1. Fundamentals of Anatomy & Physiology
Eleventh Edition
Chapter 7
The Axial Skeleton
Lecture Presentation by
Deborah A. Hutchinson
Seattle University
© 2018 Pearson Education, Inc.

2. Learning Outcomes
7-1 Identify the bones of the axial skeleton, and specify their functions. 7-2 Identify the bones, foramina, and fissures of the cranium and face, and explain the significance of the markings on the individual bones. 7-3 Describe the structure and functions of the orbital complex, nasal complex, and paranasal sinuses. 7-4 Describe the key structural differences among the skulls of infants, children, and adults.
© 2018 Pearson Education, Inc.

3. Learning Outcomes
7-5 Identify and describe the curves of the spinal column, and indicate the function of each. 7-6 Identify the five vertebral regions, and describe the distinctive structural and functional characteristics of the vertebrae in each region. 7-7 Explain the significance of the joints between the thoracic vertebrae and ribs, and between the ribs and sternum.
© 2018 Pearson Education, Inc.

4. Divisions of the Skeleton
Axial skeleton
Bones of head and trunk
Forms longitudinal axis of body
Appendicular skeleton
Bones that support the limbs
© 2018 Pearson Education, Inc.

5. Figure 7–1a The Axial Skeleton.
SKELETAL SYSTEM
206
AXIAL SKELETON 80
APPENDICULAR SKELETON
(see Figure 8-1)
Cranium 8
Skull
Face 14
Skull and
associated
bones 29
Auditory
ossicles 6
Associated
bones
Hyoid 1
Sternum 1
Thoracic
cage 25
Ribs 24
Vertebrae 24
Vertebral
column 26
Sacrum 1
Coccyx 1
ATLAS: Plates 1a,b a
An anterior view of the entire
skeleton, with the axial components
highlighted. The numbers in the
boxes indicate the number of bones
in the adult skeleton.
© 2018 Pearson Education, Inc.

6. Figure 7–1b The Axial Skeleton.
Skull
Skull
Cervical
vertebrae
Sternum
Thoracic
vertebrae
Ribs
Ribs
Costal
cartilages
Lumbar
vertebrae
Lumbar
vertebrae
ATLAS: Plates 1a,b
Sacrum
Sacrum
Coccyx
Coccyx b
Anterior (top) and posterior (bottom) views of the axial skeleton.
The individual bones associated with the skull are not visible.
© 2018 Pearson Education, Inc.

7. The Axial Skeleton Axial skeleton has 80 bones Skull
8 cranial bones and 14 facial bones
Bones associated with the skull
6 auditory ossicles and hyoid bone
Thoracic cage
Sternum and 24 ribs
Vertebral column
24 vertebrae, sacrum, and coccyx
© 2018 Pearson Education, Inc.

8. The Axial Skeleton Functions of the axial skeleton
Supports and protects organs in body cavities
Provides points of attachment for muscles that
Adjust positions of head, neck, and trunk
Perform breathing movements
Stabilize parts of appendicular skeleton
© 2018 Pearson Education, Inc.

9. Figure 7–17 The Vertebral Column.
Spinal Curves
Vertebral Regions
Primary curves develop
before birth, and secondary
curves after birth.
Regions are defined
by structural
characteristics of
individual vertebrae. C1
The cervical curve, a secondary
curve, develops as the infant
learns to balance the weight of its
head on the vertebrae of the neck. C2 C3 C4
Cervical
(7 vertebrae) C5 C6 C7 T1 T2 T3 T4 T5
The thoracic curve, a
primary curve, provides
room for the thoracic
organs. T6 T7
Thoracic
(12 vertebrae) T8 T9
T10
T11
T12
ATLAS: Plate 2b L1
The lumbar curve, a second-
ary curve, balances the weight
of the trunk over the lower limbs.
This curve develops with the
ability to stand. L2
Lumbar
(5 vertebrae) L3 L4 L5
The sacral curve, a
primary curve, provides
room for various
abdominopelvic organs.
Sacral
Coccygeal
© 2018 Pearson Education, Inc.

10. The Vertebral Column Vertebrae Neck Seven cervical vertebrae
Upper back
12 thoracic vertebrae
Each articulates with one or more pairs of ribs
Lower back
Five lumbar vertebrae
© 2018 Pearson Education, Inc.

11. The Vertebral Column Vertebral anatomy
Each vertebra consists of three parts
Vertebral body
Vertebral arch
Articular processes
© 2018 Pearson Education, Inc.

12. The Five Vertebral Regions
Vertebral anatomy
Vertebral body
Transfers weight along the spine
Forms anterior margin of each vertebral foramen
Vertebral arch forms posterior margin of each vertebral foramen
Walls are called pedicles
Laminae form roof
Articular processes
Lateral projections between laminae and pedicles
© 2018 Pearson Education, Inc.

13. Figure 7–18a Vertebral Anatomy.
Vertebral arch
Articular processes
Pedicle
Laminae
Vertebral body a
The major parts of a typical vertebra
© 2018 Pearson Education, Inc.

