Exam #3 - "Crunch Time" Cards Flashcards
The juxtaglomerular complex consists of the afferent/efferent juxtaglomerular cells and the _______.
A. macula densa
B. Bowman’s capsule
C. PCT
A. macula densa
Explain the process by which the JG complex influences autoregulation.
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
Norepinephrine and epinephrine act to produce ______.
A. vasodilation
B. vasoconstriction
B. vasoconstriction
Endothelin produces _____ after damage to blood vessels
A. vasoconstriction
B. vasodilation
B. vasoconstriction
Angiotension II produces preferential constriction of _____ arterioles and ____ GFR.
efferent; increased (helps increased blood pressure)
This maintains normal renal vasodilation
nitric oxide
These work to offset the effects of sympathetic and angiotensin II induced vasoconstriction.
Prostaglandins/bradykinin
The Loop of Henle is highly permeable to _______.
A. water
B. sodium
C. water and urea
D. None of the above
C. water and urea
Principal cells are responsible for the (reabsorption/secretion) of K+ in the presence of aldosterone.
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.
Intercalated cells work to _____ potassium via a luminal H/K ATPase.
absorb
Atrial natriuretic peptide secretion is stimulated by _____ stretching atrial cells.
increased venous return (blood volume)
ANP causes what change to fluid dynamics in the kidney?
Increased sodium/H20 excretion
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+
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.
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.
Autoregulation
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
A. 140 mEq/L ( 0.3mEq/L)
Which of the following will not cause an increase in [K]ECF?
A. Cell lysis
B. Alkalosis
C. Heavy exercise
D. Acidosis
B. Aklalosis
Which of the following cells is acted upon by aldosterone?
A. Intercalated
B. PCT
C. Principle
D. DCT
C. Principle
Principle-Potassium-Secretion
- Aldosterone acts to increase the secretion of K+ at intercalated cells
A primary change in ____ is responsible for metabolic alkalosis/acidosis.
A. CO2
B. HCO3
B. HCO3
The major buffer of the ECF is the ____ system.
A. protein buffer
B. ammonia
C. phosphate
D. Bicarbonate
D. Bicarbonate
What two systems are responsible for large amounts of H+ buffering?
Phosphate and ammonia buffers
Respiratory acidosis is primarily caused by changes to ____.
A. CO2
B. HCO3
A. CO2
Explain the process of generating a “new” bicarbonate ion.
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.
What limits the PO2 in tissues to 149 mmHg?
The PO2 at sea level in atmospheric air is 150 mmHg. Therefore, alveolar PO2 cannot rise above this level.
Describe the concept of “shunted blood”
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.
The respiratory unit terminates in the alveoli. However, the terminal bronchiole is called the _____.
A. alveolar duct
B. tertiary bronchiole
C. respiratory bronchiole
C. respiratory bronchiole
Describe the respiratory membrane layers from vessel to alveolus.
Blood, endothelium, capillary BM, interstitial space, epithelial BM, alveolar epithelium, atmospheric gas
