An Introduction to the Axial Skeleton Structures of Bones Contacts with other bones (bone markings; marks) Areas of muscle and ligament attachment Openings for nerves and blood vessels © 2015 Pearson Education Inc.

7-1 The Axial Skeleton The Axial Skeleton Forms the of the body Has bones The 8 cranial bones 14 facial bones Bones associated with the skull 6 auditory The hyoid bone © 2015 Pearson Education Inc.

7-1 The Axial Skeleton The Axial Skeleton The vertebral column (singular  vertebra) The sacrum The coccyx The cage 24 ribs The sternum © 2015 Pearson Education Inc.

Figure 7-1a The Axial Skeleton. SKELETAL SYSTEM 206 APPENDICULAR SKELETON AXIAL SKELETON 80 (see Figure 8-1) 8 Cranium Skull 14 Face Skull and associated bones Auditory ossicles 29 6 Associated bones 1 Hyoid 1 Sternum Thoracic cage 25 24 Ribs 24 Vertebrae 1 Sacrum 26 Vertebral column 1 Coccyx 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.

Figure 7-1b The Axial Skeleton. Skull Cervical vertebrae Sternum Thoracic vertebrae Ribs Costal cartilages Lumbar vertebrae Sacrum Coccyx Anterior (left) and posterior (right) views of the axial skeleton. The individual bones associated with the skull are not visible. b

7-1 The Axial Skeleton Functions of the Supports and protects organs in body cavities Attaches to muscles of head, neck, and trunk Performs respiratory movements Stabilizes parts of © 2015 Pearson Education Inc.

7-2 The Skull The Skull : The brain Entrances to respiratory system Entrance to digestive system 22 bones 8 Form the braincase, or cranium 14 Protect and support entrances to digestive and respiratory tracts © 2015 Pearson Education Inc.

Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 1 of 3). FACE 14 CRANIUM 8 ASSOCIATED BONES 7 7 Maxillae 2 Occipital bone 1 Palatine bones 2 Parietal bones 2 1 Hyoid bone 1 Auditory ossicles enclosed in temporal bones (detailed in Chapter 17) 6 Nasal bones 2 Frontal bone Inferior nasal conchae 2 Temporal bones 2 Zygomatic bones 2 Sphenoid 1 Lacrimal bones 2 Ethmoid 1 Vomer 1 Mandible 1 Hyoid bone

Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 2 of 3). Frontal bone Parietal bone Nasal bone Lacrimal bone Vomer Temporal bone Zygomatic bone Ethmoid Maxilla Sphenoid Occipital bone Mandible Facial bones protect and support the entrances to the digestive and respiratory tracts. Cranial bones surround and protect the brain.

Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 3 of 3). Auditory ossicles