Chapter 26: Urine Formation by the Kidneys I

Question 0

Constriction of renal arterioles caused by pain impulses when a ureter is blocked.

Answer 0

Ureterorenal reflex

Question 1

Characteristic of the micturition reflex

Answer 1

Self-regenerative

Question 2

Micturition contractions are the result of a stretch reflex initiated by what receptors in the bladder wall

Answer 2

Sensory stretch receptors

Question 3

Powerful micturition reflex passes through which nerve to inhibit the external sphincter

Answer 3

Pudendal nerve

Question 4

What metabolic products are excreted in this manner: excretion rate is equal to the rate at which it was filtered.

Answer 4

Waste products such as creatinine

Question 5

Rate of urinary excretion is less than the rate of filtration at the glomerular capillaries means that substances are partly reabsorbed and partly excreted. What are these substances?

Answer 5

Electrolytes such as Na and Cl

Question 6

What substances are freely filtered but not excreted into the urine?

Answer 6

Nutritional substances such as amino acids and glucose

Question 7

These substances are freely filtered but not reabsorbed and additional quantities are secreted from the peritubular capillaries.

Answer 7

Organic acids and bases

Question 8

Forces favoring filtration

Answer 8

Glomerular hydrostatic pressure - 60 mmHg

Bowman’s capsule colloid osmotic pressure - 0 mmHg

Question 9

Forces opposing filtration

Answer 9

Glomerular capillary colloid osmotic pressure - 32 mmHg

Bowman’s capsule hydrostatic pressure - 18 mmHg

Question 10

Measure of the product of the hydraulic conductivity and surface area of the glomerular capillaries

Answer 10

Filtration coefficient

Question 11

Increased Kf increases GFR. True or False.

Answer 11

True

Question 12

Obstruction in the urinary tract increases what pressure. Give its net effect to GFR.

Answer 12

Increases Bowman’s capsule hydrostatic pressure

Decreases GFR

Question 13

Fraction of plasma filtered by the glomerular capillaries

Answer 13

Filtration fraction

Question 14

Effect of decreased renal blood flow to filtration fraction and GFR

Answer 14

Increased filtration fraction –> concentrates plasma proteins –> increases glomerular colloid osmotic pressure –> decreases GFR

Question 15

Changes in which pressure serve as the primary means for physiologic regulation of GFR

Answer 15

Glomerular capillary hydrostatic pressure

Question 16

3 variables that determine glomerular capillary hydrostatic pressure

Answer 16

Arterial pressure
Afferent arteriolar resistance
Efferent arteriolar resistance

Question 17

Give the effects of the following to glomerular hydrostatic pressure and GFR:
A. Increased arterial pressure
B. Constricted afferent arteriole
C. Moderate Constricted efferent arteriole

Answer 17

A - inc
B - dec
C - inc

Question 18

Effect of SEVERE constriction of efferent arterioles to GFR

Answer 18

Dec renal blood flow –> inc filtration fraction –> inc glomerular colloid osmotic pressure –> dec GFR

Rise in colloid osmotic pressure exceeds glom cap hydrostatic pressure thus dec GFR

Question 19

Effect of vasoconstrictor hormones (norepinephrine and endothelin) to GFR

Answer 19

Constricts afferent arterioles –> dec glom cap hydrostatic pressure –> dec GFR

Question 20

Kidneys normally consume Oxygen at twice the rate of the brain but have almost seven times the blood flow of the brain. True / False

Answer 20

TRUE

Question 21

Effective mechanisms by the kidneys for maintaining renal blood flow and GFR relatively constant over an arterial pressure range between 80 and 179 mmHg

Answer 21

Autoregulation

Question 22

Two determinants of GFR that are most variable and subject to physiologic control

Answer 22

Glomerular hydrostatic pressure

Glomerular capillary colloid osmotic pressure

Question 23

Substances that protect the preglomerular blood vessels, especially the renal arterioles from angiotensin II-mediated constriction

Answer 23

NO and prostaglandins (counteracts the vasoconstrictor effects of angiotensin II)

Question 24

Angiotensin II acts on which blood vessel?

Answer 24

Efferent arteriole

Question 25

Adaptive mechanisms of the renal tubules that cause them to increase their reabsorption rate when GFR increases

Answer 25

Glomerulotubular balance

Question 26

2 effects of decrease NaCl concentration in the macula densa

Answer 26

Decreases resistance to blood flow in afferent arterioles

Renin release

Question 27

Important complication of using ACE inhibitors for the treatment of Hypertension caused by renal artery stenosis.

Answer 27

Severe decrease in GFR

Question 28

Ability of individual blood vessels to resist stretching during increased arterial pressure

Answer 28

Myogenic mechanism

Question 29

High protein intake and increases in blood glucose levels in uncontrolled DM increases renal blood flow and GFR. True or False

Answer 29

True

Question 30

Substances found in plasma which are not filtered in the glomerulus

Answer 30

Plasma proteins

Substances partially bound to plasma (Calcium and Fatty Acids)