Physiology - Endocrine Control

Question 1

what does the distal tubule empty into?

Answer 1

the collecting duct

Question 2

what are the major sites in the kidney for regulation of ion and water balance?

Answer 2

distal tubule

collecting duct

Question 3

what is another name for ADH?

Answer 3

vasopressin

Question 4

what effect does ADH have on water?

Answer 4

increases water reabsorption

Question 5

what effect does aldosterone have on ions?

Answer 5

increases sodium reabsorption

increases H+ and K+ secretion

Question 6

what effect does ANH have on ions?

Answer 6

reduces sodium reabsorption

Question 7

what is ANH?

Answer 7

anti natriuretic hormone

Question 8

what effect does PTH have on ions?

Answer 8

increased calcium reabsorption

decreases phosphorus reabsorption

Question 9

what is the permeability like to water and urea in the distal tubule?

Answer 9

low

can be increased by ADH

Question 10

what are the two segments of the distal tubule?

Answer 10

early

late

Question 11

what happens in the early distal tubule?

Answer 11

NaCl reabsorption

Question 12

what happens in the late distal tubule?

Answer 12

calcium reabsorption
H secretion
sodium reabsorption
potassium reabsorption

Question 13

what do levels of sodium and potassium reabsorption in the distal tubule depend on?

Answer 13

aldosterone levels

Question 14

what does aldosterone promote in the late distal tubule?

Answer 14

potassium secretion

Question 15

where is ADH released from?

Answer 15

posterior pituitary

Question 16

when is ADH released from the posterior pituitary?

Answer 16

when AP’s down the nerves lead to calcium ion dependent exocytosis

Question 17

what is the primary stimulus for ADH release?

Answer 17

dehydration

Question 18

how does dehydration lead to ADH release?

Answer 18

dehydration = increased plasma osmolarity

detected by osmoreceptors in the hypothalamus

stimulates nerves = secretion of ADH

Question 19

what is the plasma half life of ADH?

Answer 19

10-15 minutes

Question 20

what is the effect of high ADH?

Answer 20

increases water permeability 
hypertonic urine (very concentrated)

Question 21

what is the effect of low ADH?

Answer 21

low water permeability 
hypotonic urine (very dilute)

Question 22

what is aldosterone?

Answer 22

a steroid hormone secreted by the adrenal cortex

Question 23

when is aldosterone secreted?

Answer 23

response to rising K+ or falling Na+

after activation of the RAAS

Question 24

what does aldosterone stimulate?

Answer 24

sodium reabsorption

potassium secretion

Question 25

what does sodium retention due to aldosterone contribute to?

Answer 25

increased blood pressure

Question 26

what is another name for ANH?

Answer 26

atrial natriuretic peptide

Question 27

what produces ANP?

Answer 27

the heart

stored in atrial muscle cells

Question 28

when is ANP released?

Answer 28

when the heart cells are stretched due to increased plasma volume

Question 29

what does ANP promote?

Answer 29

excretion of Na+ and diuresis

= decreased plasma volume

Question 30

what is the process by which urine is emptied from the bladder?

Answer 30

micturition

Question 31

what are the two mechanisms that control micturition?

Answer 31

the micturition reflex

voluntary control

Question 32

what is the micturition reflex?

Answer 32

involuntary emptying of the bladder triggered by stretching of the bladder wall, picked up by stretch receptors