Soriano Notes~Chapter 7~Anatomy & Physiology

Front 1

*Axial Skeleton

Back 1

~80 bones segregated into 3 regions
a)Skull
b)Vertebral column
c)Bony thorax

Front 2

The Skull

Back 2

1~Skull body’s most complex bony structure is formed by cranium & facial bones

2~Cranium – protects brain & is site of attachment for head & neck muscles

3~Facial bones:
a)Supply framework of face, sense organs & teeth
b)Provide openings for passage of air & food
c)Anchor facial muscles of expression

Front 3

Anatomy of Cranium

Back 3

1~8 cranial bones -2 parietal, 2 temporal, frontal, occipital, sphenoid & ethmoid

2~Cranial bones are thin & remarkably strong for their weight

Front 4

Frontal Bone

Back 4

1~Forms anterior portion of cranium

2~Articulates posteriorly w parietal bones via coronal suture

3~Major markings include supraorbital margins, anterior cranial fossa & frontal sinuses (internal & lateral to glabella)

Front 5

Parietal Bones & Major Associated Sutures

Back 5

1~Form most of superior & lateral aspects of skull

2~4 sutures mark articulations of parietal bones
a)Coronal suture –Articulation between parietal bones & frontal bone anteriorly
b)Sagittal suture –Where right & left parietal bones meet superiorly
c)Lambdoid suture –Where parietal bones meet occipital bone posteriorly
d)Squamosal or squamous suture –Where parietal & temporal bones meet

Front 6

Occipital Bone & Its Major Markings

Back 6

1~Forms most of skull’s posterior wall & base

2~Major markings include posterior cranial fossa, foramen magnum, occipital condyles & hypoglossal canal

Front 7

Temporal Bones

Back 7

~Form inferolateral aspects of skull & parts of cranial floor

~Divided into 4 major regions –Squamous, tympanic, mastoid & petrous

~Major markings include zygomatic, styloid & mastoid processes & mandibular & middle cranial fossae

~Major openings include stylomastoid & jugular foramina, external & internal auditory meatuses & carotid canal

Front 8

Sphenoid Bone

Back 8

~Butterfly-shaped bone that spans width of middle cranial fossa

~Forms central wedge that articulates w all other cranial bones

~Consists of a central body, greater wings, lesser wings & pterygoid processes

~Major markings: Sella turcica, hypophyseal fossa & pterygoid processes

~Major openings include foramina rotundum, ovale & spinosum; optic canals; & superior orbital fissure

Front 9

Ethmoid Bone

Back 9

~Most deep of skull bones; lies between sphenoid & nasal bones

~Forms most of bony area between nasal cavity & orbits

~Major markings include cribriform plate, crista galli, perpendicular plate, nasal conchae & ethmoid sinuses

Front 10

Wormian Bones

Back 10

~Tiny irregularly shaped bones that appear within sutures

Front 11

Facial Bones

Back 11

~Fourteen bones of which only mandible & vomer are unpaired

~Paired bones are maxillae, zygomatics, nasals, lacrimals, palatines & inferior conchae

Front 12

Mandible & Its Markings

Back 12

~Mandible (lower jawbone) is largest, strongest bone of face

~Its major markings include coronoid process, mandibular condyle, alveolar margin & mandibular & mental foramina

Front 13

Maxillary Bones

Back 13

~Medially fused bones that make up upper jaw & central portion of facial skeleton

~Facial keystone bones that articulate with all other facial bones except mandible

~Their major markings include palatine, frontal & zygomatic processes, alveolar margins, inferior orbital fissure & maxillary sinuses

Front 14

Zygomatic Bones

Back 14

~Irregularly shaped bones (cheekbones) that form prominences of cheeks & inferolateral margins of orbits

Front 15

Other Facial Bones

Back 15

~Nasal bones –Thin medially fused bones that form bridge of nose

~Lacrimal bones –Contribute to medial walls of orbit & contain a deep groove called lacrimal fossa that houses lacrimal sac

~Palatine bones –2 bone plates that form portions of hard palate, posterolateral walls of nasal cavity & a small part of orbits

~Vomer –Plow-shaped bone that forms part of nasal septum

~Inferior nasal conchae –Paired, curved bones in nasal cavity that form part of lateral walls of nasal cavity

Front 16

Orbits

Back 16

~Bony cavities in which eyes are firmly encased & cushioned by fatty tissue

~Formed by parts of 7 bones – frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal & ethmoid

Front 17

Nasal Cavity

Back 17

~Constructed of bone & hyaline cartilage

~Roof – formed by cribriform plate of ethmoid

~Lateral walls – formed by superior & middle conchae of ethmoid, perpendicular plate of palatine & inferior nasal conchae

