1. CHAPTER 7 “The Axial Skeleton” Review your A&P revealed discs Course objectives: Define and identify the bones of the axial skeleton

2. Axial Skelton 80 total bones
consists of the bones that form the long axis of the body including the:
Skull (total 28 with ear bones)
Vertebral column [(total 26) C7;T12; L5; S1; Co1]
Bony thorax [ribs and sternum (total 25)]
Hyoid bone (1)

3. Bones of the axial skeleton

4. Axial Skelton

5. Skull Bones Review A&P revealed discs animation of skull
the skull has two major divisions: Cranium and Facial bones
Cranium – the 8 bones that enclose the brain.
-1 occipital, 1 frontal, 2 parietal, 2 temporal, 1 sphenoid and 1 ethmoid.
These typical flat bones of the cranium are connected by a special kind of joint called a suture (Synarthroses).

6. Cranial bones

7. Cranial Bones Midsaggital section

8. Cranial Bones Midsaggital section

9. Cranium Made up of 2 major divisions:
Calvarium (skull cap)
Base
Base contains three large depressions (fossa):
Anterior cranial fossa where the frontal lobes sit
Middle cranial fossa where the temporal lobes sit
Posterior cranial fossa where the cerebellum sits

10. Cranial Bones

11. Cranial Bones

12. Sutures/Sutural Bones
Sutures (synarthroses) are immovable fibrous joints.
-all bones in the skull, except for the jaw, are united by sutures. The major sutures are:
-Coronal -Sagittal
-Squamous -Lamboid
Sutural bones- small bones that occur within the sutures, especially the lamboid suture. They are not present in all people.

13. Sutures/Sutural Bones

14. Facial bones
There are 14 bones that can be thought of as creating the face.
As part of this function they provide:
- protection for many sense organs,
-anchors for many muscles
-the openings for air and food to pass.
Facial Bones
2-maxillae; 2-palatine; 2-nasal; 2- zygomatic;
2-lacrimal; 2-inf nasal conchae; 1- vomer; and 1-mandible

18. Sphenoid bone
Looks like a Bat in flight. Greater and lesser wings; optic foramen; sella turcica, superior orbital fissure. Dorsal view.

19. Sphenoid bone
Dorsal view
Anterior view

20. Ethmoid bone Anterior to sphenoid bone forms anterior base of skull
and nasal cavity.
Cribriform plate.
Crista gali
Perpendicular
plate

21. Ethmoid bone

22. Ethmoid bone

23. Foramen/ Orbits
Foramen: Special openings in bones where nerves, blood vessels enter into the bone cavity.
- Ex.: Foramen magnum, Supraorbital Infraorbital, Mental, Jugular, Olfactory, Mandibular
Orbits: Cone shaped bony cavities that hold the eyes, fat, occular muscles and tear glands.

24. Bones of the eye orbit

25. Meatus/ Sinuses Meatus: a canal or opening into bone
- Ex.: external auditory, internal acoustic
Sinus: cavities within bones filled with air.
-Ex.: frontal, ethmoid, sphenoid and maxillary sinuses

26. Cranial sinuses

27. Cranial fossa
Fossa are depressions or cavities in the skull.

28. The Fetal Skull Sutures are called fontanels in fetus. Fontanels
-Frontal (anterior)
-Occipital (posterior)
-Sphenoidal (anterior lateral)
-Mastoid (posterior lateral)

29. The Fetal Skull

30. The Fetal Skull