Bios256 Week 5

1244 Words Dec 14th, 2014 5 Pages
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
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The major role of primary active transport is to move sodium from the cytosol of the tubule cell into the surrounding interstitial fluid surrounding the capillary.

b. Describe the role of primary active transport with regard to potassium (K+) and hydrogen (H+) ion movement. As a secondary function it provides the driving force to move potassium and hydrogen ions from the interstitial fluid to the filtrate.

c. Why is Na+ movement important with regard to movement across the membrane? The movement of sodium ions via active transport is to generate an electrochemical gradient between the filtrate and the interstitial fluid.

8. a. The energy stored in the sodium ion electrochemical gradient is used to transport other molecules back toward the bloodstream (reabsorption). What nutrients are transported in this fashion? Glucose, amino acids and other solutes being recovered from the filtrate. b. How does the sodium gradient affect hydrogen ion movement? Active transport requires chemical energy because it is the movement of biochemicals from areas of lower concentration to areas of higher concentration.

9. Describe the role of transporter proteins with regard to nutrient movement.

It goes from high to low concentration, in order to maintain equilibrium in the cells. Does not require cellular energy.

10. Describe ion movement through or between the cell membranes into the interstitial…

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