Renal System 3 Flashcards Preview

Medsci142 Term 2 > Renal System 3 > Flashcards

Flashcards in Renal System 3 Deck (53)
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1

What is blood flow to the kidney like, and how does it affect glomerular filtration rate?

Blood flow is tightly regulated, so the glomerular filtration rate is relatively constant

2

What is urine output directly proportional to?

Renal pressure

3

What is special about the glomerular capillaries?

It has arterioles before and after it

4

What does arterioles on either side of the glomerular capillaries (glomerulus) allow for ?

Tight regulation of pressure gradients to maintain near constant glomerular filtration rates

5

What can control the glomerular filtration rate when there's an increase in arterial pressure?

It can be buffered by the vasoconstriction of afferent arterioles

6

How can glomerular filtration rate remain constant when there's a decrease in arterioles pressure?

It can be buffered by the vasoconstriction of efferent arteriole

7

What do you not want glomerular filtration to respond to?

Rapid blood pressure change

8

When does glomerulus pressure drop?

When there's constriction upstream (afferent)

9

When does glomerulus pressure increase?

When there's constricted efferent arterioles downstream

10

What is glomerular pressure equal to?

Exactly between the afferent and efferent arteriole pressures

11

What is afferent and efferent arteriole pressure if glomerular pressure is 55mmHg?

Afferent= 60
Efferent= 50

12

What is efferent/afferent pressure if glomerular pressure is 52.5

Afferent; 55
Efferent; 50

13

What is afferent/efferent pressure if glomerular pressure is 57.5?

Afferent; 60
Efferent; 55

14

What is glomerular filtration determined by?

Net filtration pressure

15

What does net filtration pressure equal?

Glomerular (blood) hydrostatic pressure - blood colloid osmotic pressure - capsular hydrostatic pressure

AKA 10mmHg

16

What is average glomerular (blood) hydrostatic pressure?

50mmHg

17

What is blood colloid osmotic pressure?

25mmHg

18

What does net filtration determine?

How much water and small dissolved dilutes leave the blood

19

What is glomerular blood hydrostatic pressure?

The mechanical pressure between the afferent and efferent arterioles (ie within the glomerulus; drives the plasma filtrate from the capillaries of the glomerulus into the capsules space)

20

What is capsular hydrostatic pressure?

The pressure exerted on the plasma filtrate by the elastic recoil of the glomerular capsule

21

What is blood colloid osmotic pressure?

The osmotic force which is of the proteins left in the plasma; the proteins exert an increasing osmotic "pull" on the water filter in the plasma filtrate

22

What is autoregulation of glomerular filtration?

Vasoconstriction

23

What is neural regulation of the glomerular filtration?

Increased sympathetic nerve activity leads to vasoconstriction

24

What is hormonal regulation of glomerular filtration?

Angiotensin 2 via vasoconstriction of afferent and efferent arterioles

Atrial naturetic peptide via relaxation of mesangial cells, increasing surface area available for filtration

25

What regulates the glomerular filtration?

Anything that alters the glomerular hydrostatic blood pressure (eg pressure of the afferent artery) and anything that alters the surface areas available for filtration

26

What are the two types of nephrons?

1. Cortical nephrons (dilute urine)
2. Juxamedullary nephron (important in production of concentrated urine)

27

What is the medulla like?

Has a high concentration of urea and salts

28

What occurs at the proximal convoluted tubule?

The largest amount of solute and water reabsorption from fluid

29

Percentages of solute and water reabsorption in proximal convoluted tubule?

60% glomerular filtrate
60% NaCl and water
100% glucose

30

What is the proximal convoluted tubule like?

Highly active in membrane transport process with reabsorption of water, ions and glucose