ACTIVITY 1: The Effect of Arteriole Radius on Glomerular Filtration Answers 1. According to your lab manual, in humans the glomerular filtration rate (GFR) ranges from _____ to _____ ml/minute. 80 140
2. When the radii of both the afferent arteriole and efferent arteriole were set at 0.45mm, the GFR was approximately ______ ml/minute. a. 40
d. 120 C.
3. True or False: Drinking a lot of caffeine (coffee or cola) leads to an increased urine volume. This might result from a decrease in the radius of the efferent arteriole. True 4. What are two primary functions of the kidney? Excretion-filters water and solutes in the blood, the kidneys are able to excrete excess water Regulation- regulates plasma osmolarity which is the concentration of solution expressed as osmoles of solute per liter of solvent, plasma volume, body's acid-base balance, and body's electrolyte balance. 5. What are the components of the renal corpuscle? Bowman's capsule- renal corpuscle consist of a ball of capillaries called glomerulus and enclosed by a fluid-filled capsule called Bowman's capsule Glomerular Capillaries- this is another name for the renal corpuscle. An afferent arteriole supplies the blood to the glomerulus. The blood flows through the glomerular capillaries, protein-free plasma filters into the Bowman's capsule, and known as the glomerular filtration. The afferent arteriole then drains glomerulus of the remaining blood. 6. Starting at the renal corpuscle, list the components of the renal tubule as they are encountered by filtrate. 1.Proximal convoluted tubule 2.Loop of Henle (U-shaped hairpin loop)
3.Distal convoluted tubule- before emptying into a collecting duct, from collecting duct, filtrate flows and collects in the minor calyces. 7. Describe the effect of decreasing the afferent arteriole radius on glomerular capillary pressure and filtration rate. By decreasing the afferent arteriole radius, this increases the glomerular filtration rate and pressure increases. 8. Describe the effect of increasing the afferent arteriole radius on glomerular capillary pressure and filtration rate. Increasing afferent arteriole radius, glomerular capillary pressure and filtration rate increases. 9. Describe the effect of decreasing the efferent arteriole radius on glomerular capillary pressure and filtration rate. Efferdent arteriole radius is decreased, glomerular filtration rate would increase. 10. Describe the effect of increasing the efferent arteriole radius on glomerular capillary pressure and filtration rate. Efferent arteriole radius if increased, the glomerular filtration rate would decrease. ACTIVITY 2: The Effect of Pressure on Glomerular Filtration 11. True or False: In humans, glomerular capillaries can filter as much as 180 liters of filtrate in 24 hours. True 12. In this simulation, when the radius of the afferent arteriole was 50mm, the radius of the efferent arteriole was 0.45mm, and the beaker pressure was set to 100mmHg, the GFR was approximately _____ ml/min. 158.20 13. When the valve between the collecting duct and the urinary bladder was closed and when the beaker pressure was 100mmHg, the GFR was approximately _____ ml/min and the urine volume was approximately ______ ml. a. 100; 100
b. 110; 50
c. 60; 0
d. 110; 0 D.
14. As the systemic blood pressure increased, what happened to the glomerular capillary pressure and the GFR? As the systemic blood pressure increased, the glomerular capillary pressure and GFR increased. 15. Compare the urine volume in your baseline data with the urine volume as you increased the systemic blood pressure. Urine volume was increased as systemic blood pressure increased. 16. How could the change in urine volume with the increase in blood pressure be viewed as being beneficial to the...