CO SCI 136 Lecture Notes - Lecture 10: Brainstem, Mechanoreceptor, Orexin
Document Summary
Regulation of the fluid that bathes our cells is part of a process called homeostasis. This chapter discusses the means by which we mammals achieve homeostatic control of the vital characteristics of our extracellular fluid through our ingestive behavior: intake of food, water, and minerals such as sodium. Satiety mechanisms monitor the activity of the correctional mechanism (in this case, drinking), not the system variables themselves. When a sufficient amount of drinking occurs, the satiety mechanisms stop further drinking in anticipation of the replenishment that will occur later. Fluid balance: the body contains four major fluid compartments: one compartment of intracellular fluid and three compartments of extracellular fluid. Two-thirds of the body"s water is contained in the intracellular fluid, the fluid portion of the cytoplasm of cells. If the interstitial fluid loses water (becomes more concentrated, or hypertonic), water will be pulled out of the cells.
