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

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.

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.

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.

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.

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.

The Thoracic Cage Thoracic cage The skeleton of the chest Consists of Thoracic vertebrae Ribs Costal cartilages Sternum © 2018 Pearson Education, Inc.

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.

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 © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

The Thoracic Cage Ribs 1–7 are true ribs Vertebrosternal ribs Connected to sternum by costal cartilages © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

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.

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.

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 © 2018 Pearson Education, Inc.

The Thoracic Cage Sternum (breastbone) A flat bone in anterior midline of thoracic wall Three parts of the sternum Manubrium Body Xiphoid process © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

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 © 2018 Pearson Education, Inc.

© 2018 Pearson Education, Inc.

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.

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.