PhysioEx Exercise 9 Activity 3

11/12/23, 10:29 PM PhysioEx Exercise 9 Activity 3 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex9/act3/ 1/4 PhysioEx Lab Report Exercise 9: Renal System Physiology Activity 3: Renal Response to Altered Blood Pressure Name: Jonathan Ascencio Date: 12 November 2023 Session ID: session-2de4247b-49c2-4464-7944-012ea883e1a4 Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. Experiment Results Predict Question Stop & Think Questions If all other variables are kept constant, how does the afferent arteriole radius affect the rate of glomerular filtration? You correctly answered: An increased afferent arteriole radius will increase the rate of glomerular filtration. 1 If all other variables are kept constant, how does the efferent arteriole radius affect the rate of glomerular filtration? You correctly answered: A decreased efferent arteriole radius will increase the rate of glomerular filtration. 2 If all other variables are kept constant, how does blood pressure affect the rate of glomerular filtration? You correctly answered: Blood pressure directly affects glomerular filtration rate. 3 In the absence of other renal processes (including tubular reabsorption and secretion), more glomerular filtration leads to a larger urine volume. You correctly answered: true. 4 Predict Question: What will happen to the glomerular capillary pressure rate and glomerular filtration rate if both of these arteriole radii changes are implemented simultaneously with the low blood pressure condition? Your answer: Glomerular filtration rate and pressure will rise above baseline values. 1

11/12/23, 10:29 PM PhysioEx Exercise 9 Activity 3 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex9/act3/ 2/4 Experiment Data Afferent Radius (mm) Efferent Radius (mm) Beaker Press. (mm Hg) Glomerular Press. (mm Hg) Glom. Filt. Rate (ml/min) Urine Volume (ml) 0.10 0.30 70 44.44 0.00 0.00 0.30 0.35 70 45.20 2.50 43.60 0.60 0.35 70 55.58 131.15 245.57 Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. If blood pressure were to drop (for example, as the result of blood loss), what changes in the nephron would allow the kidney to maintain its normal glomerular filtration rate? You correctly answered: afferent arteriole dilation and efferent arteriole constriction. 1 Comparing the glomerular filtration rate and glomerular capillary pressure with the baseline values (from the first run), how effective was the increased afferent arteriole radius in compensating for the low blood pressure? You correctly answered: The afferent arteriole dilation returned the low glomerular capillary pressure and filtration rate almost to baseline values. 2 Comparing the glomerular filtration rate and glomerular capillary pressure with the baseline values (from the first run), how effective was the decreased efferent arteriole radius in compensating for the low blood pressure? You correctly answered: The efferent arteriole constriction improved the low glomerular capillary pressure and filtration rate marginally. 3 If all other variables are kept constant, when blood pressure decreases, glomerular filtration You correctly answered: decreases. 1 If the efferent arteriole radius decreases in response to a decrease in blood pressure, then glomerular filtration You correctly answered: remains approximately the same. 2 If all other variables are kept constant, when the efferent arteriole radius decreases, glomerular filtration You correctly answered: increases. 3

11/12/23, 10:29 PM PhysioEx Exercise 9 Activity 3 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex9/act3/ 4/4 The afferent arteriole dilation is the most effective at compensating for the effect of low blood pressure on the glomerular filtration rate. This adjustment is able to keep the glomerular filtration rate and blood pressure at normal values. In the body, how does a nephron maintain a near-constant glomerular filtration rate despite a constantly fluctuating blood pressure? Your answer: The nephron can maintain a near-constant glomerular filtration rate despite fluctuating blood pressure because of its ability to dilated and constrict the afferent and efferent arteriole. 5