APPENDICULAR SKELTON

Pectoral girdle

1. Clavicles – collar bones

-a. Sternal end – medial; cone shaped; articulates with manubrium of sternum

-b. Acromial end – lateral; articulates with scapula

2. Scapula – shoulder blade

-a. Acromion – articulates with acromial end of clavicle

-b. Coracoid process – anterior process; helps anchor biceps muscle to arm

-c. Glenoid cavity (fossa) – articulates with the humerus; shoulder joint

-d. Spine – posterior; terminates laterally as acromion

-e. Borders – 3; medial, lateral and superior

-f. Angles – superior (superior and medial borders meet); inferior (medial meets lateral)

Upper limb: arm (humerus)

1. Head – semi-hemispherical; articulates with glenoid cavity of scapula

2. Anatomical neck – inferior to head; slight constriction

3. Greater tubercle – more lateral process; muscle attachment

4. Lesser tubercle – more medial; muscle attachment

5. Intertubercular groove – tendon of biceps muscle

6. Surgical neck – just distal to tubercles; site of breaks

7. Deltoid tuberosity – midway down; lateral side; v-shaped; deltoid muscle attaches

8. Radial groove – posterior; oblique; radial nerve groove

9. Trochlea – distal condyle; more medial; hourglass; articulates with ulna

10. Capitulum – distal condyle; more lateral; ball shaped; articulates with radius

11. Epicondyles – just above condyles above; medial and lateral; muscle attachment

12. Coronoid fossa – anterior; receives coronoid process of ulna

13. Olecranon fossa – posterior; receives the olecranon process of ulna

Upper limb: forearm

1. Ulna – larger; mostly forms elbow; most medial

-a. Olecranon process – proximal posterior process; elbow; into fossa

-b. Coranoid process – proximal anterior process; into fossa

-c. Trochlear notch – concavity between the two processes; over trochlea

-d. Radial notch – ulna articulates with head of the radius

-e. Head – knob like narrowed shaft; distally; little role in hand movement

-f. Styloid process – medial to head; ligament to wrist

2. Radius – smaller; distal end concave; mostly articulates with hand; most lateral

-a. Head – proximal; concave surface; articulates with capitulum of ulna

-b. Radial tuberosity – rough process just distal to head; biceps insertion

-c. Ulnar notch – distal, medial; expanded radius; articulates with the head of the ulna

-d. Styloid process – ligaments which run to the wrist

3. Interosseous membrane – connects the ulna and radius

Upper limb: hand

1. Carpus (wrist) – 8 small short bones; Sally left the party to take Cathy home

-a. Scaphoid – articulates with radius; first row; most lateral

-b. Lunate – articulates with the radius; just medial to scaphoid

-c. Triquentrum – first row

-d. Pisiform – first row

-e. Trapezium – second row; most lateral

-f. Trapezoid – second row; just medial to trapezoid

-g. Capitate – second row

-h. Hamate – second row

2. Metacarpus – palm; metacarpals; numbered from lateral (1) to medial (5)

3. Phalanges – finger bones

-a. Thumb – 1^st proximal and 1^st distal phalanx

-b. Fingers – proximal, middle, and distal; 2 to 5, most lateral to medial

Pelvic girdle

1. Coxal – hip bones; articulate with each other anterior; with sacrum posterior

2. Bony pelvis – the two coxal bones and the sacrum

3. Acetabulum – fusion of three bones that make up the coxal bone; hip joint

4. Ilium – large flaring bone forms the superior part of the coxal bone

-a. Ala – superior winged portion

-b. Iliac crest – thickened superior margin

-c. Anterior superior iliac spine – blunt, anterior end of iliac crest

-d. Posterior superior iliac spine – sharp, posterior end of iliac crest

-e. Anterior inferior iliac spine – less prominent, located below anterior superior

-f. Posterior inferior iliac spine – less prominent, located below posterior superior

-g. Greater sciatic notch – indentation inferior to posterior inferior; sciatic nerve to thigh

