Chapter 5 Axial Skeleton Essentials of Human Anatomy & Physiology Seventh Edition Elaine N. Marieb Chapter 5 Axial Skeleton Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Axial Skeleton Forms the longitudinal part of the body Divided into three parts Skull Vertebral column Bony thorax Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Axial Skeleton Figure 5.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Skull Two sets of bones Bones are joined by sutures Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint There are eight flat bones that form the cranium. They are all single bones except for two paired bones; the parietal and the temporal bones. There are four main sutures to remember: Coronal Suture Sagittal Suture Occipital Suture Lamdoid Suture Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Skull The temporal bone has six points of interest for you to remember: External auditory meatus Styloid process Zygomatic process Mastoid process Jugular foramen Carotid canal Figure 5.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Skull There are fourteen bones that compose the face. Twelve are paired; the mandible and vomer are the single bones. Figure 5.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Human Skull, Superior View Figure 5.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Human Skull, Inferior View Foramen Magnum is found in the occipital bone of the skull. Figure 5.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity Figure 5.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Paranasal Sinuses Functions of paranasal sinuses Lighten the skull Give resonance and amplification to voice Figure 5.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Remember the first bullet. It also serves as an attachment for neck muscles responsible for moving your larynx up and down when swallowing. Figure 5.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Fetal Skull The fetal skull is large compared to the infants total body length Figure 5.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Fetal Skull Fontanelles – fibrous membranes connecting the cranial bones Allow the brain to grow Convert to bone within 24 months after birth Figure 5.13 Slide 5.27b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings