also produce hormones and thus function as parts of theendocrine system.The digestive system includes the mouth, tongue, teeth,salivary glands, pharynx, esophagus, stomach, liver,gallbladder, pancreas, small intestine, and large intestine.Chapter 18 discusses nutrition and metabolism,considering the fate of foods in the body.The organs of the respiratory system (fig. 1.15) take air inand out and exchange gases between the blood and the air.More specifically, oxygen passes from air within the lungsinto the blood, and carbon dioxide leaves the blood andenters the air. The nasal cavity, pharynx, larynx, trachea,bronchi, and lungs are parts of this system, which isdiscussed in chapter 19.The urinary system (Hg. 1.15) consists of the kidneys,ureters, urinary bladder, and urethra. The kidneys removewastes from blood and assist in maintaining the body*swater and electrolyte balance. The product of theseactivities is urine. Other portions of the urinary systemstore urine and transport it outside the body. Chapter 20discusses the urinary system.