-h. Auricular surface – forms sacroiliac joint; auricular surface of sacrum

-i. Arcuate line – anteriorly and inferiorly from auricular surface

5. Ischium – posterioinferior part of coxal bone; arch shaped

-a. Ischial body – joins ilium

-b. Ischial ramus – joins pubis

-c. Ischial spine – projects medially; ligament attached to sacrum

-d. Lesser sciatic notch – inferior to ischial spine; nerves and blood vessels

-e. Ishial tuberiosity – inferior surface of ischial body; rough, thick, weight of body

6. Pubis – anterior portion of hip bone; V-shaped

-a. Pubic body – lies medially

-b. Superior pubic ramus – superior from body to ilium

-c. Inferior pubic ramus – inferior from body to ischium

-d. Pubic crest – thickened anterior border of pubic body

-e. Pubic tubercle – lateral end of pubic crest; attachment to inguinal ligament

-f. Obturator foramen – pubic rami, ishium; fibrous membrane; few vessels and nerve

-g. Pubic symphysis – pubic bodies join; fibrocartilage disc

Pelvic girdle: sex differences

1. Child birth – differences in pelvic inlet and outlet for childbirth

2. Pubic arch – angle between 2 pubic bones and symphysis

-a. Males – more acute; 50 to 60^◦

-b. Females – more rounded; 80 to 90^◦

3. Pelvic brim – continuous oval ridge; pubic crest; arcuate line; sacral promontory

4. False pelvis – superior to pelvic brim; alae laterally and lumbar vertebrae posterior

5. True pelvis – inferior to pelvic brim

6. Pelvic inlet – pelvic brim

-a. Males – narrow; heart shaped

-b. Females – wider; oval from side to side

7. Pelvic outlet – pubic arch; ischia; sacrum and coccyx

-a. Males – Narrow; ischial tuberosity pointed more medially

-b. Females – wider; ischial tuberosity shorter

8. Sacrum – part of the bony pelvis; revisited

-a. Males – narrow; longer

-b. Female – shorter; curvature accentuated

9. Coccyx – also part of bony pelvis

-a. Males – less movable; curves ventrally

-b. Females – movable; straighter

Lower limb: thigh

1. Femur – single bone of thigh; largest bone of the body

2. Head – ball lake; into acetabulum

3. Fovea capitis – central pit in head

4. Neck – carries the head; angles laterally to join shaft

5 Greater trochanter – junction neck and shaft; lateral; muscle attachment

6. Lesser trochanter – junction neck and shaft; posteriomedial; muscle attachment

7. Intertrochanteric line – anterior between trochanter

8. Intertrochanteric crest – posterior between trochanter

9. Gluteal tuberosity – inferior to intertrochanteric crest; muscles

10. Linea aspera – long vertical posterior line; from above; muscles

11. Condyles – distal; wheel like; lateral and medial

12. Epicondyles – superior to condyles; muscle attachment

13. Patellar surface – anterior; between condyles

14. Patella – triangle sesamoid bone; quadriceps tendon; protects knee

Lower limb: leg

1. Interosseous membrane – connects the two bones

2. Tibiofibular joints – both distal and proximal

3. Tibia – weight of body; more medial

-a. Condyles – medial and lateral; proximal; concave

-b. Tibial tuberosity – anterior; patellar ligament attaches

-c. Medial malleolus – medial bulge of ankle

-d. Fibular notch – participates in distal tibiofibular joint

4. Fibula – stick like; lateral; no weight; muscle attachment

-a. Head – proximal end

-b. Lateral malleolus – lateral bulge of ankle

Lower limb: foot

1. Tarsus – tarsal bones; posterior half of foot

-a. Talus – articulates with tibia and fibula; anteriorly

-b. Calcaneus – heel bone; articulates with tallus

-c. Cuboid – lateral

-d. Navicular – medial

-e. Cuneiform bones – anterior medial, intermediate, and lateral

2. Metatarsus – metatarsal bones; numbered from medial (big toe) 1 to 5

3. Phalanges – 14; 2 on big toe; 3 on other 4

DEVELOPMENT

Fontanels

1. Fontanels – remnants of unossified remnants; compressed during birth

2. Anterior fontanel – between frontal and parietal; 1.5 to 2 years after birth; superior

3. Sphenoid fontanel – sphenoid, temporal, frontal, and parietal; lateral

4. Mastoid fontanel – temporal, occipital, and parietal; lateral

5. Posterior fontanel – between parietal and occipital