillary bone; communicates with the infratemporal fossa and the pterygopalatine fossa. contains the infraorbital nerve (from V2), infraorbital artery, and inferior opthalmic vein.
Eyelid
the interior surface of the eyelid is a mucous membrane called the palpebral conjunctiva. it is reflected onto the eyeball, where it is called the bulbar conjunctiva. this is continuous with the corneal epithelium.
3 important muscles associated with the eyelid:

1) levator palpebrae superioris
2) superior tarsal muscle
3) orbicularis oculi
1) skeletal muscle innervated by CN III

2) smooth muscle innervated by postganglionic sympathetic neurons. Minor player in keeping the eye open.

3. skeletal muscle innervated by CN VII; closes the eye.
Lacrimal gland: products and innervation
makes lysozyme, IgA, and lactoferrin (sequesters iron). Preganglionic neuronal cell bodies live in the superior salivatory and lacrimal nuclei, and axons run with CN VII (via the nervus intermedius, greater petrosal n., and the nerve of the pterygoid canal) and enter the pterygopalatine ganglion. Postganglionic neurons run with the zygomaticofacial branch of V2 and the lacrimal branch of V1.
Thyroid gland blood supply

**Note: the arterial supply of the superior and inferior parathyroid glands is from the INFERIOR thyroid artery!
supplied by external carotid via the superior thyroid artery, and the subclavian-thyrocervical trunk via the inferior thyroid artery. Veins dump into the interna ljugular. The laryngeal nerves run in the tracheoesophageal groove along the posterior surface of the thyroid.
Parotid gland innervation

**ANTI-muscarinics cause dry mouth!
sympathetics from the superior cervical ganglion stimulate a thick mucous secretion and vasoconstriction (dry mouth). parasympathetics start in the inferior salivatory nucleus of CN IX, and travel with the tympanic nerve and lesser petrosal nerve on their way to the otic ganglion. postganglionic PNS nerves travel with the auriculotemporal nerve of CN V to stimulate a watery secretion.
complications of parotid surgery
may damage the auriculotemporal nerve of CN V, causing loss of sensation in the auriculotemporal region of the head. Because the auriculotemporal nerve also carries sympathetic fibers to sweat glands, damage to the nerve may result in aberrant regeneration leading to a person sweating upon eating! (Frey's syndrome)
facial laceration near the anterior border of the masseter
will cut the parotid duct and the buccal branch of CN VII.