Concentration and Dilution of Urine Flashcards Preview

Block 2 Week 5 > Concentration and Dilution of Urine > Flashcards

Flashcards in Concentration and Dilution of Urine Deck (57)
Loading flashcards...
1

(blank) is a mechanism that expends energy to create a concentration gradient. Useful in creating hypertonic urine.

a countercurrent multiplier system

2

The countercurrent flow within the descending and ascending limb thus increases, or multiplies the (blank) between tubular fluid and interstitial space

osmotic gradient

3

Where can water leave?

descending limb

4

Where can salt leave?

ascending limb

5

normal urine osmolarity is (blank)

hypertonic

6

What is the normal process of creating hypertonic urine?

create isotonic, create hypotonic-> finish with hypertonic

7

(blank) and (blank) are critical for formation of a hypertonic urine.

ADH and interstitial osmotic gradint

8

The more your interstitial osmotic gradient the more (blank) your urine.

hypertonic

9

What allows for water to leave in the collecting duct?

ADH (w/ aquaporins) : )

10

An interstitial gradient is present from cortex to (blank) region throughout the kidney

papillary region
(osmotic gradient is lowest (300) at cortex and highest (1200) at papillary region)

11

What is the corticopapillary osmotic gradient primarily composed of?

NaCl and Urea

12

The corticopapillary osmotic gradient is established by (blank) and urea recycling and is maintained by (blank) in the vasa recta/

countercurrent multiplication
countercurrent exchange

13

What does counter current multiplication in the loop of henle depend on?

NaCl reabsorption in the thick ascending limb and countercurrent flow in the descending and ascending limbs of the loop of henle

14

Countercurrent multiplication is augemented by (blank) which stimulates NaCl reabsorption in thick ascending limb.

ADH

15

The presence of (blank) increases the size of the corticopapillary osmotic gradient.

ADH

16

(blank) from the inner medullary collecting ducts into the medullary interstitial fluid also is augmented by ADH

Urea recycling

17

Vasa Recta are the capillaries that supply the loop of henle. They maintain the corticopapillary gradient by serving as (blank).

OSMOTIC EXCHANGERS

18

(blank) equilibrates osmotically with the interstitial fluid of the medulla and papilla.

vasa recta

19

What are the phases and what is happening during counter current multiplication (i.e. active creation of interstitial gradient)?

start at equilibrium-> pump ions out of ascending limb of loop of henle (water remains stuck in loop)->increased interstitial fluid osmolarity so water leaves during descending limb->increased osmolality of filtrate entering the ascending limb

20

As water and solutes are reabsorbed, the loop first concentrates the filtrate and then (blank) it.

dilutes

21

Which nephrons create the gradient?

juxtamedullary

22

Do you get passive secretion of salt in the descending limb of the loop of henle?

yes PASSIVE not active

23

(blank) are specialized peritubular capillaries that remove excess salt and water from the medullary/papillary region.

vasa recta

24

Site of reabsorption, results in doubling of flow exiting from it.It provides oxygen and nutrients too!

vasa recta

25

What is the purpose of the vasa recta?

to prevent salt from being washed away

26

Is this true? Plasma flow exiting from the vasa recta is approximately twice that entering the vasa recta?

true!!

27

Is this true? Plasma flow exiting from the glomerular capillaires (toward peritubular capillaries) is app. 20% less than that entering the glomerular capillaries

True!

28

Is this true?
Approximately half of the renal blood flow goes to th renal cortex and half to the medullary/papillary region?

FALSE!!! 85% to cortex

29

Is this true?
The mean hydrostatic pressure of peritubular capillaries is less than that of glomerular capillaries?

True

30

Is this true?
The filtration coefficient (Kf) of glomerular capillaries is greater than for skeletal muscle capillaries?

True