~Floor – formed by palatine process of maxillae & palatine bone

Front 18

Paranasal Sinuses

Back 18

~Mucosa-lined, air-filled sacs found in 5 skull bones –Frontal, sphenoid, ethmoid & paired maxillary bones

~Air enters paranasal sinuses from nasal cavity & mucus drains into nasal cavity from sinuses

~Lighten the skull & enhance resonance of voice

Front 19

Hyoid Bone

Back 19

~Not actually part of skull but lies just inferior to mandible in anterior neck

~Only bone of body that does not articulate directly w another bone

~Attachment point for neck muscles that raise & lower larynx during swallowing
& speech

Front 20

*Vertebral Column

Back 20

~Formed from 26 irregular bones (vertebrae) connected in such a way that a flexible curved structure results:

1~Cervical vertebrae – 7 bones of neck

2~Thoracic vertebrae – 12 bones of torso

3~Lumbar vertebrae – 5 bones of lower back

4~Sacrum – bone inferior to lumbar vertebrae that articulates w hip bones

Front 21

*Vertebral Column: Curvatures

Back 21

1~Posteriorly concave curvatures –Cervical & lumbar

2~Posteriorly convex curvatures –Thoracic & sacral

~Abnormal spine curvatures include scoliosis (abnormal lateral curve), kyphosis (hunchback) & lordosis (swayback)

Front 22

Vertebral Column: Ligaments

Back 22

~Anterior & posterior longitudinal ligaments –Continuous bands down front & back of spine from neck to sacrum

~Short ligaments connect adjoining vertebrae together

Front 23

Vertebral Column: Intervertebral Discs

Back 23

~Cushion-like pad composed of 2 parts:
1~Nucleus pulposus –Inner gelatinous nucleus that gives disc its elasticity & compressibility
2~Annulus fibrosus – surrounds nucleus pulposus w a collar composed of collagen & fibrocartilage

Front 24

General Structure of Vertebrae

Back 24

~Body or centrum –Disc-shaped, weight-bearing region

~Vertebral arch –Composed of pedicles & laminae that, along w centrum, enclose vertebral foramen

~Vertebral foramina –Make up vertebral canal through which spinal cord passes

~Spinous processes project posteriorly & transverse processes project laterally

~Superior & inferior articular processes –Protrude superiorly & inferiorly from pedicle-lamina junctions

~Intervertebral foramina – Lateral openings formed from notched areas on superior & inferior borders of adjacent pedicles

Front 25

Cervical Vertebrae

Back 25

~7 vertebrae (C1-C7) are smallest, lightest vertebrae

~C3-C7 are distinguished w an oval body, short spinous processes & large, triangular vertebral foramina

~Each transverse process contains a transverse foramen

Front 26

Cervical Vertebrae: Atlas (C1)

Back 26

~No body nor a spinous process

~Consists of anterior & posterior arches & 2 lateral masses

~Superior surfaces of lateral masses articulate w occipital condyles

Front 27

Cervical Vertebrae: Axis (C2)

Back 27

~Has a body, spine & vertebral arches as do other cervical vertebrae

~Has dens or odontoid process, which projects superiorly from body & is cradled in anterior arch of atlas

~Dens is a pivot for rotation of atlas

Front 28

*Regional Characteristics of Vertebrae:
Thoracic Vertebrae

Back 28

~12 vertebrae (T1-T12) all of which articulate w ribs

~Major markings include 2 facets & 2 demifacets on heart-shaped body, circular vertebral foramen, transverse processes & a long spinous process

~Location of articulate facets prevents flexion & extension, but allows rotation of this area of spine

Front 29

*Regional Characteristics of Vertebrae:
Lumbar Vertebrae

Back 29

~5 lumbar vertebrae (L1-L5) are located in small of back & have an enhanced weight-bearing function

~Have short, thick pedicles & laminae, flat hatchet-shaped spinous processes & a triangular-shaped vertebral foramen

~Orientation of articular facets locks lumbar vertebrae together to provide stability

Front 30

*Regional Characteristics of Vertebrae:
Sacrum

Back 30

~Consists of 5 fused vertebrae (S1-S5), which shape posterior wall of pelvis

~Articulates w L5 superiorly, & w auricular surfaces of hip bones

~Major markings include sacral promontory, transverse lines, alae, dorsal sacral foramina, sacral canal & sacral hiatus

Front 31

*Regional Characteristics of Vertebrae:
Coccyx (Tailbone)

Back 31

~Coccyx is made up of 4 (in some cases 3 to 5) fused vertebrae that articulate superiorly w sacrum

Front 32

Bony Thorax (Thoracic Cage)

Back 32

~Thoracic cage is composed of thoracic vertebrae dorsally, ribs laterally & sternum and costal cartilages anteriorly

~Functions:
a)Forms a protective cage around heart, lungs & great blood vessels
b)Supports shoulder girdles & upper limbs
c)Provides attachment for many neck, back, chest & shoulder muscles
d)Uses intercostal muscles to lift & depress thorax during breathing

