Kidney

Question 1

nephron

Answer 1

Question 2

The glomerulus

Answer 2

Question 3

Question 4

Counter current vasa recta

Answer 4

Question 5

Answer 5

Question 6

Where does the filtration step occur in the human kidney?

1. Descending limb of loop of Henle
2. Medulla
3. Glomerulus
4. Thin ascending limb of loop of Henle
5. Distal convoluted tubule

Question 7

What is the force that causes up to 25% of the blood’s plasma volume that arrives at the glomerulus to enter into the Bowman’s Capsule and become the pre-urine filtrate?

1. Osmosis
2. Diffusion
3. Blood pressure
4. Active transport

Answer 7

Blood pressure

Question 8

Why don’t blood cells and large molecules enter Bowman’s capsule?

1. The pores at the glomerulus are too small for them to pass through
2. The blood is moving too rapidly for them to pass through
3. Actually, they do pass through but are later reabsorbed
4. The large proteins, red blood cells and platelets pass through, but the white blood cells are too large

Question 9

After leaving Bowman’s capsule the pre-urine filtrate enters

1. The distal convoluted tubule
2. The descending loop of Henle
3. The thin ascending loop of Henle
4. The thick ascending loop of Henle
5. The proximal convoluted tubule

Question 10

Where in the nephron does the majority of water and solute reabsorption occur?

1. The distal convoluted tubule
2. The descending loop of Henle
3. The thin ascending loop of Henle
4. The thick ascending loop of Henle
5. The proximal convoluted tubule

Question 11

Which molecules are reabsorbed from the pre urine filtrate?

1. Salts
2. Water
3. Vitamins and amino acids
4. Glucose
5. All of the above

Question 12

Where would you predict the largest surface area of transport epithelium would be in the nephron?

1. The distal convoluted tubule
2. The descending loop of Henle
3. The thin ascending loop of Henle
4. The thick ascending loop of Henle
5. The proximal convoluted tubule

Answer 12

The distal convoluted tubule

Question 13

How are solutes reabsorbed in the proximal convoluted tubule?

1. Significantly via active transport (including co-transport)
2. 100% passive diffusion (no ATP required)
3. Only via osmosis

Question 14

How is water reabsorbed in the proximal convoluted tubule?

1. Passively by osmosis and through aquaporins
2. Actively pumped
3. It doesn’t, the proximal convoluted tubule is impermeable to water

Answer 14

Passively by osmosis and through aquaporins

Question 15

Which portion(s) of the loop of Henle is/are impermeable to water?

1. Descending limb
2. Thin ascending limb
3. Thick ascending limb
4. 1 and 3
5. 2 and 3

Question 16

Which portion(s) of the loop of Henle is/are impermeable to NaCl?

Descending limb
Thin ascending limb
Thick ascending limb
A and C
B and C

Answer 16

Descending limb

Question 17

What is reabsorbed from the collecting duct?

1. Salt
2. Water
3. Glucose
4. Amino acids
5. Vitamins

Question 18

Why does more and more water leave the collecting duct as it travels deeper into the medulla?

1. The medulla increases in osmolarity as the collecting duct travels down through it so more and more water follows by osmosis
2. The medulla decreases in osmolarity as the collecting duct travels down through it so more and more water follows by osmosis
3. Active transport of water increases as the collecting duct travels through the medulla

Answer 18

The medulla increases in osmolarity as the collecting duct travels down through it so more and more water follows by osmosis

Question 19

After a good workout you have sweat out a considerable amount of water and salt… how will the body’s osmoregulation be affected?

Question 20

What happens if a person doesn’t make or insert aquaporins in the collecting duct? What would the effect by on the osmolarity of the urine? What symptoms might this person develop?

Question 21

How could high blood pressure damage the kidney? Which structures are likely to be affected most? Why? How would the damage affect the osmolarity and content of the urine?

Question 22

Why would there be glucose in the urine of a person that suffers from diabetes due to ineffective insulin production/use?

Question 23

Drinking coffee or caffeinated beverages increases urine output. Hypothesize two or more possible effects caffeine may have on the nephron or hormones regulating nephrons to result in increased urine output.

Question 24

Drinking beer or alcoholic beverages increases urine output. Hypothesize two or more possible effects alcohol may have on the nephron or hormones regulating nephrons to result in increased urine output.

Answer 24

As with caffeine, think about inhibition of ADH so fewer aquaporins inserted in the collecting duct and less water reabsorbed. May also think about Na transport protein inhibition in the thick ascending limb which would decrease the osmotic gradient in the medulla and therefore draw less water out of the collecting duct.

Question 25

Using nicotine inhibits urine output. Hypothesize two or more possible effects nicotine may have on the nephron or hormones regulating nephrons to result in decreased urine output.

Question 26

Kangaroo rats live in desert conditions and do not drink water. They are under extreme osmotic stress as a result. Would you predict that kangaroo rats have longer or shorter loops of Henle in their nephrons than humans? Why? How would your prediction make the kangaroo rat better adapted for desert conditions?

Question 27

Predict how drinking massive amounts of water would affect urine production and osmolarity in the blood. What parts of the nephron would be most affected? It is possible to die from over hydration – can you hypothesize why?

Question 28

Predict what effects eating large amounts of salt will have on urine production. What parts of the nephron would be most effected? What hormones would be involved? Could a person die from too much sudden salt intake? Hypothesize why. Hypothesize about what happens when ship wrecked people drink seawater out of desperation? ## Footnote

Question 29

Predict what effects not drinking any liquid will have on urine production. What parts of the nephron would be most effected? What hormones would be involved? Hypothesize about what will happen over time. Then imagine that after 48 hours the person receives fluids. How will the nephron and associated hormones respond? ## Footnote

Question 30

Biologists have recently been able to produce mice that lack functioning genes for making aquaporins. How does their urine compare to that of individuals with normal aquaporins? How should the biologists feed and water these mice to keep them most healthy?

Answer 30

They would need to drink a lot of water to compensate for water loss