142 Anatomy & Physiology Essentials Copyright Goodheart-Willcox Co., Inc. Costal cartilage Jugular notch Floating ribs False ribs True ribs 1 2 3 4 5 6 7 8 9 10 11 12 Manubrium Sternal angle Xiphisternal joint Xiphoid process Body Sternum Clavicle © Body Scientific International Figure 5.19 The thoracic cage. SECTION 5.3 REVIEW Mini-Glossary atlas the first cervical vertebra specialized to provide the connection between the occipital bone of the skull and the spinal column axial skeleton the central portion of the skeletal system, consisting of the skull, spinal column, and thoracic cage axis the second cervical vertebra specialized with an upward projection called the odontoid process, on which the atlas rotates cervical region the first seven vertebrae, comprising the neck coccyx the four vertebrae at the base of the spine that are fused to form the tailbone cranium collective term for the fused, flat bones surrounding the back of the head facial bones bones of the face fontanel an opening in the infant skull through which the baby’s pulse can be felt these openings enable compression of the skull during birth and brain growth during late pregnancy and early infancy intervertebral discs fibrocartilaginous cushions between vertebral bodies that allow bending of the spine and help to create the normal spinal curves lumbar region five vertebrae comprising the low back region of the spine mandible jaw bone maxillary bones two fused bones that form the upper jaw, house the upper teeth, and connect to all other bones of the face, with the exception of the mandible median sacral crest prominent elevation formed by the fused spinous processes of the upper four sacral vertebrae sacral canal continuation of the vertebral canal in the sacral region sacral hiatus prominent opening at the inferior end of the sacral canal sacrum collective term for five fused vertebrae that form the posterior of the pelvic girdle skull the part of the skeleton composed of all of the bones of the head sternum breastbone sutures joints in which irregularly grooved, articulating bone sheets join closely and are tightly connected by fibrous tissues thoracic cage the bony structure surrounding the heart and lungs in the thoracic cavity composed of the ribs, sternum, and thoracic vertebrae thoracic region the 12 vertebrae located in the middle of the back vertebra one of the bones making up the spinal column (continued)