BIOS256 Week 5 Lab Exercise Renal Absorption and Secretion To complete this worksheet, select:
Module: Balancing Fluids Activity: Animations Title: Renal Absorption and Secretion
Introduction
1. Where does renal absorption and secretion occur? Renal Tubules 2. Define what happens during these processes.
a. Absorption: Returns materials to the bloodstream thereby conserving those materials.
b. Secretion: Moves materials from the blood stream into the tubule for eventual disposal. 3. Because of very high glomerular filtration rates, nearly the entire volume of the blood enters the renal tubules every 30 minutes. Obviously, most of it must be reabsorbed to avoid dehydration.
a. What part of the tubule achieves most of the reabsorption?
In the proximal convoluted tubule.
b. Where does further reabsorption and “fine tuning” occur?
In the rest of the nephron. 4. a. Describe paracellular reabsorption.
Paracellular reabsorption is the mechanism where substances diffuse between cells.
b. Describe transcellular reabsorption. Transcellular reabsorption is the mechanism whereby the substances pass through the cell.
c. What kind of transport mechanisms are used for reabsorption?
Transcellular reabsorption is the mechanism whereby the substances pass through the cell. 5. a. Identify two reasons that make secretion important.
* Secretion of hydrogen ions help regulate PH.
* Secretion of other substances eliminates them from the body.
b. What kind of transport mechanisms are used for secretion? Secretion mechancisms only use active transport.
Renal Transport Mechanisms 6. Identify five renal transport mechanisms.
