Lecture 16 - Tubular Reabsorption and Secretion Flashcards
Sodium channels found in apical membrane of all nephron cells
ENaC channel (epithelial Na Channel)
Chrloride and K+ channels are found in the ____ membranes of all nephron cells.
A. Apical
B. Basolateral
C. Basal
D. Lateral
A. apical (facing the lumen)
Contain numerous mitochondria and have extensive brush borders. A. PCT B. DCT C. Loop of Henle D. Collecting Tubule
A. PCT
The cells of the PCT resorb ____ of Na, Cl, H2CO3, and K.
65%
The cells of the PCT resorb ____ of glucose and amino acids.
100%
The PCT cells are responsible for the (secretion/resorption) of acids, bases, and H+ ions.
secretion
The PCT cells resorb Na along with \_\_\_\_\_\_ through co-transport. A. Cl- B. Organic Acids, organic bases C. glucose, AAs D. K+, H2CO3
C. glucose, AAs
The second half of the PCT resorbs Na via \_\_\_\_\_\_. A. Anti-transport of K+ B. Co-transport of K+ C. Anti-transport of Cl- D. Co-transport of Cl-
D. Co-transport of Cl-
The PCT works with anti-port transporters to secrete \_\_\_\_\_\_\_\_ into the tubular lumen. A. Cl- B. HCO3 C. H+ D. K+
C. H+
The thin descending segment of the Loop of Henle is highly permeable to ________.
A. Urea
B. Sodium
C. Water
D. Cl
C. Water
The thin descending segment of the Loop of Henle is moderately permeable to ________.
A. Urea B. Sodium C. Water D. Cl E. A & D F. A & B
F. A & B
The thick ascending limb of the loop of Henle is responsible for the secretion of _____________.
A. H+
B. Mg 2+
C. Na+
D. K+
A. H+
The thick ascending mechanism establishes a NaCl gradient through apical ______.
a. ENaC
B. Na/K pumps
C. Na/2Cl/K channel
D. K+ channels
C. Na/2Cl/K channel
The ascending limb of the Loop of Henle utilizes what mechanism for chloride resorption?
1) Na/2Cl/K pump into tubular epithelial cell
2) K+ diffuses through channel into the interstitial fluid
Na/KATPase is located on the ____ side of the ascending limb of the Loop of Henle.
a. apical
b. basolateral
b. basolateral
The +8mV charge of the tubular fluid is produced primarily by _________.
a. diffusion of H+ into the tubular lumen
b. Na/H co-transport of H+ into the tubular lumen
C. Na/K ATPase moving K+ into the tubular lumen
D. Diffusion of K+ into the tubular lumen
D. diffusion of K+ into the lumen
Why is the basolateral Na/KATPase important in the thick ascending loop?
The basolateral Na/KATPase acts to pump Na into the renal interstitium (against the Na gradient). This allows the diffusion of Na from the renal tubule. This Na movement is accomplished through a Na/H counter-transport, permitting H+ secretion and eventual excretion.
The thin ascending segment of the Loop of Henle is (permeable/impermeable) to water.
impermeable (allows for concentration of urine and establishment of the counter-current multiplication system)
Widespread aquaporin, including within the renal tubules.
A. Aquaporin-1
B. Aquaporin-2
C. Aquaporin-3
A. Aquaporin-1
Aquaporin within the basolateral membrane of the collecting tubules.
A. Aquaporin-1
B. Aquaporin-2
C. Aquaporin-3
C. Aquaporin-3
Aquaporin located in the apical membrane of the collecting tubule. Is sensitive to ADH.
A. Aquaporin-1
B. Aquaporin-2
C. Aquaporin-3
B. Aquaporin-2
Primary active transporters utilize ____ directly to move a solute ____ a concentration gradient.
ATP; against
The PCT utilizes secondary active transport to reabsorb ________.
A. amino acids and glucose
B. organic acids and glucose
C. sodium and amino acids
D. water and glucose
A. amino acids and glucose
What solutes are actively secreted into the renal tubules?
creatine and para-aminohippuric acid
Two factors affect the rate of transport of substances out of the tubule. What are they?
electrochemical gradient and time in the tubule
A high electrochemical gradient increases the likelihood of diffusion.
A rapid renal tubule flow will decrease the time that the solute spends in a given area of the tubule.
“Time-gradient diffusion”
The source of aldosterone is:
A. Adrenal cortex
B. Anterior pituitary
C. Posterior pituitary
D. Hypothalamus
A. Adrenal cortex
The source of ADH is:
A. Adrenal cortex
B. Anterior pituitary
C. Posterior pituitary
D. Hypothalamus
C. Posterior pituitary
This hormone is released by increased [K] and [ANG II]. It’s function is to resorb sodium and excrete potassium.
A. ADH
B. ANG I
C. ANG II
D. Aldosterone
D. Aldosterone
This hormone increases water and sodium resorbtion. It functions to release aldosterone and constrict efferent arterioles.
A. ADH
B. ANG I
C. ANG II
D. Aldosterone
C. ANG II
Binding of this hormone to the V2-R on the DCT promotes increased water reabsorption. What is the hormone and what is its mechanism of action?
A. AGN II; increased Aquaporin-2 in the DCT membrane
B. ADH; Increased aquaporin-2 in the DCT membrane
C. Renin; increased diffusion of water across the renal plasma membrane
D. AGN II: increased diffusion of water across the renal plasma membrane
B. ADH; Increased aquaporin-2 in the DCT membrane
