Question 1

Which of the following best describes the main function of the Loop of Henle in the nephron?

Accepted Answer

It establishes an osmotic gradient in the medulla, allowing for water reabsorption.

Question 2

A patient is given a drug that inhibits active transport in the nephron. Which process would be most directly affected?

Accepted Answer

Reabsorption of glucose and amino acids in the proximal tubule.

Question 3

Which hormone increases water reabsorption in the collecting duct, and through what mechanism?

Accepted Answer

Antidiuretic hormone (ADH) by increasing aquaporin channels.

Question 4

If a person is dehydrated, which hormonal response would you expect to be activated to restore water balance?

Accepted Answer

Increased secretion of ADH, leading to more water reabsorption.

Question 5

Which of the following best explains why filtration in the glomerulus is considered the least selective process in the nephron?

Accepted Answer

Filtration is driven by blood pressure and allows both useful and waste substances to enter the filtrate.

Question 6

A person with a mutation that prevents the production of aquaporin channels in the collecting duct would most likely experience which symptom?

Accepted Answer

Excretion of large volumes of dilute urine.

Question 7

Which of the following statements correctly distinguishes between steroid and peptide hormones?

Accepted Answer

Steroid hormones are lipid-soluble and affect gene expression, while peptide hormones bind to membrane receptors and use signaling pathways.

Question 8

Which process in the nephron is primarily responsible for removing drugs and toxins from the blood?

Accepted Answer

Secretion in the distal tubule.

Question 9

A marine fish living in seawater is most likely an osmoconformer. What does this mean for its internal osmolarity?

Accepted Answer

Its internal osmolarity matches that of the surrounding seawater.

Question 10

Which of the following best describes the difference between the endocrine and nervous systems?

Accepted Answer

The endocrine system uses hormones for slow, long-lasting effects, while the nervous system uses electrical signals for rapid, short-term responses.

Question 11

Which of the following scenarios best illustrates the concept of an osmoregulator?

Accepted Answer

A freshwater fish actively pumps ions into its body to maintain internal osmolarity different from its environment.

Question 12

Which of the following is a correct sequence of nephron structures through which filtrate passes?

Accepted Answer

Bowman's capsule → proximal tubule → Loop of Henle → distal tubule → collecting duct

Question 13

Which hormone system is primarily responsible for increasing both sodium and water reabsorption to help maintain blood pressure?

Accepted Answer

Renin-angiotensin-aldosterone system (RAAS)

Question 14

Epinephrine can cause different effects in different tissues. What is the most likely explanation for this phenomenon?

Accepted Answer

Different tissues have different types of epinephrine receptors.

Question 15

Which of the following best describes the role of nitric oxide as a signaling molecule?

Accepted Answer

It acts as a local regulator and gas signaling molecule over short distances.

Question 16

A patient with high blood pressure is found to have excessive aldosterone secretion. Which of the following is a likely consequence?

Accepted Answer

Increased sodium and water reabsorption, leading to higher blood volume.

Question 17

Which process is driven by a concentration gradient and does NOT require ATP?

Accepted Answer

Diffusion

Question 18

Which of the following best explains why peptide hormones cannot directly affect gene expression?

Accepted Answer

They are not lipid-soluble and cannot cross the cell membrane to enter the nucleus.

Question 19

Which of the following is the primary function of reabsorption in the nephron?

Accepted Answer

To return useful substances such as glucose and ions back to the blood.

Question 20

A person with a defect in the RAAS pathway would most likely have difficulty with which physiological process?

Accepted Answer

Maintaining blood pressure and sodium balance.

Osmoregulation, Excretion, and the Endocrine System

Study Guide - Practice Questions