Renal Physiology

Question 1

Kidneys can filter entire blood supply every ___ minutes, as well as filtrate at a rate of ____ L/min.

Answer 1

every 30 minutes; 1.1 L/min max rate

Question 2

Kidneys utilize ___-___% of our cardiac output

Answer 2

20-25%

Question 3

What functions are the kidneys responsible for in our bodies? (4)

Answer 3

1. Maintaining homeostasis of fluid, electrolytes, pH
2. Blood pressure
3. Erythropoiesis by synthesizing EPO
4. Synthesize active vitamin D

Question 4

Blood enters the kidney through the _____ _____.

Answer 4

Renal artery

Question 5

Blood travels to individual nephrons via the _____ ____.

Answer 5

Afferent arteriole

Question 6

Filtered blood is collected by the _____ _____ and exits through the efferent arteriole

Answer 6

Glomerular capillaries

Question 7

Urine is collected and removed through the _____.

Answer 7

Ureter

Question 8

How many nephrons are in each kidney?

Answer 8

1 million

Question 9

Unit of nephron responsible for filtration

Answer 9

Glomerulus

Question 10

Unit of nephron that collects filtrate

Answer 10

Bowman’s capsule

Question 11

Unit of nephron responsible for most (60%) of the reabsorption back into the blood stream of particles such as Na+, H20 and glucose

Answer 11

Proximal convoluted tubule

Question 12

Unit of nephron that is responsible for reabsorption via counter-current multiplication using H2O

Answer 12

Loop of Henle

Question 13

Which particles passively diffuse? (6)

Answer 13

1. Na+
2. K+
3. Cl-
4. H2O
5. Glucose
6. Urea

Question 14

Part of the Loop of Henle that is responsible for counter-current reabsorption of H2O.

Answer 14

Descending limb

Question 15

Part of Loop of Henle that is responsible for active reabsorption of Na+, Cl-, and K+ (ions)

Answer 15

Ascending limb

Question 16

Meaning putting back into bloodstream

Answer 16

Reabsorption

Question 17

Meaning tissues put material back into kidney

Answer 17

Secretion

Question 18

Describe briefly how the counter-current reabsorption works.

Answer 18

Ions are actively moved out of the ascending loop of Henle, which creates a gradient for water to passively follow out of the descending loop of henle and back into blood stream.

Question 19

Part of the distal convoluted tubule which monitors blood pressure and can alter fluid and ion retention

Answer 19

Juxtaglomerular apparatus

Question 20

Part of the nephron that reabsorbs H2O and urea

Answer 20

Collecting duct

Question 21

If the afferent artery diameter increases, the GFR

Answer 21

Increases

Question 22

If the efferent artery diameter increases, the GFR

Answer 22

Decreases

Question 23

If the afferent artery diameter decreases, the GFR

Answer 23

Decreases

Question 24

If the efferent artery diameter decreases, the GFR

Answer 24

Increases

Question 25

What does the RAAS system respond to?

Answer 25

Drop in blood pressure or change in blood sodium levels

Question 26

Which enzyme does the kidney release in response to decreased BP or SV?

Answer 26

Renin

Question 27

What effect does renin have?

Answer 27

Renin converts angiotensinogen to angiotensin I

Question 28

What happens to angiotensin I?

Answer 28

Angiotensin I is converted to angiotensin II by ACE

Question 29

What effect does angiotensin II have on the cardiovascular system?

Answer 29

Causes vasoconstriction, which increases vascular resistance and leads to increased blood pressure

Question 30

What effect does angiotensin II have on the kidneys?

Answer 30

Causes them to release aldosterone which increases salt and H2O retention and leads to increased blood pressure

Question 31

Formula for MAP

Answer 31

MAP = SV x HR x Resistance

Question 32

What does the kidney modify in the MAP equation?

Answer 32

SV and Resistance