Urinary Physiology

Question 1

What makes up a renal corpuscle?

Answer 1

Glomerulus and Bowman’s capsule

Question 2

What are the 3 layers of the glomerulus?

Answer 2

Fenestrated capillaries
Glomerular basement membrane
Podocytes

Question 3

What connects podocytes?

Answer 3

Nephrin proteins

Question 4

What lies between podocytes?

Answer 4

Slit pores

Question 5

What are mesangial cells?

Answer 5

Phagocyte macromolecules that make it through the basement membrane

Question 6

What is GFR?

Answer 6

How much blood the kidney filters each miniute

Question 7

What is normal GFR?

Answer 7

125ml/min

Question 8

What happens to GFR in increased afferent arteriole resistance?

Answer 8

Decreased GFR

Question 9

What happens to GFR in increased efferent arteriole resistance?

Answer 9

Increased GFR

Question 10

What starling force favours filtration?

Answer 10

Hydrostatic pressure

Question 11

What starling force favours reabsorption?

Answer 11

Oncotic pressure

Question 12

Which starling force dominates in the glomerular capillaries?

Answer 12

Hydrostatic pressure

Question 13

Which starling force dominates in the peritubular capillaries?

Answer 13

Oncotic pressure

Question 14

What is reabsorbed at the proximal tubule?

Answer 14

Sodium
Glucose
Water
Chloride
Old HCO3-

Question 15

What is the process of Na+ reabsorption?

Answer 15

Na+- K+ ATPase creates the conc. gradient
This drives the SGLT symporter
This also drives the Na+-H+ antiporter

Question 16

What is the process of old HCO3- reabsorption?

Answer 16

Na+- H+ antiporter uses H+ from carbonic acid and the HCO3- leaves via Na+- HCO3- symporter

Question 17

What is reabsorbed at the descending limb of the loop of henle?

Answer 17

Water via aquaporin channels

Question 18

What is reabsorbed at the ascending limb of the loop of henle?

Answer 18

Na+ and Cl- via NKCL2 transporter
No aquaporin channels

Question 19

What is the counter current multiplier?

Answer 19

Active transport of sodium in the ascending limb sets up the gradient for movement of water out of the descending limb
This creates a hypotonic solution in the DCT and a hyperosmotic environment in the interstitial medulla

Question 20

What ions are absorbed in the early DCT?

Answer 20

Na+
Cl-
Ca2+
Mg2+

Question 21

Is water absorbed in the DCT?

Answer 21

No it is impermeable to water like the ascending limb

Question 22

What are the 2 types of cells in the distal DCT?

Answer 22

Principal cells
Intercalated cells

Question 23

What is the function of principal cells?

Answer 23

Uptake of Na+
Secretion of K+

Question 24

What is the function of intercalated cells?

Answer 24

Acid base control- reabsorption of new HCO3-
- Phosphate buffers
- Ammonia buffers

Question 25

What is the process of new HCO3- reabsorption?

Answer 25

H+ pump- active transport of H+ into the tubule lumen

Question 26

What is another name for ADH?

Answer 26

Vasopressin

Question 27

Where is ADH secreted from?

Answer 27

Posterior pituitary

Question 28

What is the action of ADH?

Answer 28

Increases water reabsorption

Question 29

Where does AHD act in the nephron?

Answer 29

DIstal tubule and collecting ducts

Question 30

What is the impact of increased plasma volume on ADH release?

Answer 30

Increased volume (hypervolaemia) means decrease osmolality Osmoreceptors expand Decreased ADH release

Question 31

What is the impact of decreased plasma volume on ADH release?

Answer 31

Decreased volume (hypovolaemia) means increased osmolarity Osmoreceptors contract Increased ADH release

Question 32

What is the mechanism of ADH release?

Answer 32

Increased insertion of aquaporin channels in the apical membrane

Question 33

What is the end product of RAAS?

Answer 33

Angiotensin II

Question 34

What is the impact of angiotensin II on the arterioles?

Answer 34

Vasoconstriction

Question 35

What is the impact of angiotensin II on the kidney?

Answer 35

Increased Na+ reabsorption H2O retention

Question 36

What is the impact of angiotensin II on the sympathetic nervous system?

Answer 36

Increased NA release - Vasoconstriction - Renin release

Question 37

What is the impact of angiotensin II on the adrenal cortex?

Answer 37

Aldosterone release - Acts on principal cells of collecting ducts - Increases Na+ reabsorption and K+ excretion

Question 38

What 2 organs are involved in acid base balance?

Answer 38

Lungs- control CO2 Kidneys- control HCO3-

Question 39

How long does respiratory response take?

Answer 39

Minutes

Question 40

What is the function of the resp. system in acid base balance?

Answer 40

Chemoreceptors detect the high levels of H+ and CO2 in the blood and alter resp. rate accordingly

Question 41

Where are the resp. chemoreceptors?

Answer 41

Carotid body Aortic arch

Question 42

What is respiratory acidosis?

Answer 42

Low pH High pCO2 Compensation: increase HCO3-

Question 43

What causes resp. acidosis?

Answer 43

Opiates Sleep apnoea Lung disease

Question 44

What is respiratory alkalosis?

Answer 44

High pH Low pCO2 Compensation: decrease HCO3-

Question 45

What causes resp. alkalosis?

Answer 45

Hyperventilation Altitudes Aspirin

Question 46

How long does urinary response take?

Answer 46

Hours

Question 47

What is the function of the urinary system in acid base balance

Answer 47

Reabsorption of old HCO3- in the PCT Production of new HCO3- in the DCT Excretion of H+ ions as H2PO4- (phosphate buffer) or NH4+ (ammonia buffer)

Question 48

What is metabolic acidosis?

Answer 48

Low pH Low HCO3- Compensation: decrease PCO2

Question 49

What causes metabolic acidosis?

Answer 49

DKA Lactic acidosis Diarrhoea

Question 50

What is metabolic alkalosis?

Answer 50

High pH High HCO3- Compensation: increase PCO2

Question 51

What causes metabolic alkalosis?

Answer 51

Vomiting Diuretics Burns

Question 52

What is involved in micturition?

Answer 52

1. Stretch receptors in bladder wall fire 2. Parasympathetic neurons fire, sympathetic neurones stop firing 3. Inhibition of somatic motor neurones to external sphincter