14. The Five Vertebral Regions
Vertebral anatomy
Spinous process
Posterior projection from where vertebral laminae fuse
Transverse processes
Projections from where laminae join pedicles
Superior and inferior articular processes
Have articular facets
For articulations with neighboring vertebrae
© 2018 Pearson Education, Inc.

15. Figure 7–18b Vertebral Anatomy.
Superior articular
process
Pedicle
Transverse
process
Vertebral body
Spinous
process
Inferior articular
facet
Arrow passing
through vertebral
foramen
Inferior articular
process b
A lateral and slightly inferior view of a vertebra
© 2018 Pearson Education, Inc.

16. Figure 7–18c Vertebral Anatomy.
Spinous process
Superior
articular
process
Inferior
articular
process
Transverse
process
Inferior
articular
facet
Pedicle
Vertebral
foramen
Vertebral
body c
An inferior view of a vertebra
© 2018 Pearson Education, Inc.

17. The Five Vertebral Regions
Vertebrae are numbered
By region, from top (superior) to bottom (inferior)
C1 articulates with skull, L5 with sacrum
Vertebrae of each region
Have characteristics determined by functions
© 2018 Pearson Education, Inc.

18. The Five Vertebral Regions
Regions of the vertebral column
Cervical (C)
Thoracic (T)
Lumbar (L)
Sacral (S)
Coccygeal (Co)
© 2018 Pearson Education, Inc.

19. The Five Vertebral Regions
Cervical vertebrae
C1 to C7
Small body (support only head)
Large vertebral foramen (largest part of spinal cord)
Concave superior surface
Anterior edge is inferior to posterior edge
© 2018 Pearson Education, Inc.

20. The Five Vertebral Regions
Cervical vertebrae
Transverse processes are fused to costal processes
Encircle transverse foramina for vertebral arteries and vertebral veins
All except C1 have spinous processes
Tips of most spinous processes are notched (bifid)
Whiplash—partial or complete dislocation of cervical vertebrae
© 2018 Pearson Education, Inc.

21. Figure 7–19a The Cervical Vertebrae.
Spinous
process of
vertebra
prominens
ATLAS: Plates 20b; 21a–e C7 a
A lateral view of the cervical
vertebrae, C1–C7.
© 2018 Pearson Education, Inc.

22. Figure 7–19b The Cervical Vertebrae.
Vertebral
arch
Spinous process
Lamina
Vertebral
foramen
Superior articular
process
Pedicle
Vertebral body
Transverse
process
Superior
articular
facet
Transverse
foramen
Costal process b
A superior view of a representative cervical
vertebra (C3–C6). Note the typical features
listed in Table 7–1.
© 2018 Pearson Education, Inc.

23. The Five Vertebral Regions: The Atlas
Cervical vertebrae
The atlas (C1)
Articulates with occipital condyles of skull
Has no body or spinous process
Has a large, round vertebral foramen within anterior and posterior arches
© 2018 Pearson Education, Inc.

24. The Five Vertebral Regions: The Atlas
© 2018 Pearson Education, Inc.

25. The Five Vertebral Regions: The Axis
Cervical vertebrae
The axis (C2)
Articulates with the atlas
Has heavy spinous process to attach muscles of head and neck
Bodies of axis and atlas fuse during development to form the dens
© 2018 Pearson Education, Inc.

26. The Five Vertebral Regions: The Axis
© 2018 Pearson Education, Inc.

27. © 2018 Pearson Education, Inc.

28. Figure 7–19d The Cervical Vertebrae.
Dens of
axis
Anterior
arch
Transverse
ligament
Atlas
(C1)
Posterior
arch
Axis (C2) d
The atlas (C1) and axis (C2) in posterolateral view.
© 2018 Pearson Education, Inc.

29. The Five Vertebral Regions
Thoracic vertebrae (T1–T12)
Have heart-shaped bodies
Larger bodies and relatively smaller vertebral foramina than those in cervical vertebrae
Long, slender spinous process
Dorsolateral surfaces of body have costal facets
Articulate with heads of ribs
© 2018 Pearson Education, Inc.

30. The Five Vertebral Regions
Thoracic vertebrae
T1–T8 each articulate with two pairs of ribs
At superior and inferior costal facets
T9–T11 articulate with one pair of ribs
T1–T10
Have thick transverse processes
With transverse costal facets for rib articulation
Ribs pairs 1–10
Contact costal and transverse costal facets
T10–T12 transition to lumbar vertebrae
© 2018 Pearson Education, Inc.

31. Figure 7–20a The Thoracic Vertebrae.
prominens C7 T1 T2
Intervertebral
foramen T3 T4 T5 T6 T7
Thoracic
vertebrae
(T1–T12) T8 T9
T10
ATLAS: Plates 22a–c
T11
T12 L1 a
A lateral view of the thoracic region of the vertebral column.
The vertebra prominens (C7) resembles T1, but lacks facets
for rib articulation. Vertebra T12 resembles the first lumbar
vertebra (L1) but has a facet for rib articulation.
© 2018 Pearson Education, Inc.