Front 33

Sternum

Back 33

(Breastbone)

~A dagger-shaped, flat bone that lies in anterior midline of thorax

~Results from fusion of 3 bones

–Superior manubrium, body & inferior xiphoid process

~Anatomical landmarks include jugular (suprasternal) notch, sternal angle & xiphisternal joint

Front 34

*Ribs

Back 34

~12 pair of ribs form sides of thoracic cage
~All ribs attach posteriorly to thoracic vertebrae
~Superior 7 pair (true, or vertebrosternal ribs) attach directly to sternum via costal cartilages
~Ribs 8-10 (false, or vertebrocondral ribs) attach indirectly to sternum via costal cartilage
~Ribs 11-12 (floating or vertebral ribs) have no anterior attachment

Front 35

Structure of a Typical True Rib

Back 35

~Bowed, flat bone consisting of a head, neck, tubercle & shaft

Front 36

*Appendicular Skeleton

Back 36

~Made up of bones of limbs & their girdles

~Pectoral girdles attach upper limbs to body trunk

~Pelvic girdle secures lower limbs

Front 37

*Pectoral Girdles

Back 37

(Shoulder Girdles)

~Consist of anterior clavicles & posterior scapulae

~They attach upper limbs to axial skeleton in a manner that allows for maximum movement

~They provide attachment points for muscles that move upper limbs

Front 38

Clavicles (Collarbones)

Back 38

~Slender, doubly curved long bones lying across superior thorax

~Acromial (lateral) end articulates w scapula & sternal (medial) end articulates w sternum

~Provide attachment points for numerous muscles & act as braces to hold scapulae & arms out laterally away from body

Front 39

Scapulae

Back 39

(Shoulder Blades)

~Triangular, flat bones lying on dorsal surface of rib cage, between second (Shoulder Blades) 7th ribs

~Scapulae have 3 borders & 3 angles

~Major markings include suprascapular notch, supraspinous & infraspinous fossae, spine, acromion & coracoid process

Front 40

Upper Limb

Back 40

~Consists of arm (brachium), forearm (antebrachium) & hand (manus)

~37 bones form skeletal framework of each upper limb

Front 41

Arm

Back 41

~Humerus is sole bone of arm

~It articulates w scapula @ shoulder & radius and ulna @ elbow

~Major markings:
1~Proximal humerus includes head, anatomical & surgical necks, greater & lesser tubercles & intertubercular groove
2~Distal humerus includes capitulum, trochlea, medial & lateral epicondyles & coronoid and olecranon fossae
3~Medial portion includes radial groove & deltoid process

Front 42

*Forearm

Back 42

~Bones of forearm are radius & ulna

~They articulate proximally w humerus & distally w wrist bones

~They also articulate w each other proximally & distally at small radioulnar joints

~Interosseous membrane connects 2 bones along their entire length

Front 43

*Bones of Forearm:
Ulna

Back 43

~Lies medially in forearm & is slightly longer than radius

~Forms major portion of elbow joint with humerus

~Its major markings include olecranon, coronoid process, trochlear notch, radial notch, & styloid process

Front 44

*Bones of Forearm:
Radius

Back 44

~Lies opposite (lateral to) ulna & is thin at its proximal end, widened distally

~Superior surface of head articulates w capitulum of humerus

~Medially, head articulates w radial notch of ulna

~Major markings include radial tuberosity, ulnar notch, & styloid process

Front 45

Hand

Back 45

~Skeleton of hand contains wrist bones (carpals), bones of palm (metacarpals) & bones of fingers (phalanges)

Front 46

Carpus (Wrist)

Back 46

~8 bones:
a)Scaphoid, lunate, triquetral & pisiform proximally
b)Trapezium, trapezoid, capitate & hamate distally

Front 47

Metacarpus (Palm)

Back 47

~5 numbered (1-5) metacarpal bones radiate from wrist to form palm
a)Their bases articulate w carpals proximally & w each other medially & laterally
b)Heads articulate w phalanges

Front 48

Phalanges

Back 48

(Fingers)

~14 miniature long bones in each hand

~Fingers (digits) are numbered 1-5, beginning w thumb (pollex)

~Each finger (except thumb) has 3 phalanges –Distal, middle & proximal

~Thumb has no middle phalanx

Front 49

*Pelvic Girdle

Back 49

~Hip is formed by a pair of hip bones (os coxae or coxal)

~Together w sacrum & coccyx, these bones form bony pelvis

~Pelvis:
a)Attaches lower limbs to axial skeleton w strongest ligaments of body
b)Transmits weight of upper body to lower limbs
c)Supports visceral organs of pelvis

