Anatomy Exam 5: Anterior Abdomen

Front 1

Obj.
Describe the location & basic organization of the abdomen

Back 1

Trunk btwn thorax (diaphram) & pelvis
Abdominal wall encloses abdominal cavity

Front 2

Obj.
Describe the skeletal support of the abdomen

Back 2

Abdominal wall proper:
-5 lumbar vertebrae posteriorly
-wings (alae) of ilia laterally
-diaphram superiorly
(right dome to 5th rib, left dome to 5th intercostal space)
-abdominal wall anteriorly

Front 3

Obj.
What are the implication of a high-arching respiratory diaphragm?

Back 3

The upper abdominal organs including the spleen & liver are protected by ribs

HOWEVER, if a rib is fractured, these organs can be injured

Front 4

Identify the following:
lumbar vertebrae
xiphoid process & body of sternum
lower ribs & costal cartilages
wing
illiac crest
ASIS
pubic crest
pubic tubercle
symphysis

Back 4

Front 5

Obj.
Describe the subdivision of the abdominal cavity into 4 quadrants for more precise localization's of organs or patients signs & symptoms

Back 5

lines: vertical & horizontal lines intersecting at the umbilicus

Front 6

Obj.
Describe the subdivision of the abdominal cavity into 9 regions for more precise localizations of organs or patients signs & symptoms

Back 6

lines: 2 vertical midclavicular planes
& two horizontal planes-
1. subcostal plane- through 10th costal cartilages
(or transpyloric plane)
2. transtubular plane- through the tubercles of the illiac crest (L5)

Front 7

What are the names of the 9 abdominal regions?

Back 7

Left and Right (6)
-Hypochondriac
-Lateral (flank)
-Inguinal
Midline (3)
-Epigastric
-Umbilical
-Hypogastric (pubic)

Front 8

What are Langer's lines (cleavage lines)?

Back 8

Lines of tension on the skin of the abdomen

-due to the arrangement of collagen fibers w/i the dermis

Front 9

What is the clinical significance of Langer's lines?

Back 9

Important for surgical incisions
*incisions made parallel to these lines will heal BEST!

-an incision made perpendicular is more likely to gap due to increasing tension, resulting in a longer healing time and more scar tissue

Front 10

Obj.
Describe the fasciae of the abdominal wall

Back 10

Above the umbilicus- single fatty layer
Below umbilicus- superficial fatty layer= Camper's, deeper membranous layer = Scarpa's

Front 11

Scarpa's fascia is continous with what 3 other fascias?

What is the clinical significance of this?

Back 11

continous with:
-superficial penile fascia
-dartos fascia (scrotum)
-Colle's fascia (perineum)

*Extravasated urine (or any infection) from a ruptured penile urethra may spread upward to the anterior abdominal wall (not downward bc scarpa fuses w/ fascia lata of thigh below inguinal)

Front 12

Obj.
Describe the innervation of the fascia

Back 12

Superficial fascia (anterolateral abdominal wall):
innervation: contains lateral & anterior cutaneous branches of the following;
-Thoracoabdominal nerves (T7-T11)
-T10 innervates umbilibus level
-Subcostal (T12)
-Illiohypogastric & ilioguinal nerves (L1)

Front 13

Obj.
Describe the blood supply of fascia

Back 13

Anterolateral Abdominal wall
Superficial vessels:
-superficial epigastric arteries
-superficial circumflex iliac arteries
Deep vessels:
-inferior epigastric artery
-superior epigastric artery
-deep circumflex iliac artery

Front 14

T/F
Disease of the lower thoracic wall (e.g. pleurisy of costal parietal pleura) may be referred to the abdomen

Back 14

TRUE

-lateral & anterior branches of the Thoracoabdominal nerves (T7-T11) originate from Intercostal nerves, thus leading to referred pain

Front 15

Where do the superficial epigastric & superficial circumflex iliac arteries originate from?

Back 15

femoral artery

Front 16

Where do the inferior epigastric and deep circumflex iliac arteries originate from?

Back 16

external iliac artery

Front 17

Where does the superior epigastric artery originate?

What does this artery anastomose with to provide a potential source for collateral circulation?

