1. The Axial Skeleton

2. I highly recommend Professor Wissman’s sites
For bones:
Check out all his links:
Also check out:
Site for xrays & other diagnostic procedures:

3. Prof Wissman’s bone site; this doesn’t show the roll-over answers
This is an example of
Prof Wissman’s bone site; this doesn’t show the roll-over answers

4. THE SKELETAL SYSTEM The Axial Skeleton
The skeleton consists of
Bones (206)
Cartilages
Joints – also called articulations, are the junctions between skeletal elements
Ligaments – connect bones
Divided into axial and appendicular

5. Axial skeleton - forms long axis of body
Skull
Vertebral column
Thoracic cage
Appendicular skeleton – appendages and what they attach to
Upper limbs (arms)
Pectoral girdle (shoulder)
Lower limbs (legs)
Pelvic girdle

6. Axial skeleton Vertebral column Thoracic cage
Skull
Vertebral column
Thoracic cage
Axial skeleton is shown in green

7. The Skull Cranial bones (or cranium)
Enclose the cranial cavity, which supports and protects the brain
Attachment sites for some head and neck muscles
Facial bones (anterior aspect of skull)
Form framework of face
Form cavities for sense organs of sight, taste and smell
Provides openings for passage of air and food
Hold the teeth
Anchor the muscles of the face

8. Cranial bones Frontal bone Parietal bones (paired) Occipital bone
Temporal bones (paired)
Sphenoid bone
Ethmoid bone

9. Cranial bones frontal parietal parietal parietal _______sphenoid
temporal
_____ethmoid
occipital
occipital

10. Cranial “cavity” – houses brain Smaller cavities
Housing middle and inner ear
Nasal cavity
Orbits
Sinuses
Openings (foramina, canals, fissures) for:
Spinal cord
Blood vessels
Twelve cranial nerves: I-XII

11. Remember, the skull is composed of:
Cranial bones (or cranium)
[these were just reviewed]
and
Facial bones (anterior aspect of skull)
Form framework of face
Form cavities for sense organs of sight, taste and smell
Provides openings for passage of air and food
Hold the teeth
Anchor the muscles of the face

12. Facial bones Mandible Vomer Maxillae (paired) Zygomatics (paired)
Nasal (paired)
Lacrimal (paired)
Palatines (paired)
Inferior nasal conchae (paired)

13. Facial bones:
Mandible
Vomer
Maxillae (paired)
Zygomatics (paired)
Nasal (paired)
Lacrimal (paired)
Palatines (paired)
Inferior nasal conchae (paired)

14. Cranium Vault – “calvaria” = skullcap Base or floor: inferior part
Forms superior, lateral and posterior aspects of skull, and forehead
Base or floor: inferior part
Prominent bony ridges divide cranial base into 3 “fossae” (steps) – anterior, middle and posterior
Anterior cranial fossa
Middle cranial fossa
Posterior cranial
fossa
(looking down on the floor of the skull)

19. Maxilla (there are 2 which fuse, forming the upper jaw)
Mandible (lower jaw)

20. Hyoid bone Only bone which does not articulate with any other bone
Moveable base for the tongue
Points of attachment for neck muscles that raise and lower the larynx during swallowing

21. Remember that the Axial skeleton includes:
Skull
Vertebral column
Thoracic cage
Axial skeleton is shown in green

22. The Vertebral Column Fetus and infant: 33 separate bones, or vertebrae
Adult: 24 vertebrae
Inferior 9 have fused forming
The sacrum (5) and
The coccyx (4)

23. Vertebrae Cervical – 7 Thoracic - 12 Lumbar - 5 Sacrum (5 fused)
Coccyx (4 fused)

24. Spinal curvatures
Cervical and lumbar are concave posteriorly* (lordosis)
Thoracic and sacral are convex posteriorly* (kyphosis)
Abnormal (see lab book p120):
Too much of either
Scoliosis (more than 10 degrees of lateral curvature)
*when viewed from the side

26. The Sacrum Coccyx Shapes posterior wall of pelvis
Composite bone of 5 fused vertebrae
Sacral foramina allow passage of vessels & nerves
Coccyx
(the tailbone)

27. Remember that the Axial skeleton includes:
Skull
Vertebral column
Thoracic cage
Axial skeleton is shown in green

28. The Thoracic Cage

29. Sternum Ribs Manubrium Body Xiphoid process True ribs 1-7
False ribs 8-12
Floating ribs 11,12

30. Typical rib