Overview and RBF

Question 1

What percentage of people 20 yrs or older have chronic kidney disease?

Answer 1

10%

Question 2

What percentage of nephrons are cortical vs. juxtamedullary?

Answer 2

85% vs 15%

Question 3

Which nephrons have long Loops of Henle?

Answer 3

Juxtamedullary

Question 4

The ascending loop of the kidney and the collecting duct are permeable/impermeable?

Answer 4

highly impermeable

Question 5

Resistance to RBF from glomerulus to collecting duct

Answer 5

glomerulus
proximal tubule
thin descending limb
thin ascending limb
thick ascending limb 
macula densa
distal tubule
collecting duct

Question 6

These determine the relative ability of water and particles to move via a paracellular route

Answer 6

tight junction proteins

Question 7

______ greatly increases water permeability in the collecting duct by recruiting water channels (aquaporins)

Answer 7

ADH

Question 8

Subset of peritubular capillaries supplying the JM nephrons

Answer 8

Vasa recta

Question 9

These cells lie next to the distal tubule and give feedback to the glomerulus and the affarent arteriole concerning the level of flow

Answer 9

macula densa cells

Question 10

A mechanism that serves to maintain a relatively constant GFR by sensing NaCl levels in the distal nephron and releasing substances that feed back onto the glomerulus to modify arteriolar resistance in both efferent and afferent vessels.

Answer 10

Tubuloglomerular feedback

Question 11

If the efferent arteriole contracts, what will happen to the filtration fraction?

Answer 11

It will increase

Question 12

If the efferent arteriole dilates, what will happen to the filtration fraction?

Answer 12

It will decrease

Question 13

What are the two components of the filtration fraction?

Answer 13

GFR (glomerular filtration rate) and renal plasma flow

Question 14

The intrinsic ability of the kidney to adjust vascular resistance to maintain blood flow at a relatively constant level when perfusion pressure changes.

Answer 14

Autoregulation

Question 15

Two mechanisms underlying autoregulation of RBF

Answer 15

1. myogenic response

2. tubuloglomerular feedback

Question 16

Autoregulation of blood flow to the kidneys relies primarily on

Answer 16

the afferent arteriole

Question 17

Other factors modifying RBF

Answer 17

1. nerves

2. hormones (RAAS)

Question 18

Factors regulating renin release

Answer 18

1. decreased stretch in afferent arteriole
2. decreased macula densa NaCl delivery
3. increased sympathetic nerve activity

Question 19

When renal blood flow increases, oxygen consumption _____________.

Answer 19

increases

Question 20

What determines the relative ability of water and particles to move between cells (paracellular).
Two examples of tight junction proteins.

Answer 20

Tight junction proteins

Claudins and occludins

Question 21

How does ADH greatly increase water permeability in the collecting duct?

Answer 21

It recruits aquaporins.

Question 22

What are two effects caused by decreased NaCl sensed by the macula densa?

Answer 22

1. decrease afferent arteriolar resistance to increase flow

2. increase efferent arteriolar resistance to increase flow

Question 23

Main action in myogenic response to increased perfusion pressure

Answer 23

Increase resistance at afferent arteriole

Question 24

Does water reabsorption occur at the glomerulus?

Answer 24

No!

Question 25

Is water absorption paracellular in the proximal tubule?

Answer 25

Yes

Question 26

Is water reabsorption paracellular in the collecting duct?

Answer 26

No

Question 27

Compare the starling forces in the glomerular capillaries to the forces in the skeletal muscle capillaries.

Answer 27

In glomerular capillaries, the hydrostatic pressure of the capillary is higher.
The osmotic pressure of the capillary rises to a greater degree.
Efferent arterioles provide greater resistance than the venules in skeletal muscle.

Question 28

4 things that increase K+ secretion

Answer 28

1. aldosterone
2. hyperkalemia
3. furosemide
4. thiazide diuretics