Back 17

internal thoracic artery

superior & inferior epigastric arteries anastomose as a potential source of collateral circulation

Front 18

Veins of the abdominal wall form collateral routes for return of blood to the heart if the _________ or __________________ is blocked.
What are these alternative routes termed?

Back 18

inferior or superior vena cava


"caval-caval shunts"

Front 19

What veins may anastamose to form this collateral circulation?

Back 19

The superficial epigastric vein (femoral)
& the lateral thoracic vein (axillary vein)
form the thoracoepigastric vein
OR
The inferior epigastric vein (external iliac)
& the superior epigastric vein (brachiocephalic)
within the rectus sheath

*not all people have this

Front 20

Describe the lymphatic drainage of the anterolateral abdominal wall

Back 20

above the umbilicus- superficial lymphatic vessels drain UPWARD to axillary lymph nodes

below the umbilicus- superficial lymphatic vessels drain DOWNWARD to superficial inguinal lymph nodes

*deep lymph vessels accompany deep veins

Front 21

Obj.
Describe the muscles of the abdominal wall

Back 21

Each side of the anteriolateral abdominal wall contains:
-external oblique
-internal oblique
-transversus abdominus
Each half contains:
rectus abdominis (enclosed by rectus sheath)

Front 22

Where do the 3 anteriolateral abdominal muscles develop from?

Back 22

from same 3 hypomeres as intercostal muscles

Front 23

Describe the orientation and location of the external oblique muscle

Back 23

-arises from lower 8 ribs & courses inferomedially
-posterior fibers insert into illiac crest & form external oblique aponeurosis (part of anterior rectus sheath)
-at midline aponeurotic fibers intersect from both sides (linea alba)
*most superior layer

Front 24

Describe the formation of the inguinal ligament

Back 24

between the anterior superior iliac spine & pubic tubercle, the external oblique aponeurosis has a rolled-under inferior free margin that forms the inguinal ligament

*spermatic cord lies w/i

Front 25

Describe the orientation and location of the internal oblique muscle

Back 25

-arises from the thoracolumbar fascia, iliac crest, & lateral 1/2 of inguinal ligament
-fibers course superiomedially at right angle to external oblique & continue into internal oblique aponeurosis
-medially splits around rectus abdominus & helps form anterior & posterior layers of rectus sheath above arcuate line
-fibers intersect at linea alba

Front 26

Describe the formation of the conjoint tendon (falx inguinalis)

Back 26

the most inferior fibers of the internal oblique joins the deeper transversus abdominus to form the conjoint tendon
-arches over spermatic cord/round ligament of uterus to attach to pubic crest & pecten pubic

Front 27

Describe the orientation & location of the transversus abdominis muscles

Back 27

-originates from costal cartilages 7-17, thoracolumbar fascia, iliac crest, & lateral 1/3 of inguinal ligament
-runs transversely
-lowest tendinous fibers arch downward to help form the conjoint tendon
-helps form posterior layer of recus sheath

Front 28

Describe the orientation & location of the rectus abdominis muscle

Back 28

-ascends vertically from pubic crest to cartilages 5-7
-3 or more tendinous intersections = 6 pack
-enclosed w/i connective rectus sheath (formed by aponeuroses of 3 flat abdominal muscles)
-is seperated at midline by linea alba
-laterally bound to linea semilunaris

Front 29

Describe the composition of the rectus sheath above & below arcuate line

Back 29

above:
internal oblique aponeruosis splitting to contribute to both anterior & posterior layers
below:
all 3 aponeurosis pass anterior to rectus abdominis, posterior surface contacts transversalis fascia

Front 30

Obj.
Describe the innervation & blood supply of the muscles of the abdominal wall

Back 30

**no major nerves of vessels cross linea alba

Front 31

Obj.
Describe the actions of the muscles of the abdominal wall

Back 31

-support & protect abdominal muscles
-relax during inhalation
-contract during forced exhalation
-increase intra-abdominal pressure (
-trunk movement

Front 32

Increasing intra-abdominal pressure is important for what (3)?

