1. The Skeletal System: Axial Division
Chapter 6 Lecture
Chapter 6
The Skeletal System: Axial Division
Frederic Martini
Michael Timmons
Robert Tallitsch

2. Introduction The axial skeleton: skull Vertebral column Rib cage
Sternum
ribs

3. Introduction
Figure 6.1a The Axial Skeleton

4. The Skull and Associated Bone
Figure 6.2 Cranial and Facial Subdivisions of the Skull

5. Sutures
Figure 6.3a The Adult Skull

6. Sutures
Figure 6.3b The Adult Skull

7. Sutures
Figure 6.3c The Adult Skull

8. The Skulls of Infants - Fontanels
Figure The Skulls of Infants

9. The cranial cavity is a chamber that supports and protects the brain.
The Cranium
The cranial cavity is a chamber that supports and protects the brain.
Bones of the cranium are the:
Occipital
Parietal (2)
Frontal
Temporal (2)
Sphenoid
Ethmoid

10. Occipital Bone
Figure 6.6a,b The Occipital Bone

11. Occipital Bone
Figure 6.3e Inferior View of Skull

12. Frontal Bone
Figure 6.7 The Frontal Bone

13. Parietal Bone
Figure 6.6c The Parietal Bone

14. Temporal Bone
Figure 6.8 The Temporal Bone

15. Temporal Bone
Figure 6.3e Inferior View of the Skull

16. Sphenoid Bone
Figure 6.9 The Sphenoid Bone

17. Sphenoid

18. Ethmoid Bone
Figure The Ethmoid

19. Ethmoid

20. Ethmoid in Skull

21. The Cranial Fossae
Figure 6.11a The Cranial Fossae

22. The Cranial Fossae
Figure 6.11b The Cranial Fossae

23. The skull contains 14 total facial bones:
The Facial Bones
The skull contains 14 total facial bones:
Paired bones:
Maxillae
Palatine
Nasal
Zygomatic
Lacrimal
Inferior nasal conchae
Single bones:
Vomer
Mandible

24. Maxillary Bones
Figure 6.12a,b The Maxillae

25. The Palatine Bones
Figure The Palatine Bones

26. The orbital complex
Figure The Orbital Complex

27. The Orbital and Nasal Complexes
FZLEMPS
Figure The Orbital Complex

28. The Inferior Nasal Conchae
Figure 6.16a,b The Nasal Complex

29. The Inferior Nasal Conchae
Figure 6.16c,d The Nasal Complex

30. The Vomer
Figure 6.5 Sectional View of the Skull

31. The Mandible
Figure The Mandible

32. The Orbital and Nasal Complexes
Figure 6.16a The Nasal Complex

33. Paranasal Sinuses
Are the interconnected hollow spaces inside the frontal, ethmoid, sphenoid, and maxillary bones.
These spaces reduce the weight of the skull, produce mucus, and allow air to resonate for voice production.
Frontal sinus, maxillary sinus, sphenoidal sinus, and the ethmoidal air cells

34. Paranasal Sinues

35. The Hyoid Bone
Figure The Hyoid Bone

36. Review of the Skull 22 Bones of the Skull: 8 form the cranium:
Occipital
Parietal (2)
Frontal
Temporal (2)
Sphenoid
Ethmoid
14 total facial bones:
Paired bones:
Maxillae
Palatine
Nasal
Zygomatic
Lacrimal
Inferior nasal conchae
Single bones:
Vomer
Mandible
PLAY
The Skull

37. The adult vertebral column has ~33 bones:
The Vertebral Column
The adult vertebral column has ~33 bones:
Vertebra (24), sacrum ( 5 fused into 1), and coccyx (3 – 5 fused into1)
Performs several functions:
Encloses and protects the spinal cord
Supports the skull
Supports the weight of the head, neck, and trunk
Transfers weight to the lower limbs
Helps maintain the upright position of the body

38. Divided into regions from superior to inferior:
The Vertebral Column
Divided into regions from superior to inferior:
Cervical (7)
Thoracic (12)
Lumbar (5)
Sacral (1); 5 fused vertebrae
Coccygeal (1); 3–5 fused vertebrae

39. Spinal curves are weight transferring anterior and posterior curves.
The spinal curves are named for the region of the vertebral column they occur in:
Cervical curve
Thoracic curve
Lumbar curve
Sacral curve
PLAY
Vertebral Column

40. Vertebral Anatomy
Figure 6.20a,b,c Vertebral Anatomy

41. Vertebral Anatomy
Figure 6.20d,e Vertebral Anatomy

42. Intervertebral disk

43. Cervical Vertebrae
There are seven total; they are the smallest, most superior vertebrae.
The spinous processes: relatively stumpy; may be split, resulting in a bifid process.
Have Transverse foramina
Superior articular facet faces up
Inferior articular facet faces down
No rib facets
C1 and C2 special – Atlas and Axis

44. The atlas has two arches, the anterior and posterior vertebral arches.
The Atlas (C1)
The atlas has no body and articulates cranially with the occipital condyles.
The articulations with the occipital condyles allow one to shake their head “yes”. 
The atlas has two arches, the anterior and posterior vertebral arches.
Superior and inferior articular facets do not extend beyond the arches.

45. The Atlas (C1)
Figure 6.22a,b The Atlas and Axis

46. The Axis (C2)
The body of the atlas fuses with the body of the axis during development to form the dens (odontoid process).
There is no intervertebral disc because of the dens.
The articulation between the atlas and axis allow one to shake their head “no”.

47. The Axis (C2)
Figure 6.22c–f The Atlas and Axis

48. Cervical Vertebrae
Bifid spinous
Transverse foramen
Superior articular facet faces superiorly

49. There are 12 total; make up the posterior of the rib cage.
Thoracic Vertebrae
There are 12 total; make up the posterior of the rib cage.
The bodies of the thoracic vertebrae have a heart shape.
The spinous process is long and slender and points on a posterocaudal angle.
The transverse processes point dorsolateral.
Articulates with ribs and therefore contain extra facets.
PLAY
Typical Thoracic Vertebrae

50. Thoracic Vertebrae
Facets for ribs

51. Lumbar Vertebrae
There are 5 total; the largest vertebrae, and make up the lower back region.
The body of lumbar vertebrae is very thick and oval shaped.
The relatively small vertebral foramen is triangular.

52. Lumbar Vertebrae
The transverse processes point more laterally than the thoracic vertebrae.
The spinous process resembles a tail fin of a fish; stumpy and flattened.
PLAY
Typical Lumbar Vertebrae

54. Sacrum and Coccyx
Figure The Sacrum and Coccyx

55. Sacrum and coccyx

57. The Thoracic Cage Has two functions:
Protects the heart, lungs, thymus, and other structures within the cavity.
Serves as the attachment site for muscles involved in:
Respiration
Positioning the vertebral column
Movements of the pectoral girdle and upper limb
PLAY
Axial Skeleton