32. Figure 7–20b The Thoracic Vertebrae.
Spinous
process
Transverse
process
Lamina
Transverse
costal facet
Superior
articular
facet
Vertebral
foramen
Superior
costal facet
ATLAS: Plates 22a–c
Vertebral
body b
Thoracic vertebra, superior view.
© 2018 Pearson Education, Inc.

33. Figure 7–20c The Thoracic Vertebrae.
Superior costal
facet for head of
superior rib
Transverse costal
facet for tubercle
of superior rib
Transverse
process
Vertebral
body
Spinous
process
Inferior costal
facet for head of
inferior rib
ATLAS: Plates 22a–c c
Thoracic vertebra, lateral view.
© 2018 Pearson Education, Inc.

34. The Five Vertebral Regions
Lumbar vertebrae (L1–L5)
Largest vertebrae
Thick, oval-shaped bodies
No costal facets or transverse costal facets
Triangular vertebral foramen
Superior articular processes face medially
Inferior articular processes face laterally
Slender transverse processes project dorsolaterally
Massive spinous processes
For attachment of lower back muscles
© 2018 Pearson Education, Inc.

35. Figure 7–21a The Lumbar Vertebrae.
ATLAS: Plates 23a–c
Sacrum
Coccyx a
A lateral view of the lumbar
vertebrae, sacrum, and coccyx
© 2018 Pearson Education, Inc.

36. Figure 7–21b The Lumbar Vertebrae.
Spinous process
Superior articular facet
Lamina
Superior articular
process
Transverse
process
Transverse process
Vertebral
foramen
Pedicle
ATLAS: Plates 23a–c
Vertebral
body b
Superior view of typical lumbar vertebra
© 2018 Pearson Education, Inc.

37. Figure 7–21c The Lumbar Vertebrae.
Superior articular
process
Pedicle
Transverse process
Vertebral
body
Spinous
process
Inferior articular
process
ATLAS: Plates 23a–c
Inferior articular facet c
Lateral view of a typical lumbar vertebra
© 2018 Pearson Education, Inc.

38. Table 7–1 Regional Differences in Vertebral Structure and Function (Part 2 of 2)
© 2018 Pearson Education, Inc.

39. The Five Vertebral Regions
Sacrum and coccyx
L5 articulates with the sacrum
Sacrum articulates with the coccyx
© 2018 Pearson Education, Inc.

40. The Five Vertebral Regions
Sacrum
Curved, more so in males than in females
Protects reproductive, urinary, and digestive organs
Attaches
Axial skeleton to pelvic girdle
Broad muscles that move the thigh
© 2018 Pearson Education, Inc.

41. The Five Vertebral Regions
Sacrum
The adult sacrum
Consists of five fused sacral vertebrae
Fusion occurs between puberty and ages 25–30
Leaving transverse lines
Sacral canal
Passageway that extends the length of the sacrum
Contains nerves and membranes
© 2018 Pearson Education, Inc.

42. 7-6 The Five Vertebral Regions
Sacrum
Median sacral crest
Ridge formed from fused spinous processes
Four pairs of sacral foramina open to either side
Lateral sacral crest
Ridge formed from fused transverse processes
Attaches to muscles of lower back and hip
© 2018 Pearson Education, Inc.

43. 7-6 The Five Vertebral Regions
Sacrum
Sacral cornua
Ridges formed from laminae of fifth sacral vertebra
Laminae do not meet at midline
Sacral hiatus
Opening at inferior end of sacral canal
Bordered by sacral cornua
Covered by connective tissues
© 2018 Pearson Education, Inc.

44. Figure 7–22a The Sacrum and Coccyx.
Articular
process
Entrance to
sacral canal
Sacral
tuberosity
Lateral
sacral crest
Sacral
foramina
Median
sacral crest
Sacral cornu
Sacral hiatus
Coccygeal cornu
Coccyx a
A posterior view
© 2018 Pearson Education, Inc.

45. 7-6 The Five Vertebral Regions
Sacrum
Apex
Narrow inferior portion
Articulates with the coccyx
Base
Broad superior surface
Sacral promontory
Prominent bulge at anterior tip of base
Ala
A wing on either side of the base
To attach muscles
© 2018 Pearson Education, Inc.

46. Figure 7–22c The Sacrum and Coccyx.
Base
Sacral
promontory
Ala
Ala
Sacral
foramina
Transverse
lines
Apex
Coccyx c
An anterior view
© 2018 Pearson Education, Inc.

47. The Five Vertebral Regions
Coccyx
Mature coccyx
Consists of three to five fused coccygeal vertebrae
Attaches ligaments and a constricting muscle of the anus
First two coccygeal vertebrae have transverse processes
And unfused vertebral arches
Coccygeal cornu
Prominent lamina of first coccygeal vertebra
© 2018 Pearson Education, Inc.

48. Figure 7–22b The Sacrum and Coccyx.
Sacral
promontory
Auricular
surface
Lateral
sacral crest
Median
sacral crest
Sacral curve
Sacral cornu
Coccygeal cornu
Coccyx b
A lateral view from the right side
© 2018 Pearson Education, Inc.