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.
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4. Divisions of the Skeleton
Axial skeleton
Bones of head and trunk
Forms longitudinal axis of body
Appendicular skeleton
Bones that support the limbs
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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.
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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 Thoracic Cage Thoracic cage The skeleton of the chest Consists of
Thoracic vertebrae
Ribs
Costal cartilages
Sternum
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8. Figure 7–23a The Thoracic Cage.
Jugular notch T1
Clavicular articulation 1
Sternum
Manubrium 2 3
Body
True ribs
(ribs 1–7) 4
Xiphoid
process 5
ATLAS: Plate 22b
Costal
cartilages 6 10
T11 7
T12 11
Vertebrochondral
ribs
(ribs 8–10) 12 8 9
False ribs
(ribs 8–12)
Floating ribs
(ribs 11–12) a
An anterior view, showing the
costal cartilages and the sternum
© 2018 Pearson Education, Inc.

9. Figure 7–23b The Thoracic Cage.1 T2 1 2 2 T3 3 3 T4 4 4 T5 5 T6 5 6
True ribs
(ribs 1–7) T7 6 7 T8 7 8 T9 8
T10 9 9
T11 10
T12 10 11 L1 11
False ribs
(ribs 8–12) 12 12 b
A posterior view, showing the articulations
of the ribs and vertebrae
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10. The Thoracic Cage Functions of thoracic cage
Protects organs of the thoracic cavity
Including heart, lungs, and thymus
Provides attachment for muscles involved in
Breathing
Maintaining position of vertebral column
Moving pectoral girdles
Ribs and sternum form rib cage
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11. The Thoracic Cage Ribs 12 pairs of long, curved, flat bones
Extending from thoracic vertebrae
Ribs are divided into two types
True ribs
False ribs
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12. The Thoracic Cage Ribs 1–7 are true ribs Vertebrosternal ribs
Connected to sternum by costal cartilages
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13. The Thoracic Cage Ribs 8–12 are false ribs
Do not attach directly to sternum
Vertebrochondral ribs (ribs 8–10)
Costal cartilages fuse together
Merge with cartilages of rib pair 7 before reaching sternum
Floating or vertebral ribs (ribs 11–12)
Have no connection with the sternum
Connect only to vertebrae and muscles of body wall
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14. The Thoracic Cage Structures of the ribs Head (capitulum)
At vertebral end of rib
Has superior and inferior articular facets
Neck
Short area between head and tubercle
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15. The Thoracic Cage Structures of the ribs Tubercle
A small dorsal elevation
Has an articular facet that contacts transverse process of thoracic vertebra (at T1–T10 only)
Tubular body (shaft)
Attaches muscles of pectoral girdle and trunk
Attaches intercostal muscles that move the ribs
© 2018 Pearson Education, Inc.

16. A superior view of a rib showing the joints between it
Figure 7–24a The Ribs.
Transverse
costal facet
Tubercle of rib
Angle
Neck
Vertebral
end
Demifacet
Head
(capitulum) a
A superior view of a rib showing the joints between it
and a thoracic vertebra
© 2018 Pearson Education, Inc.

17. A posterior view of a typical rib (ribs 2–9) from the right side
Figure 7–24b The Ribs.
Head
Neck
Attachment to
costal cartilage
(sternal end)
Articular facets
Tubercle
Body
Angle
Costal groove b
A posterior view of a typical rib
(ribs 2–9) from the right side
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18. The Thoracic Cage Sternum (breastbone)
A flat bone in anterior midline of thoracic wall
Three parts of the sternum
Manubrium
Body
Xiphoid process
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19. The Thoracic Cage Manubrium Superior portion of sternum
Broad, triangular shape
Articulates with clavicles (collarbones)
Articulates with cartilages of first rib pair
Has a jugular notch, a shallow indentation between clavicular articulations
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20. The Thoracic Cage Sternal body Tongue-shaped Attaches to manubrium
Attaches to costal cartilages of rib pairs 2–7
Xiphoid process
Smallest part of the sternum
Attaches to sternal body
Attaches to diaphragm and rectus abdominis muscle
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21. © 2018 Pearson Education, Inc.

22. Figure 7–23a The Thoracic Cage.
Jugular notch T1
Clavicular articulation 1
Sternum
Manubrium 2 3
Body
True ribs
(ribs 1–7) 4
Xiphoid
process 5
ATLAS: Plate 22b
Costal
cartilages 6 10
T11 7
T12 11
Vertebrochondral
ribs
(ribs 8–10) 12 8 9
False ribs
(ribs 8–12)
Floating ribs
(ribs 11–12) a
An anterior view, showing the
costal cartilages and the sternum
© 2018 Pearson Education, Inc.

23. The Thoracic Cage The developing sternal body
Consists of four separate bones
Fusion is not complete until at least age 25
Leaving transverse lines
The xiphoid process
Last part of sternum to ossify and fuse
Can be broken easily
© 2018 Pearson Education, Inc.