1. Chapter 7: The Axial Skeleton part 1

2. The Axial Skeleton - longitudinal axis
Supports and protects organs in body cavities
Attaches to muscles of:
head, neck, and trunk
respiration
appendicular skeleton

3. Bones of the Axial Skeleton - 80
The skull:
8 cranial bones
14 facial bones
The thoracic cage:
24 ribs
the sternum
Bones associated with the skull:
6 auditory ossicles
the hyoid bone
The vertebral column:
24 vertebrae
the sacrum
the coccyx

4. The Skull The skull protects: Has 22 bones: the brain
entrances to respiratory and digestive system
Has 22 bones:
8 cranial bones:
form the braincase or cranium
14 facial bones:
protect and support entrances to digestive and respiratory tracts

5. Cranial Bones

6. 1. The Frontal Bone Forms the anterior cranium and upper eyesockets
Contains frontal sinuses
Figure 7–6

7. The Frontal Bone-con’t
Marks
Frontal squama/glabella (forehead)
Supraorbital margin (protects eye)
Lacrimal fossa (for tear ducts)

8. 2-3. The Parietal Bones
forms part of the superior and lateral surfaces of the cranium

9. 4-5. The Temporal Bones
Part of lateral walls of cranium and zygomatic arches
Surround and protect inner ear
Attach muscles of jaws and head
Figure 7–7

10. Marks Mandibular fossa-articulates with the mandible
Zygomatic process:
inferior to the squamous portion
articulates with temporal process of zygomatic bone
forms zygomatic arch (cheekbone)

11. Mastoid process: Styloid process: Auditory ossicles:
for muscle attachment
contains mastoid air cells connected to middle ear
Styloid process:
to attach tendons and ligaments of the hyoid, tongue and pharynx
Auditory ossicles:
3 tiny bones in tympanic cavity (middle ear)
transfer sound from tympanic membrane to inner ear

13. Foramina Carotid canal: Foramen lacerum: for internal carotid artery
for carotid and small arteries
hyaline cartilage
auditory tube

14. Cranial Bones - 8 6. The Occipital Bone Marks Foramina
Forms posterior/inferior surfaces of cranium
Largest cranial bone
Marks
Occipital condyles -articulate with neck
Inferior and superior nuchal lines -to attach ligaments
External occipital protuberance(Inion)-
for trapezius attachment
External occipital crest -to attach ligaments
Foramina
Foramen magnum-connects cranial and spinal cavities

15. 7. The Sphenoid Part of the floor of the cranium
Unites cranial and facial bones
Strengthens sides of the skull
Contains sphenoidal sinuses
Figure 7–8

16. Marks Sphenoid body: at the central axis of the sphenoid
Sella turcica:
saddle-shaped enclosure
on the superior surface of the body
Lesser wings:
anterior to the sella turcica
Greater wings:
form part of the cranial floor
sphenoidal spine
posterior wall of the orbit
Hypophyseal fossa:
a depression within the sella turcica
holds the pituitary gland
Sphenoidal sinuses:
either side of the body
inferior to the sella turcica

17. 7. The Ethmoid Forms anteromedial floor of the cranium
Roof of the nasal cavity
Part of the nasal septum and medial orbital wall
Contains ethmoidal (sinuses)
Figure 7–9

18. Foramina Optic canals: Superior orbital fissure: Foramen rotundum:
for optic nerves
Superior orbital fissure:
For blood vessels and nerves of the orbit
Foramen rotundum:
for blood vessels and nerves of the face
Foramen ovale:
for blood vessels and nerves of the face
Foramen spinosum:
for blood vessels and nerves of the jaws

19. Ethmoid
Cribiform plate
roof of the nasal cavity
-contains crista galli
Perpendicular plate is part of the nasal septum
Olfactory foramina in the cribriform plate for olfactory nerves

20. The 4 Major Sutures (immovable joints of the skull)
Lambdoid suture-separates occipital from parietal bones
Coronal suture-attaches frontal bone to parietal bones
Sagittal suture-between the parietal bones lambdoid suture to coronal suture
Squamous suture-form boundaries between temporal bones and parietal bones

21. The Infant Skull Grows rapidly Is large compared to the body
Has many ossification centers
Fusion is not complete at birth:
2 frontal bones
4 occipital bones
several sphenoid and temporal elements
Figure 7–15

22. Fontanels Are areas of fibrous connective tissue (soft spots)
Cover unfused sutures in the infant skull
Allow the skull to flex during birth
Anterior fontanel-frontal, sagittal, and coronal sutures
Occipital fontanel-lambdoid and sagittal sutures

23. The Facial Bones Superficial facial bones for muscle attachment
Maxillary
Lacrimal
Nasal
Zygomatic
Mandible
Deep facial bones separate the oral and nasal cavities & form the nasal septum
Palatine bones
Inferior nasal conchae
Vomer

24. Facial Bones - 14 Maxillary (2) - Functions Support upper teeth
Form inferior orbital rim
Form lateral margins of external nares
Form upper jaw and hard palate
Contain maxillary sinuses (largest sinuses)
-failure to fuse results in cleft palate
Figure 7–10a

25. Marks
Anterior nasal spine-attaches cartilaginous anterior nasal septum
Alveolar processes-borders the mouth, supports upper teeth
-Maxillary sinuses-to lighten bone
-Infraorbital foramen:
for sensory nerve to brain (via foramen rotundum of sphenoid)

26. The Palatine Bones (2) Functions
Form the posterior portion of the hard palate
Contribute to the floors of the orbits
Figure 7–10b,c

27. Nasal Bones- 2 -Support the bridge of the nose
Connect to cartilages of the distal part of the nose (external nares)

28. Vomer (1)
Forms the inferior portion of the bony nasal septum

29. Inferior Nasal Conchae (2)
-create air turbulence in the nasal cavity, increase the epithelial surface area, warm and humidify inhaled air

30. Zygomatic Bones (2)
Contribute to the rim and lateral wall of the orbit
Form part of the zygomatic arch
Marks
Temporal process

31. Lacrimal Bones (2) (smallest facial bones)
Form part of the medial wall of the orbit
Lacrimal sulcus:
location of the lacrimal sac

32. milk eye squirt - YouTube

33. The Mandible (1) Articulations Forms the lower jaw
Mandibular fossae of the temporal bones
Body of the mandible - horizontal portion
Alveolar processes - support the lower teeth
Ramus - ascending from the mandibular angle on either side
Figure 7–12a,b

34. Foramina Mental foramen-for sensory nerves of lips and chin
Mandibular foramen-for blood vessels and nerves of lower teeth

35. The Hyoid Bone (assoc w/facial bones)
Functions
Supports the larynx
Attaches muscles of the larynx, pharynx, and tongue
Articulations
Connects lesser horns to styloid processes of temporal bones