Back 32

- emptying bladder (micturation) & rectum (defecation)
- coughing & sneezing
- giving birth (parturition)

Front 33

Differentiate btwn guarding and rigidity of the abdominal muscles

Back 33

guarding- involuntary muscle spasms occur during palpation w/ cold hands (sensory response)

rigidity- involuntary spasm due to inflammation that irritates nerve supply (appendicitis, etc)

Front 34

Describe the mechanism of trunk movement by the abdominal muscles

Back 34

bilateral contraction= flexion of trunk
unilateral contraction= lateral flexion of trunk (ipsilateral)
contralateral flexion of internal & external oblique= flexion & rotation of trunk to side of internal oblique

Front 35

Obj.
Describe anatomy of the inguinal region

Back 35

area of weakness w/i the inferior part of anterolateral abdominal wall
-contains the inguinal canal, which transmits the large spermatic cord in males & small thin round ligament of uterus in females

Front 36

Describe the location of the inguinal canal

Back 36

-oblique passage through the abdominal wall
-extends inferomedially from deep inguinal ring (outpouch of transversalic fascia) to the superficial inguinal ring (w/i external oblique aponeurosis)
-lies superior to medial half of inguinal ligament

Front 37

Boundaries of inguinal canal

Back 37

anterior wall: external oblique aponeurosis, reinforced laterally by internal oblique aponeurosis
posterior wall: transversalic fascia, reinforced by conjoint tendon
roof: arching fibers of internal oblique & transversus abdominis
floor: inguinal ligament reinforced medially by lacunar ligament

Front 38

Obj.
How does the anatomy of the inguinal region predispose it to the development of inguinal hernias?

Back 38

Protrusion of viscera from abdominal cavity through the inguinal region account for 75% of hernias
-may follow path of descent of testis, leaves abdominal cavity lateral to the inferior epigastric artery, through superficial inguinal ring (indirect, most common)
-may push directly into inguinal triangle within canal, through a weak conjoint tendon of abdominal wall medial to inferior epigastric artery (direct)

Front 39

Obj.
Describe the different types of abdominal hernias

Back 39

congenital/acquired
inguinal/umbilical/epigastric
external hernia= defect in the abdominal wall
internal hernia= defect through internal opening

Front 40

An indirect inguinal hernia has three fascial coverings of the spermatic cord, what are they?

Back 40

-internal spermatic fascia (from transversalis fascia)
-cremasteric fascia (from internal oblique)
-external spermatic fascia (from external oblique aponeurosis)

Front 41

Is an indirect inguinal hernia congenital or aquired?

Back 41

congenital, represents a persisten processus vaginalis
or in women as a persistant peritoneal pouch = canal of Nuck

Front 42

An indirect hernia can be palpated at the superficial inguinal ring. Why would is it necessary to repair this hernia surgically?

Back 42

It is at significant risk of becoming entrapped (incarceration) w/ bowel obstruction & possible loss of blood supply (strangulation)

Front 43

What type of inguinal hernia is more likely to descend into the scrotum?

Back 43

INDIRECT inguinal hernia

Front 44

What structures form the inguinal (Hesselbach's) triangle (where direct inguinal hernias protrude)?

Back 44

laterally- inferior epigastric artery
medially- rectus abdominus
inferiorly- inguinal ligament, reinforced posteriorly by iliopubic tract (transversalic fascia)

Front 45

What are the 2 fascial coverings of a direct inguinal hernia?

Back 45

hernial sac- transversalis fascia
outer covering- external spermatic fascia

*protrudes through superficial inguinal ring

Front 46

In a healthy patient, what factors prevent formation of inguinal hernias?

Back 46

-contraction of internal oblique & transversus abdominis muscle fibers
-pressure of the posterior wall of the inguinal canal toward the anterior wall
-location of the conjoint tendon

Front 47

Umbilical hernias are most common in _____________ because the anterior abdomen is relatively weak at the umbilical ring. Often resolve, but may be severe congenital hernias such as ______________ or ____________

Back 47

newborns


omphalocele (covered by amnion) or gastroschisis (not covered by amnion)

Front 48

What causes incisional hernias?

Back 48

protrusions of omentum or organs through sites of surgical incision
-result of improper healing or muscle weakness due to loss of innervation