Skeletal System

Bones and Bone Parts Studied in the Laboratory
(Your instructor will indicate your exact assignment)


I. Axial Skeleton

            A. Skull - Cranial fossae of the cranial cavity.

1. Anterior cranial fossa - contains frontal cerebral lobes, olfactory bulbs and olfactory tracts.

2. Middle cranial fossa - contains pituitary gland, optic nerves and optic chiasma, temporal cerebral lobes, cranial nerves 3 and 4.

3. Posterior cerebral fossa - contains medulla oblongata, pons, cerebellum, and the 5th to 12th cranial nerves.

B. Skull - Cranial Bones - 8 bones house brain, cranial nerves and cranial blood vessels; dipl e construction.

1. Frontal

a. frontal crest

b. frontal sinuses

c. orbital plate

2. Parietal

3. Occipital

a. foramen magnum

b. occipital condyles

4. Temporal

a. acoustic meatus

b. mastoid process

c. styloid process

d. zygomatic process

e. petrous ridge - inner ear is in here; fracture through floor of skull can fracture this ridge - release cerebrospinal fluid into ear canal or nasal cavity - test liquid with sugar dip stick.

5. Ethmoid

a. crista galli

b. cribriform plate - very thin (car accident - nose hits rear-view mirror and damages this plate - anosmia (loss of sense of smell).

c. perpendicular plate

d. orbital plate

e. superior nasal concha

f. middle nasal concha

                6. Sphenoid - note that this bone articulates with every other skull bone except the mandible. It is sometimes called the "keystone."

a. orbital surface

b. greater wing

c. lesser wing

d. sella turcica

e. optic foramen

f. clinoid processes

C. Skull - Facial Bones - 14 bones that make up the front of the head

1. Nasal

2. Lacrimal

3. Zygomatic - facial zone that is particularly strong - can take a blow.

a. orbital surface

4. Maxilla - sinuses of maxilla and teeth - infections can go back and forth.

a. orbital surface

b. infraorbital foramen

c. palatine process

5. Mandible - contains 16 teeth in adult; 10 in children

a. body

b. ramus

c. angle

d. mental foramen

e. condylar process - can be felt by finger in one's ear.

6. Palatine

7. Vomer

8. Inferior nasal concha

D. Vertebral Column

1. 7 cervical vertebrae - 1st is Atlas, 2nd is Axis, rest are C3 - C7. Support the skull.

No discs between skull and C1, and C1 and C2. C1 has a wide vertebral foramen to accommodate the medulla as it becomes the spinal cord.

2. 12 thoracic vertebrae - T1 - T12. These have articulating ribs. Support the thorax

3. 5 lumbar vertebrae - L1 - L5. These are large - bear weight of body.

4. Sacrum - connects to the ilia - lots of stress in the sacro-iliac joint. Acts as a keystone to transmit force downward to legs. S1 can be free - lumbarized 1st sacral.

a. sacral foramina

b. medial crest

c. superior articular process

5. Coccyx - 3-5 vertebrae normally. No discs

6. On any vertebra and adjacent vertebrae

a. body

b. spinous process

c. transverse process

d. vertebral foramen

e. superior articulating facets

f. inferior articulating facets

7. On adjacent vertebrae

a. intervertebral disc - round concentric ligaments with a core of connective pulp.

b. intervertebral foramen

8. Landmarks

a. open mouth - C2 directly in back.

b. feel for hyoid bone in angle of neck and swallow - hyoid is at level of C3.

c. Adam's apple - level of C6.

d. sternal notch - level of T2.

e. bottom of sternum - level of T9.

f. belly button (naval) - level of L4.

g. one hand-breadth above naval - L2 - where spinal cord ends.

h. rest your hands on iliac crests - level of L4.

i. rest hands on anterior superior spines of ilia - level of S2.

j. pubic bones on front of pelvis - level of S4 - S5.

E. Thoracic Cage

1. Sternum

a. manubrium

b. body

c. xiphoid process

d. suprasternal notch

2. Ribs

a. head

b. articular facets on ribs 2- 10.

c. floating ribs

d. costal cartilages

II. Appendicular Skeleton

A. Pectoral Girdle

1. Scapula

a. vertebral border

b. superior angle

c. scapular notch

d. coracoid process

e. axillary border

f. inferior angle

g. acromion process

h. spine

i. glenoid cavity

2. Clavicle

1. acromial end

2. sternal end

B. Upper Limb

1. Humerus

a. head

b. anatomical neck

c. surgical neck

d. greater tubercle

e. lesser tubercle

f. intertubercular groove

g. deltoid tuberosity

h. radial fossa

i. coronoid fossa

j. olecranon fossa

k. capitulum

l. trochlea

2. Radius

a. head

b. neck

c. radial tuberosity

d. ulnar notch

e. styloid process

f. articular facets

3. Ulna

a. trochlear (semilunar) notch

b. olecranon process

c. coronoid process

d. head

4. Carpus (wrist) - 8 carpal bones

a. distal row

(1) trapezium

(2) trapezoid

(3) capitate

(4) hamate

(a) hook

b. proximal row

(1) scaphoid

(2) lunate

(3) triquetral

(4) pisiform

5. Palm - 5 metacarpal bones

a. For each: base, body and head

6. Phalanges (singular - phalanx); proximal, middle, distal for each finger (note thumb or pollox only has proximal and distal).

C. Pelvic Girdle

1. 2 os coxae (singular - os coxa) composed of 3 fused bones:

a. ilium

(1) iliac crest

(2) greater sciatic notch

(3) fossa

(4) anterior superior spine

b. ischium

(1) ischial tuberosity

(2) lesser sciatic notch

c. pubis

(1) note the pubic symphysis between the 2 pubic bones

2. Sacrum

a. note the sacro-iliac joint between the ilium of each os coxa and the sacrum

3. Pelvic inlet

4. Pubic arch - note the angle: 90 and greater seen more often in female skeletons.

5. Obturator foramen

6. Acetabulum

D. Lower Limb

1. Femur

a. head

b. neck

c. greater trochanter

d. lesser trochanter

e. intertrochanteric crest

f. linea aspera

g. shaft

h. condyles

(1) medial

(2) lateral

i. epicondyles

(1) medial

(2) lateral

j. intercondylar fossa

k. patellar surface

2. Patella

3. Tibia

a. condyles

(1) medial

(2) lateral

b. tibial tuberosity

c. anterior crest

d. medial malleolus

4. Fibula

a. head

b. lateral malleolus

5. Tarsus - ankle; 7 tarsal bones

a. calcaneus

(1) tuberosity

b. cuboid

c. talus

(1) trochlear surface

d. navicular

e. cuneiform bones

(1) medial (articulates with the hallux or big toe)

(2) intermediate

(3) lateral

6. Metatarsals (one's instep)

a. for each - head, shaft, base

7. Phalanges - (singular - phalanx); proximal, middle, distal for each toe (note hallux only has proximal and distal).

Return to Skeletal System - Essential Facts and Problems