Section 3 Quiz 2

Question 1

two types of cells in collecting tubule

Answer 1

1. principal: maintains Na+/K+ ion balance
2. intercalated: acid-base regulation

Question 2

what hormones controls the permeability to water

Answer 2

ADH

Question 3

final site for processing urine

Answer 3

the medullary collecting duct

Question 4

high ADH levels

Answer 4

high water reabsorption = reduction of urine volume

Question 5

most important segment for reabsorption and secretion

Answer 5

proximal tubule

Question 6

descending LOH

Answer 6

mainly water reabsorption

Question 7

thick ascending LOH and distal tubule

Answer 7

ion reapsorption, impermeable to water

Question 8

how are metabolic wastes (creatine and urea) removed?

Answer 8

from blood via the glomerular filtration and then excreted in the urine by failing to be entrely reabsorbed.

Question 9

high GFR leads to

Answer 9

high filtrate volume -> lower blood volume and BP

Question 10

filtration efficacy

Answer 10

kidneys need a relative constant GFR to maintain filtration ability

Question 11

blood presssure

Answer 11

removing fluid from blood modulates blood volume which changes BP

Question 12

intrinsic control

Answer 12

renal autoregulation -local control in the kidney. maintains GFR

Question 13

extrinsic control

Answer 13

control by the nervous system and endocrine system. maintains BP by regulating GFR

Question 14

renal autoregulation

Answer 14

kidney adjusts its own resistance to blood flow to modulate GFR

Question 15

myogenic mechanism:

Answer 15

tendancy of vascular smooth muscle to contract when stretched. Increase BP = constriction of afferent arterioles = increase Ra = decrease Pg = decrease GFR

Question 16

tubuloglomerular mechanism:

Answer 16

-directed by macula densa (part of juxtaglomerular apparatus)
-chemoreceptors detects the NaCl in the filtrate in the distal tubule
-high NaCl causes the macula densa to release vasoconstrictor. on afferent arterioles which increases Ra, decreses Pg, and decreases GFR.
-end result: decrease GFR

Question 17

sympahetic nervous system:

Answer 17

causes constriction of renal arteries which decreases renal blood flow, and descreases GFR

Question 18

hormonal controls:

Answer 18

-nonepinephrine/epinephrine: systemic vasoconstriction, increase BP, increase Ra, decrease GFR, increase blood volume by decreasing urine output
-endothelin: peptide released by damaged vascular endothelium. vasoconstricts afferent/efferent arterioles to decrease rneal blood flow
-angiotensin II: a hormone that vasocontricts efferent arterioles. increases Re, decreases renal blood flow, decreases flow through peritubular capilaries, increases reabsportion, prevents decrease to blood volume.

Question 19

renin angiotensin mechanism

Answer 19

regulates BP directed by kidneys

Question 20

renin

Answer 20

hormone released by jutaglomerular cells due to low BP or low GFR. catalyzes conversion of angiotensin to angiotensin II.
-direct: low BP, reduce stretch in arterioles, activates juxtaglomerular cells directly
-indirect: signaling from macula densa cells to juxtaglomerular cells via chemical messengers

Question 21

angiotenesin II

Answer 21

-vasoconstrictor thorughout the body which raises mean arterial pressure.
-preferential vasocontriction of efferent arterioles = increase in Re
-decreased renal blood flow, decrease blood flow throughout pertitubular capillaries, increases reabsorption of Na+ and water in tubules, restores blood volume
-prevents further decrease in Pg and GFR and allows kidneys to continue filtering out wastes in times of low BP
-stimuluares reabsorption of Na+ in the tubules, water flollows Na+. blood volume and BP increase

Question 21

renin-angiotensin mechanism

Answer 21

-stimulates juxtaglomerular cells to release. renin
-renin catlyzes angiotensin to angiotensin II
-angiotensin II increases Re, increases Pg, and increases GFR

Question 22

macula densa

Answer 22

detects low NaCl and has renin-angiotensin mechanism and tubuloglomerular feedback

Question 23

tubuloglomerular feedback

Answer 23

-inhibits vasoconctrictors to release
-decrease Ra, increase Pg and GFR