Human Anatomy and Physiology : Excretory Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

varsity tutors app store varsity tutors android store

Example Questions

← Previous 1 3

Example Question #1 :Help With Nephron Physiology

Which of the following nephron sections is primarily associated with the absorption of sodium ions and the secretion of potassium ions?

Possible Answers:

Loop of Henle

Glomerulus

Distal convoluted tubule

Proximal convoluted tubule

Correct answer:

Distal convoluted tubule

Explanation:

The distal convoluted tubule follows the loop of Henle in the nephron structure. In addition to lowering the filtrate concentration, it is also used to reabsorb sodium ions and secrete potassium ions. Aldosterone acts on the distal tubule and further stimulates these two actions.

Example Question #1 :Help With Nephron Physiology

Which section of the nephron does not result in a change in filtrate concentration?

Possible Answers:

Loop of Henle

Collecting duct

Proximal convoluted tubule

Distal convoluted tubule

Correct answer:

Proximal convoluted tubule

Explanation:

肾单位是由多个部分,制作h are used to alter the solute composition and concentration of the filtrate. The first section is the proximal convoluted tubule. While the solute composition of the filtrate will change due to reabsorption and secretion of specific solutes, the overall concentration does not change. In the proximal convoluted tubule, filtrate is kept isotonic with blood.

Example Question #3 :Help With Nephron Physiology

How does antidiuretic hormone (ADH) affect the nephron?

Possible Answers:

ADH makes the loop of Henle permeable to water, concentrating the urine

ADH makes the collecting duct impermeable to water, concentrating the urine

ADH makes the collecting duct permeable to water, concentrating the urine

ADH makes the collecting duct permeable to water, diluting the urine

ADH makes the loop of Henle impermeable to water, concentrating the urine

Correct answer:

ADH makes the collecting duct permeable to water, concentrating the urine

Explanation:

The collecting duct of a nephron is normally impermeable to water. In the presence of antidiuretic hormone (ADH), aquaporin proteins are inserted, making the collecting duct permeable to water. Water then diffuses into the medulla due to the solute concentration of the surrounding tissues, generated from ion reabsorption in the loop of Henle. This loss of water from the urine makes it more concentrated.

Example Question #2 :Help With Nephron Physiology

The glomerulus is primarily associated with which function?

Possible Answers:

Ion reabsorption

Filtration

Protein reabsorption

Secretion

Active transport

Correct answer:

Filtration

Explanation:

The glomerulus is a capillary structure associated with the first section of the nephron where blood enters the renal corpuscle. The glomerulus is responsible for filtering fluid, plasma, and dissolved particulates out of circulation and into Bowman's capsule, resulting in a primary filtrate that will go through the rest of the nephron.

Example Question #1 :Excretory And Digestive Physiology

Which of the following is true regarding the nephron?

Possible Answers:

Water is reabsorbed in the distal convoluted tubule

黄斑窝sa cells are found within the lumen of the distal convoluted tubule

All of these

Water is reabsorbed in the descending limb of the loop of Henle

Correct answer:

All of these

Explanation:

所有答案的选择是正确的。黄斑窝sa cells are sensitive to changes in concentration of sodium chloride. A decrease in concentration ofis detected, which stimulates the macula densa cells to secrete paracrine factors that ultimately increase the pressure in the glomerulus, and thus the glomerular filtration rate, and stimulates the release of renin, which ultimately increases blood pressure, volume and cardiac output.

Example Question #6 :Help With Nephron Physiology

The major reabsorption of water, ions, and other important molecules such as glucose occurs in what part of the nephron?

Possible Answers:

Vasa recta

Proximal convoluted tubule

Distal convoluted tubule

Collecting duct

Glomerulus

Correct answer:

Proximal convoluted tubule

Explanation:

After filtration of the blood through the glomerulus, approximately 70% of the water and salts is reabsorbed in the proximal convoluted tubule. Additionally, 100% of the glucose is reabsorbed here in a healthy, functioning nephron. The lumenal cells of the proximal convoluted tubule are lined with microvilli and are called brush border cells. Histology of the proximal convoluted tubule is indicative of these structures and the proximal convoluted tubule's lumen can be seen as "crowded" with epithelial surface area, which is distinct from the lumen of the distal convoluted tubule.

Example Question #7 :Help With Nephron Physiology

ADH (antidiuretic hormone, also known as vasopressin) has which of the following effects on nephron function?

Possible Answers:

Reabsorption of water decreases as a result of additional aquaporins being placed in the distal convoluted tubule and collecting duct

Reabsorption of water increases as a result of additional aquaporins being placed in the distal convoluted tubules and collecting duct

Reabsorption of water increases as a result of additional aquaporins being placed in the proximal convoluted tubule

Reabsorption of water increases as a result of more ATP-dependent water pumps in the distal convoluted tubule and collecting duct

Reabsorption of water decreases as a result of less aquaporins being placed in the proximal convoluted tubule

Correct answer:

Reabsorption of water increases as a result of additional aquaporins being placed in the distal convoluted tubules and collecting duct

Explanation:

ADH acts upon the collecting ducts and distal convoluted tubules of nephrons to increase water reabsorption. It causes an increase in the number of aquaporins in order to allow for this.

Example Question #2 :Excretory And Digestive Physiology

Concentration and dilution of urine is a major responsibility of what part of the nephron?

Possible Answers:

Proximal convoluted tubule

Loop of Henle

Glomerulus

Distal convoluted tubule

Collecting duct

Correct answer:

Loop of Henle

Explanation:

As filtrate passes through the Loop of Henle, the level of concentration of the fluid that will become urine is determined by the length of the loop of Henle (how far into the medulla it dips) and, the osmolality of the medulla. Depending on the levels of circulating hormones, the distal convoluted tubule and collecting duct could be the part of the nephron that determines the concentration of the urine, but to a lesser extent than the length of the loop of Henle.

Example Question #9 :Help With Nephron Physiology

The descending limb of the loop of Henle is__________.

Possible Answers:

water permeable

water permeable and solute impermeable

water and solute impermeable

solute impermeable

solute permeable

Correct answer:

water permeable and solute impermeable

Explanation:

The descending limb of the loop of Henle is both water permeable and solute impermeable. These properties of the limb allow the filtrate moving through the nephron to become either concentrated or diluted depending on the circumstance.

Example Question #1 :Help With Nephron Physiology

The vessels surrounding the Loop of Henle are called__________.

Possible Answers:

renal vein

afferent arterioles

vasa recta

peritubular capillaries

efferent arterioles

Correct answer:

vasa recta

Explanation:

The afferent and efferent arterioles are located near the glomerulus and control the glomerular filtration rate by constriction and dilation. The peritubular capillaries wind around the proximal convoluted tubule and the distal convoluted tubule to allow for reabsorption and secretion there. The vasa recta on the other hand wind around the loop of Henle and maintain countercurrent multiplication.

← Previous 1 3
Learning Tools by Varsity Tutors