Physiology 6

Question 1

tubular fluid entering the distal tubule is __osmotic to plasma

Answer 1

hypo

Question 2

osmolarity of the plasma?

Answer 2

300mosmol/l

Question 3

what does the distal tubule empty into?

Answer 3

collecting duct

Question 4

what hormone controls water reabsorption and what effect does it have on this?

Answer 4

ADH

increases rebasorption

Question 5

what hormone controls Na reabsorption? what effect does it have on this?

Answer 5

aldosterone

increases it

Question 6

aldosterone is responsible for secretion of which 2 ions?

Answer 6

H+

K+

Question 7

what hormone decreases Na reabsorption?

Answer 7

atrial natriuretic hormone

Question 8

PTH is responsible for the increased reabsorption of __ and the decreased reabsorption of __

Answer 8

calcium ions

PO4

Question 9

the distal tubule has __ permeability to water and urea

Answer 9

low

Question 10

where is urea concentrated?

Answer 10

tubular fluid

Question 11

what part of the distal tubule is responsible for NaCl absorption?

Answer 11

early part

Question 12

the late collecting duct is permeable to ions T or F

Answer 12

F, has a low ion permeability

Question 13

plasma half life of ADH?

Answer 13

10-15 mins

Question 14

how does ADH make the apical membrane more permeable to water?

Answer 14

inserts aquaporins into the membrane

Question 15

why do you get hypertonic urine when ADH is high?

Answer 15

causes more reabsorption of water via aquaporins -> more concentrated urine

Question 16

why is water not reabsorbed when there is no ADH?

Answer 16

no aquaporin channels can be created without ADH, so the collecting duct is impermeable

Question 17

does ADH have an effect on urine volume?

Answer 17

yes, it decreases it

Question 18

what controls thirst and ADH secretion?

Answer 18

hypothalamus

Question 19

what effect does ADH have on the blood vessels?

Answer 19

vasoconstricts them

Question 20

name the 2 kinds of diabetes insipidus

Answer 20

central

nephrogenic

Question 21

symptoms of diabetes insipidus?

Answer 21

large volumes of dilute urine

constant thirst

Question 22

Tx of diabetes insipidus?

Answer 22

ADH replacement

Question 23

decreased atrial pressure -> __ ADH release

Answer 23

increased

Question 24

nicotine stimulates ADH release T or F

Answer 24

T

Question 25

alcohol stimulates ADH release T or F

Answer 25

F (need to pee all the time when drunk)

Question 26

where in the nephron is the tubular fluid at its highest osmolarity?

Answer 26

descending loop of henle

Question 27

how does aldosterone increase BP?

Answer 27

it causes Na retention which causes high BP and blood volume

Question 28

where is most K+ normally reabsorbed?

Answer 28

proximal tubule

Question 29

what component of RAAS is responsible for inducing thirst?

Answer 29

angiotensin II

Question 30

where is renin released?

Answer 30

granular cells in the juxtaglomerular apparatus

Question 31

what effect does renin have on the body?

Answer 31

increases salt reabsorption increases blood pressure increases ECF/blood volume

Question 32

how does RAAS know if salt levels are low?

Answer 32

via macula densa cells (salt sensors)

Question 33

granular cells are directly innervated by what nerves?

Answer 33

sympathetics

Question 34

why do those with congestive heart failure retain fluid?

Answer 34

RAAS keeps working because it is responding to the low CO + BP patients with CCF get

Question 35

where is ANP stored?

Answer 35

atrial muscle cells

Question 36

when is ANP released?

Answer 36

when the atrial muscle cells become stretched by an increased circulating volume

Question 37

what does ANP do?

Answer 37

decreases Na reabsorption stops RAAS vasodilates SM of afferent arterioles decreases sympathetic nervous system

Question 38

why does ANP work on the sympathetic nervous system?

Answer 38

sympathetics increases CO and TPR and therefore BP

Question 39

name the 2 mechanisms that govern the process of urination

Answer 39

micturation reflex | voluntary control

Question 40

what volume can the bladder hold before the micturation reflex is initiated?

Answer 40

250-400ml

Question 41

what nerves control contraction of the bladder?

Answer 41

parasympathetics

Question 42

what controls voluntary control of micturation?

Answer 42

the cerebral cortex and motor nerves

Question 43

what does osmotic diuresis mean?

Answer 43

water loss

Question 44

what type of diuresis involves increased excretion of urine and solute?

Answer 44

osmotic diuresis