The Nephron

Question 1

Parts of renal corpuscle

Answer 1

Glomerulsu and Bowmann’s capsule

Question 2

Portions of the renal tubule

Answer 2

Proximal convoluted tubule, Loop of Henle, distal convoluted tubule.

Question 3

Purpose of the renal tubules

Answer 3

Secretion and reabsorption

Question 4

Purpose of the collecting ducts

Answer 4

Making final adjustments to urine concentrations.

Question 5

Podocytes

Answer 5

Structures which filter substances in a similar way to fenestrations.

Question 6

Juxtaglomerular apparatus

Answer 6

Lies outside the Bowmann’s capsule and the glomerular apparatus.

Question 6

Filtration membrane

Answer 6

Membrane formed by fenestrations, the basement membrane and podocytes. Permits rapid movement from capillaries to capsule.

Question 7

Location of the juxtaglomerular apparatus

Answer 7

The junction between the afferent and efferent arterioles.

Question 8

Macula densa

Answer 8

Part of the juxtaglomerular apparatus which is found in the wall of the DCT. It monitors the fluid composition.

Question 9

Purpose of macula densa

Answer 9

Releases paracrine signals in response to sodium.

Question 10

How does the macula densa monitor fluid concentration?

Answer 10

It has a single, non-motile cilium that waves in moving fluid.

Question 11

Juxtaglomerular cell

Answer 11

Cell in the JGA which is a smooth muscle cell and lines the afferent arteriole. Relaxes and contracts in response to ATP or adenosine.

Question 12

Response of JG cells to high sodium

Answer 12

Cell contracts, decreasing arteriole diameter and filtration rate. Leads to water retention.

Question 13

Response of JG cells to low sodium

Answer 13

Cell relaxes, increasing arteriole diameter and filtration rate. Leads to water excretion.

Question 14

Effects of renin

Answer 14

Vasoconstriction

Question 15

Is the collecting duct a part of the nephron?

Answer 15

No

Question 16

Lining of the collecting ducts

Answer 16

Squamous epithelium with receptors for antidiuretic hormone

Question 17

Response of collecting ducts to antidiuretic hormone

Answer 17

Insert aquaporins to allow water to pass back out into the the interstitial space.

Question 18

Glomerular filtration rate

Answer 18

Volume of filtrate formed by the kidneys each minute.

Question 19

How much blood passes through the kidney each minute?

Answer 19

1L

Question 20

How much filtrate is returned back to circulation?

Answer 20

99%

Question 21

What influences glomerular filtration rate?

Answer 21

Hydrostatic pressure and colloidal osmotic pressure on either side of the capillary membrane.

Question 22

Net filtration pressure (NFP)

Answer 22

Sum of osmotic and hydrostatic pressure in the nephron

Question 23

Where does reabsorption occur?

Answer 23

The PCT, Loop of Henle, DCT and collecting ducts.

Question 24

Which hormones control glomerular filtration

Answer 24

Antidiuretic hormone, aldosterone and renin

Question 25

Methods of transport across the filtration membrane

Answer 25

Active transport, diffusion, secondary active transport, osmosis

Question 26

Which solutes are reabsorbed in the nephron?

Answer 26

Calcium, sodium, glucose, amino acids

Question 27

Which solutes are generally excreted by the nephron?

Answer 27

Potassium, urea, ammonia and creatinine.

Question 28

Substances reabsorbed in the PCT

Answer 28

Water, sodium, potassium, glucose, amino acids, vitamins

Question 29

Effect of aldosterone on the DCT and collecting ducts

Answer 29

Increase the amount of sodium/potassium pumps.

Question 30

Where do the final adjustments to urine concentration occur?

Answer 30

The collecting ducts

Question 31

What do intercalated cells do?

Answer 31

THe regulate blood pH.

Question 32

How do intercalated cells work?

Answer 32

THe reabsorb potassium and bicarbonate while secreting protons into the filtrate. This increase urine acidity.

Question 33

Innervation to the blood vessels in the kidney

Answer 33

Sympathetic nerves from the celiac plexus and splenic nerves.

Question 34

Where does plasma filtration occur?

Answer 34

The renal corpuscle

Question 35

The ascending loop of Henle is impermeable to which substance?

Answer 35

Water

Question 36

Waste product of purine nucleotide digestion

Answer 36

Uric acid