Nephrology Physiology

Question 1

What are the main roles of the kidney?

Answer 1

Regulation of extracellular fluid volume and blood pressure
Regulation of osmolarity
Maintaining ion balance
pH regulation
Waste excretion
Hormone production
Gluconeogenesis

Question 2

What is the functional unit of the kidney?

Answer 2

Nephron

Question 3

What are the parts of the nephron?

Answer 3

Bowman's capsule
Proximal convoluted tubule
Descending/ascending limb of loop of Henle
Distal convoluted tubule
Collecting duct

Question 4

What is Bowman’s capsule?

Answer 4

The space at the head of the nephron

Question 5

What is the glomerulus?

Answer 5

Capillaries found in the Bowman’s capsule

Question 6

Podocytes are important in which renal process?

Answer 6

Glomerular filtration

Question 7

What do mesangial cells do?

Answer 7

Contract to regulate blood flow

Question 8

What do granular cells secrete?

Answer 8

Renin

Question 9

What are the four major renal processes?

Answer 9

Glomerular filtration
Tubular reabsorption
Tubular secretion
Excretion

Question 10

What happens in glomerular filtration?

Answer 10

Substances in the glomerulus get filtered into the nephron

Question 11

What happens in tubular reabsorption?

Answer 11

Substances previously filtered are reabsorbed into blood

Question 12

What happens in tubular secretion?

Answer 12

Substances are secreted from the blood into the nephron

Question 13

What happens in excretion?

Answer 13

Waste products are removed in the urine

Question 14

What percentage of plasma is filtered in the glomerulus?

Answer 14

20%

Question 15

Of the 20% plasma filtered in the glomerulus, how much is reabsorbed back into the blood?

Answer 15

19%

Question 16

The podocytes help to form what membrane?

Answer 16

Filtration membrane

Question 17

What is the function of the filtration membrane?

Answer 17

Prevent large negatively charged molecules being filtered

Question 18

What pressure favours filtration?

Answer 18

Glomerular filtration pressure

Question 19

What pressures oppose filtration?

Answer 19

Bowman’s capsule pressure

Glomerular oncotic pressure

Question 20

What is the value of net filtration pressure?

Answer 20

10 mm Hg

Question 21

What is glomerular filtration rate?

Answer 21

The volume of fluid filtered into Bowman’s capsule per unit time

Question 22

What is the normal value of glomerular filtration rate?

Answer 22

125 ml/min

Question 23

What is the equation of glomerular filtration rate?

Answer 23

GFR = net filtration pressure x Kf

Question 24

How does vasoconstriction of the afferent arteriole affect the GFR?

Answer 24

Decreases glomerular hydrostatic pressure decreasing GFR

Question 25

What effect does vasodilation of the afferent arteriole have on GFR?

Answer 25

Increases glomerular hydrostatic pressure increasing GFR

Question 26

What substances are reabsorbed in the proximal convoluted tubule?

Answer 26

Na, Cl, H, glucose, amino acids and water

Question 27

What substance is reabsorbed in the descending limb of loop of Henle?

Answer 27

Water

Question 28

What substances are reabsorbed in the ascending limb of loop of Henle?

Answer 28

Na, Cl and K

Question 29

What substances are reabsorbed in the distal convoluted tubule?

Answer 29

Na, Cl, K, Ca, Mg and bicarbonate

Question 30

What substances are reabsorbed in the collecting duct?

Answer 30

Na, Cl, urea and water

Question 31

Where in the nephron are substances secreted?

Answer 31

Proximal convoluted tubule | Distal convoluted tubule

Question 32

What substances are secreted into the proximal convoluted tubule?

Answer 32

Creatinine, drugs and H+

Question 33

What substances are secreted into the distal convoluted tubule?

Answer 33

H+ and K+

Question 34

What pump is used to reabsorb glucose in the proximal convoluted tubule?

Answer 34

Na-glucose pump

Question 35

What pump is used to reabsorb sodium in the proximal convoluted tubule?

Answer 35

Na/K/ATPase pump

Question 36

What enzyme is responsible for acid-base balance in the proximal convoluted tubule?

Answer 36

Carbonic anhydrase

Question 37

Bicarbonate reabsorption in the proximal tubule is sodium-dependent/independent

Answer 37

Sodium dependent

Question 38

What co-transporter is expressed in the ascending limb of the loop of Henle?

Answer 38

K/Na/Cl triple co-transporter

Question 39

In the distal convoluted tubule, magnesium and calcium are reabsorbed trans/paracellularly

Answer 39

Paracellularly

Question 40

What hormone controls sodium reabsorption and potassium secretion in the distal tubule/collecting duct?

Answer 40

Aldosterone

Question 41

What channels allow for water reabsorption?

Answer 41

Aquaporins

Question 42

What is the effect of ADH on aquaporins?

Answer 42

Increased expression of aquaporins causing increased water reabsorption