Q: A patient has a plasma inulin concentration of $$0.5\ \text{mg/mL}$$, urine inulin concentration of $$50\ \text{mg/mL}$$, and a urine flow rate of $$2\ \text{mL/min}. $$What is the clearance of inulin?

$$C = \frac{50 \times 2}{0.5} = 200\ \text{mL/min}$$

Q: What is the normal osmolarity of blood plasma?

Approximately $$300\ \text{mOsm}$$

Question 1

Which of the following is NOT one of the six primary functions of the kidneys?

Accepted Answer

Regulation of blood glucose levels

Question 2

A patient presents with glycosuria (glucose in the urine). Which mechanism best explains this finding?

Accepted Answer

Saturation of glucose transporters in the proximal tubule

Question 3

Which equation correctly calculates renal clearance ($$C) of a $$substance?

Accepted Answer

$$C = \frac{U 	imes V}{P}$$

Question 4

Which structure is responsible for preventing plasma proteins from entering the filtrate during glomerular filtration?

Accepted Answer

All of the above

Question 5

If the glomerular filtration rate (GFR) increases due to a rise in blood pressure, which autoregulatory mechanism will counteract this change?

Accepted Answer

Myogenic response causing afferent arteriole constriction

Question 6

Which segment of the nephron is primarily responsible for the reabsorption of glucose?

Accepted Answer

Proximal tubule

Question 7

A patient has a plasma inulin concentration of $$0.5\ 	ext{mg/mL}$$, urine inulin concentration of $$50\ 	ext{mg/mL}$$, and a urine flow rate of $$2\ 	ext{mL/min}. $$What is the clearance of inulin?

Accepted Answer

$$C = \frac{50 	imes 2}{0.5} = 200\ 	ext{mL/min}$$

Question 8

Which pressure does NOT contribute to the net glomerular filtration pressure?

Accepted Answer

Peritubular capillary hydrostatic pressure

Question 9

Which of the following best describes secondary active transport in the nephron?

Accepted Answer

Glucose reabsorption via sodium-glucose cotransporter (SGLT)

Question 10

What is the normal osmolarity of blood plasma?

Accepted Answer

Approximately $$300\ 	ext{mOsm}$$

Question 11

Which of the following statements about excretion and clearance is TRUE?

Accepted Answer

Clearance measures the volume of plasma from which a substance is completely removed per unit time, while excretion measures the amount of substance eliminated in urine.

Question 12

Which of the following is a reason why peritubular capillary pressure favors reabsorption?

Accepted Answer

Low hydrostatic pressure and high oncotic pressure in peritubular capillaries

Question 13

Which of the following is TRUE regarding the volume of fluid filtered and excreted by the kidneys daily?

Accepted Answer

About 180 L is filtered, but only 1.5 L is excreted as urine

Question 14

Which of the following best describes the process of micturition?

Accepted Answer

A reflex involving relaxation of the internal sphincter and contraction of the bladder wall

Question 15

Which of the following is NOT a function of the juxtaglomerular apparatus?

Accepted Answer

Filtration of plasma proteins

Question 16

Which of the following is an example of tertiary indirect active transport in the nephron?

Accepted Answer

Organic anion secretion using the OAT transporter

Question 17

Which of the following best explains why filtration is so high in the kidneys despite almost equally high reabsorption?

Accepted Answer

The kidneys filter large volumes to rapidly remove waste and regulate homeostasis, but reabsorb most useful substances to prevent loss.

Question 18

Which of the following is TRUE regarding the percentage of plasma filtered and excreted?

Accepted Answer

About 20% of plasma is filtered into Bowman's capsule, but less than 1% is excreted as urine.

Question 19

Which of the following best describes the role of the macula densa in tubuloglomerular feedback?

Accepted Answer

Detects increased NaCl in filtrate and signals afferent arteriole constriction to decrease GFR

Chapter 19 – The Kidneys: Structure, Function, and Physiology

Study Guide - Practice Questions

Study Guide - Flashcards