BIOL 1840U Lecture Notes - Proximal Tubule, Epithelium, Sodium Chloride
Document Summary
Overview of renal system: functions of the human kidney. Main function: maintain volume and solute concentration in extracellular fluid. Also, excrete substances, make glucose, nh3, and hormones. Fluid is compartmentalized in the human body. Intracellular fluid: holds about 2/3 of body fluid. Extracellular fluid: holds about 1/3 of body fluid. Water is freely exchangeable among all body compartments, but distribution is controlled: Divided into interstitial, intravascular, and transcellular fluids. By solute concentration (a colligative property), and. For ions, by ion pumps (a transporter) and membrane potential. Intracellular volume is controlled by each cell by regulating solute concentration. E. g. by regulating na and k concentration via the na/k pump. Extracellular volume and solute concentration is controlled by epithelia. Outflow is controlled by kidney (and sweat) In physiology, steady state about a set point is called homeostasis. Maintaining homeostasis requires sensors, mediators, and effectors.