Front 50

Ilium

Back 50

~Large flaring bone that forms superior region of coxal bone

~Consists of a body & a superior winglike portion called Ala

~Broad posterolateral surface is called gluteal surface

~Auricular surface articulates w sacrum (sacroiliac joint)

~Major markings include iliac crests, 4 spines, greater sciatic notch, iliac fossa, arcuate line & pelvic brim

Front 51

Ischium

Back 51

~Forms posteroinferior part of hip bone

~Thick body articulates w ilium & thinner ramus articulates w pubis

~Major markings include ischial spine, lesser sciatic notch & ischial tuberosity

Front 52

Pubis

Back 52

~Forms anterior portion of hip bone

~It articulates w ischium & ilium

~Major markings include superior& inferior rami, pubic crest, pubic tubercle, pubic arch, pubic symphysis & obturator foramen (along w ilium & ischium)

Front 53

Comparison of Male & Female Pelvic Structure

Back 53

1~Female pelvis
a)Tilted forward, adapted for childbearing
b)True pelvis defines birth canal
c)Cavity of true pelvis is broad, shallow & has greater capacity

2~Male pelvis
a)Tilted less forward
b)Adapted for support of heavier male build & stronger muscles
c)Cavity of true pelvis is narrow & deep

Front 54

The Lower Limb

Back 54

~3 segments of lower limb are thigh, leg & foot

~They carry weight of erect body & are subjected to exceptional forces when one jumps or runs

Front 55

*Femur

Back 55

~Sole bone of thigh, largest & strongest bone in body

~It articulates proximally w hip & distally w tibia & fibula

~Major markings include head, fovea capitis, greater lesser trochanters, gluteal tuberosity, lateral & medial condyles & epicondyles, linea aspera, patellar surface & intercondylar notch

Front 56

Leg

Back 56

~Tibia & fibula form skeleton of leg

~They are connected to each other by interosseous membrane

~They articulate w femur proximally & w ankle bones distally

~They also articulate w each other via immovable tibiofibular joints

Front 57

*Tibia

Back 57

~Receives weight of body from femur & transmits it to foot

~Major markings include medial & lateral condyles, intercondylar eminence, tibial tuberosity, anterior crest, medial malleolus & fibular notch

Front 58

*Fibula

Back 58

~Sticklike bone w slightly expanded ends located laterally to tibia

~Major markings include head & lateral malleolus

Front 59

Foot

Back 59

~Skeleton of foot includes tarsus, metatarsus & phalanges (toes)

~Supports body weight & acts as a lever to propel body forward in walking & running

Front 60

Tarsus

Back 60

~Composed of 7 bones that form posterior half of foot

~Body weight is carried primarily on talus & calcaneus

~Talus articulates w tibia & fibula superiorly & calcaneus inferiorly

~Other tarsus bones include cuboid and navicular & medial, intermediate & lateral cuneiforms

Front 61

Calcaneus

Back 61

~Forms heel of foot

~Carries talus on its superior surface

~Point of attachment for calcaneal (Achilles) tendon of calf muscles

Front 62

Metatarsus & Phalanges

Back 62

1~Metatarsals:
a) (1-5) long bones that articulate w proximal phalanges
b)Enlarged head of metatarsal 1 forms “ball of foot”

2~Phalanges
a)14 bones of toes
b)Each digit has 3 phalanges except hallux, which has no middle phalanx

Front 63

Arches of Foot

Back 63

~3 arches maintained by interlocking foot bones & strong ligaments

~Allow foot to hold up weight

~Arches are:
1~Lateral longitudinal –Cuboid is keystone of this arch
2~Medial longitudinal –Talus is keystone of this arch
3~Transverse –Runs obliquely from one side of foot to the other

Front 64

Developmental Aspects: Fetal Skull

Back 64

~Infant skull has more bones than adult skull

~At birth, fetal skull bones are incomplete & connected by fontanels

~Fontanels:
a)Unossified remnants of fibrous membranes between fetal skull bones
b)4 fontanels are anterior, posterior, mastoid & sphenoid

~Skull bones such as mandible & maxilla are unfused

Front 65

Developmental Aspects: Growth Rates

Back 65

~At birth, cranium is huge relative to face

~Mandible & maxilla are foreshortened but lengthen with age

~The arms & legs grow at a faster rate than head & trunk, leading to adult proportions

Front 66

Developmental Aspects: Spinal Curvature

Back 66

~Only thoracic & sacral curvatures are present at birth

~Primary curvatures are convex posteriorly, causing infant spine to arch like a 4-legged animal

~Secondary curvatures –Cervical & lumbar –Are convex anteriorly & are associated w child’s development

Front 67

Developmental Aspects: Old Age

Back 67

~Intervertebral discs become thin, less hydrated & less elastic

~Risk of disc herniation increases

~Loss of stature by several centimeters is common after age 55

~Costal cartilages ossify causing thorax to become rigid

~All bones lose mass