Exam #3 - "Crunch Time" Cards

Question 1

The juxtaglomerular complex consists of the afferent/efferent juxtaglomerular cells and the _______.

A. macula densa
B. Bowman’s capsule
C. PCT

Answer 1

A. macula densa

Question 2

Explain the process by which the JG complex influences autoregulation.

Answer 2

1) Decreased GFR produces decreased NaCl in the macula densa; activation of the RAAS system occurs
2) Renin is released from the kidney’s JG cells
3) Renin catalyzes: angiotensinogen —> ANG I
4) ACE in lungs converts ANG I to ANG II
5) ANG II releases aldosterone from the renal cortex
6) Increased efferent arteriole resistance increases GFR

Question 3

Norepinephrine and epinephrine act to produce ______.

A. vasodilation
B. vasoconstriction

Answer 3

B. vasoconstriction

Question 4

Endothelin produces _____ after damage to blood vessels

A. vasoconstriction
B. vasodilation

Answer 4

B. vasoconstriction

Question 5

Angiotension II produces preferential constriction of _____ arterioles and ____ GFR.

Answer 5

efferent; increased (helps increased blood pressure)

Question 6

This maintains normal renal vasodilation

Answer 6

nitric oxide

Question 7

These work to offset the effects of sympathetic and angiotensin II induced vasoconstriction.

Answer 7

Prostaglandins/bradykinin

Question 8

The Loop of Henle is highly permeable to _______.

A. water
B. sodium
C. water and urea
D. None of the above

Answer 8

C. water and urea

Question 9

Principal cells are responsible for the (reabsorption/secretion) of K+ in the presence of aldosterone.

Answer 9

secretion

*Aldosterone acts here to stimulate the secretion of potassium.

(“PPS-principal-potassium-secretion”)

Basolateral Na/K ATPases pump K into the cell and Na into blood. The K then flows through K+ channels into the tubular lumen for secretion/excretion.

Question 10

Intercalated cells work to _____ potassium via a luminal H/K ATPase.

Answer 10

absorb

Question 11

Atrial natriuretic peptide secretion is stimulated by _____ stretching atrial cells.

Answer 11

increased venous return (blood volume)

Question 12

ANP causes what change to fluid dynamics in the kidney?

Answer 12

Increased sodium/H20 excretion

Question 13

A patient presents in the ED and is highly agitated. The pt’s medical history is significant for previous episodes of low aldosterone levels. What would one expect to see in the patient’s blood chemistry?

A. Elevated K+
B. Elevated Na+

Answer 13

A. Elevated K+/decreased Na+.

Aldosterone is responsible for the secretion of excess potassium. Low Aldosterone levels (“Addison’s Disease) will result in lowered ECF [Na] and increased ECF [K].

Remember that aldosterone is part of the RAAS, and is responsible for increasing sodium resorption when stimulated by low blood pressure/low [NaCl] at the macula densa.

Question 14

The principle of _____ assists in maintaining a relatively constant GFR. It is responsible for preventing large changes of glomerular filtration that would otherwise occur with large changes in blood pressure.

Answer 14

Autoregulation

Question 15

Normal ICF [K] is _______.

A. 140 mEq/L ( 0.3mEq/L)
B. 4.2 mEq/L ( 0.3mEq/L)
C. 150 mEq/L
D. 5 mEq/L

Answer 15

A. 140 mEq/L ( 0.3mEq/L)

Question 16

Which of the following will not cause an increase in [K]ECF?

A. Cell lysis
B. Alkalosis
C. Heavy exercise
D. Acidosis

Answer 16

B. Aklalosis

Question 17

Which of the following cells is acted upon by aldosterone?

A. Intercalated
B. PCT
C. Principle
D. DCT

Answer 17

C. Principle

Principle-Potassium-Secretion

• Aldosterone acts to increase the secretion of K+ at intercalated cells

Question 18

A primary change in ____ is responsible for metabolic alkalosis/acidosis.

A. CO2
B. HCO3

Answer 18

B. HCO3

Question 19

The major buffer of the ECF is the ____ system.

A. protein buffer
B. ammonia
C. phosphate
D. Bicarbonate

Answer 19

D. Bicarbonate

Question 20

What two systems are responsible for large amounts of H+ buffering?

Answer 20

Phosphate and ammonia buffers

Question 21

Respiratory acidosis is primarily caused by changes to ____.

A. CO2
B. HCO3

Answer 21

A. CO2

Question 22

Explain the process of generating a “new” bicarbonate ion.

Answer 22

Excess hydrogen is eliminated by phosphate or ammonia buffers.

In order to generate the hydrogen ions for excretion, CO2 and water must dissociate into H+ and HCO3. This HCO3 is then reabsorbed into the blood.

Question 23

What limits the PO2 in tissues to 149 mmHg?

Answer 23

The PO2 at sea level in atmospheric air is 150 mmHg. Therefore, alveolar PO2 cannot rise above this level.

Question 24

Describe the concept of “shunted blood”

Answer 24

A small amount of venous blood passing through the pulmonary capillaries is NOT oxygenated. Additionally, some blood goes through bronchial vessels, not alveolar capillaries. This blood does not participate in gas exchange.

Question 25

The respiratory unit terminates in the alveoli. However, the terminal bronchiole is called the _____.

A. alveolar duct
B. tertiary bronchiole
C. respiratory bronchiole

Answer 25

C. respiratory bronchiole

Question 26

Describe the respiratory membrane layers from vessel to alveolus.

Answer 26

Blood, endothelium, capillary BM, interstitial space, epithelial BM, alveolar epithelium, atmospheric gas