128 Anatomy & Physiology Essentials Copyright Goodheart-Willcox Co., Inc. and flushes out metabolic waste products with an influx and outflow of fluid. Because maintaining a fixed body position curtails this pumping action, sitting in one position for a long period of time can negatively affect disc health. aging reduce the water retention capability of the discs, accounting for diminished standing height in elderly individuals. Because the discs receive no blood supply, they must rely on changes in posture and body position to produce a pumping action that brings in nutrients Lateral Views Cervical vertebrae Thoracic vertebrae Lumbar vertebrae Spinous process Spinous process Spinous process Spinous process Inferior articular facet Superior Views Spinous process Inferior articular process Inferior costal facet Spinous process Inferior articular facet Superior costal facet Lamina Lamina Body Body Body Pedicle Transverse foramen Vertebral foramen Vertebral foramen Vertebral foramen Transverse process Transverse process Transverse process Transverse costal facet Transverse costal facet Superior articular facet Superior articular facet Superior articular process Superior articular facet A B C © Body Scientifi c International Figure 5.17 Superior and left lateral views of typical cervical (A), thoracic (B), and lumbar (C) vertebrae.