Renal Physiology

Question 1

What is Wilm’s tumor?

Answer 1

A tumor of the kidney found in childhoood that is associated with aniridia and related ocular complications

Question 2

How many Wilm’s tumor cases occur in the US annually?

Answer 2

500

Question 3

How do the kidneys regulate osmotic pressure?

Answer 3

Excreting dilute or concentrated urine

Question 4

The kidneys regulate what molecules?

Answer 4

Na, K, Ca, Mg, Cl, HCO3, PO4, and SO4

Question 5

What do the kidneys eliminate from the system?

Answer 5

waste products - urea, uric acid, creatinine

Drugs and toxins

Question 6

The kidneys produce ______ and vitamin _

Answer 6

Erythropoietin and Vitamin D3

Question 7

The kidneys degrade ____ and ___

Answer 7

insulin and PTH

Question 8

The kidneys help regulate the acid/base balance by synthesizing _______

Answer 8

ammonia

Question 9

How do the kidneys regulate extracellular fluid?

Answer 9

By controlling Na and water excretion

Question 10

The kidneys adjust blood pressure by regulating __ excretion and producing ____

Answer 10

regulating Na excretion

producing renin

Question 11

The kidneys synthesize ____ and _____ which affect renal blood flow and Na excretion

Answer 11

Prostaglandins and kallikreins

Question 12

Total body water makes up __% of body weight

Answer 12

60%

Question 13

In regards to body fluid, the intracellular compartment makes up __% of body weight while the extracellular compartment make up __%

Answer 13

intracellular - 40%

extracellular - 20%

Question 14

What are the major electrolyte cations?

Answer 14

Na, K, Ca, Mg

Question 15

What are the major electrolye anions?

Answer 15

Cl, HCO3, PO4, SO4

Question 16

What does the macula densa of distal convoluted tubule do?

Answer 16

monitors composition of fluid in the tubular lumen

Question 17

What do the extraglomerular mesangial cells do?

Answer 17

Transmit information from macula densa to granular cells

Question 18

What is another name for the extraglomerular mesangial clles?

Answer 18

Lacis cells

Question 19

What do the granular cells do?

Answer 19

Synthesize renin

Question 20

What are granular cells made of? Where are they located?

Answer 20

Modified smooth muscle cells with epithelioid appearance located in afferent arteriole close to glomerulus

Question 21

The JG (granular) cells secrete renin in response to what?

Answer 21

1. Beta-1 adrenergic stimulation
2. Reduced renal perfusion pressure
3. Decreased NaCl reabsorption by the macula densa

Question 22

Reduced renal perfusion pressure is detected directly by _____

Answer 22

JG cells

Question 23

NaCl reabsorption by the macula densa is due to _____

Answer 23

reduction in glomerular filtration rate (GFR)

Question 24

Excreted = ____ - ____ + ____

Answer 24

Excreted = filtered - reabsorbed + secreted

Question 25

The clearance of substrate is equal to what?

Answer 25

[(Urine concentration of substance) x (urine flow rate)] / (plasma concentration of substance)

Question 26

What is the glomerular filtration rate (GFR)?

Answer 26

Rate at which plasma is filtered by the glomeruli

Question 27

Inulin clearance is the same thing as what?

Answer 27

the Glomerular filtration rate

Question 28

What are the normal values of the Glomerular filtration rate?

Answer 28

110 - 125 mL/min

Question 29

What fructose polymer is used to measure GFR?

Answer 29

inulin

Question 30

Why is inulin ideal to measure GFR?

Answer 30

1. Freely filterable by glomeruli 2. Not reabsorbed or secreted by tubules 3. Not synthesized, destroyed, or stored in kidneys 4. Nontoxic 5. Concentration in plasma and urine determined by simple analysis

Question 31

A clearance ratio of >1 indicates what?

Answer 31

Secretion

Question 32

A clearance ration of <1 indicates what?

Answer 32

Reabsorption

Question 33

Creatinine is a derivative of what substance?

Answer 33

creatine phosphate

Question 34

Why is the relationship between GFR and plasma creatinine inversely related?

Answer 34

the kidneys continuously clear creatinine from the plasma

Question 35

Creatinine adds __% to urinary values

Answer 35

20%

Question 36

What is the glucose threshold in urine?

Answer 36

200 mg%

Question 37

What two mechanisms do the kidneys use to autoregulate renal blood flow?

Answer 37

Myogenic mechanism | Tubuloglomerular feedback mechanism

Question 38

Is there more renal blood flow in the cortex or the medulla?

Answer 38

cortex

Question 39

How many liters per minute flow through the renal system?

Answer 39

1.2L / min

Question 40

What are the five major vasoconstrictors related to renal blood flow?

Answer 40

``` Adenosine Angiotensin II Endothelin Thromboxane Vasopressin ```

Question 41

What are the six major vasodilators related to renal blood flow?

Answer 41

``` Atrial natriuretic factor Dopamine Histamine Kinins NO Prostaglandins ```

Question 42

How does the Myogenic mechanism help autoregulate blood flow?

Answer 42

Increased pressure stretches vessels and opens cationic channels resulting in depolarization and calcium influx

Question 43

How does the tubuloglomerular feedback mechanism help autoregulate blood flow?

Answer 43

Increased pressure increases GFR -> increases NaCl reabsorption and ATP release from macula densa.

Question 44

What do the negative ions in the barrier of the Glomerulus do?

Answer 44

Restrict the filtration of negatively charged compounds such as albumin

Question 45

What is the driving force for reabsorption of solutes and water in the proximal convoluted tubule?

Answer 45

Na reabsorption by Na / K ATPase