Download Axial Skeleton

Axial Skeleton
A. Definition—longitudinal axis of body.
vertebral column, & bony thorax
Skull,
B. Bones of the skull: 2 parts; the cranium and the
facial bones
1. Cranium—encloses & protects fragile brain tissue
a. Frontal
b. Parietal
c. Temporal
d. Occipital
e. Sphenoid
f. Ethmoid
2. Facial bones—holds eyes in the anterior portion
of head and allows for muscle attachment/expressions
a. Mandible
b. Maxilla
c. Palatine
d. Zygomatic
e. Lacrimal
f. Nasal
g. Vomer
C. Hyoid—only bone in human body that doesn’t
articulate with another bone.
D.
Fetal Skull
1. Large compared to body size (about ¼ of body, in
adults 1/8)
2. fontenels—soft spots, allow for depression
during birth and brain growth.
3. ossification between 22 – 24 months
E. Vertebral Column—supports skull and extends to
pelvis
1. flexible, curved structure of 26 irregular bones
(33 at infancy)
2. spinal cord runs through the center
HA&P—Axial Skeleton
3. Intervertebral discs—flexible fibrocartilage to
cushion and protect.
4. Five types of vertebrae:
a. Cervical (7)
b. Thoracic (12)
c. Lumbar (5)
d. Sacrum (5 fused)
e. Coccyx (3 – 5 fused)
5. Vertebrae anatomy
a. Body—weight bearing part facing anteriorly
to vertebral column
b. vertebral foramen—canal for spinal cord
c. transverse process—2 lateral projections
d. spinous process—single projection from
posterior aspects of vertebral arch
e. superior/inferior articular processes—form
joints with adjacent vertebrae
6.
Disorders of the Vertebrae
a. Scoliosis—spine curves left or right
b. Kyphosis—“hump” at cervical vertebrae
c. Lordosis—extreme curving at lumbar vertebrae
d. Herneated “slipped” disc—drying discs which
press on spinal nerves or spinal cord
F.
Bony Thorax
1. Sternum
a. Manubrium
b. Body
c. xiphoid process
2.
Ribs
a. 12 pairs, male and female
b. true ribs (7) attach directly to sternum
c. false ribs (5) attach indirectly to sternum
(or not at all)
d. floating ribs (last 2)—lack sternal
attachments
e. intercostal spaces—spaces between ribs, aid
in breathing
HA&P—Axial Skeleton
HA&P—Axial Skeleton