kidney function 3

Question 1

how is constant plasma osomolality maintained ?

Answer 1

• urine formation

- thrist

Question 2

what is concentrated urine ?

Answer 2

• anything above 300 mosmol/kg

Question 3

what is obligatory water loss ?

Answer 3

0.428L/day

Question 4

what is oliguria ?

Answer 4

urine output below 300mosmol/kg

Question 5

what is dilute urine ?

Answer 5

• anything below 300 mosmol/l

- lots of water in urine

Question 6

what is anti-diuresis ?

Answer 6

low volume of urine

Question 7

what happens when the body is dehydrated ?

Answer 7

• increased plasma osmoolality
• stimulates osmoreceptors in hyptohalamus
• causes posterior pituitary to release more ADH
• means increased water reabsorption in the kidneys
• less water excreted in urine

Question 8

what is diuresis ?

Answer 8

large volume of urine

Question 9

what happens when the body is over- hydrated ?

Answer 9

• decreased plasma osmolality
• stimulates osmoreceptors in the hypothalamus
• posterior pituitary releases less ADH
• causes kidneys to decrease water reabsorption
• more water excreted in urine

Question 10

what is osmolar clearance ?

Answer 10

the clearance of all osmotically active particles in the plasma

Question 11

where do osmoreceptors signal to ?

Answer 11

paraventricular and supraoptic nuclei in hypothalamus

Question 12

what controls ADH secretion ?

Answer 12

• plasma osmolality
• neural control
• hormonal control

Question 13

what hormones increase ADH secretion ?

Answer 13

angiotensin II

Question 14

what hormones decrease ADH secretion ?

Answer 14

natriuretic peptides

Question 15

what other factors effect ADH levels ?

how do they effect ADH ?

Answer 15

pain ( stimulates) 
nausea (stimulates) 
nicotine (stimulates) 
stress (stimulates)
alcohol ( inhibits)

Question 16

what is water diuresis

Answer 16

dilute urine

lots of water in it

Question 17

what is osmotic diuresis

Answer 17

abnormal concentrations of solute in urine

Question 18

what are the characteristics of diabetes insipidus ?

Answer 18

• urination
• thirst
• nocturia

Question 19

what are the 2 types of diabetes insipidus ?

Answer 19

• neurogenic (no ADH secreted) can be congenital or due to trauma
• nephrogenic (ADH present but kidneys dont respond to it) can be inherited or acquired

Question 20

what are the characteristics of osmotic diuresis ?

Answer 20

• urination

- thirst

Question 21

how is potassium maintained ?

Answer 21

• renal excretion
• gastrointestinal loses
• cellular shifts

Question 22

what is hypokalaemia ?

Answer 22

lower than normal level of potassium in blood

Question 23

what is hypokalaemia caused by ?

Answer 23

• increased external losses of potassium
• redistribution of potassium into cells
• inadequate potassium intake

Question 24

what are the boundaries for hypokalaemia ?

Answer 24

• mild: 3.0-3.5
• moderate: 2.5-3.0
• severe: < 2.5

Question 25

what are symptoms associated with hypokalemia ?

Answer 25

- irregular heartbeat - weakness, paralysis of muscles - nausea and vomitting - polyuria

Question 26

how can you treat hypokalemia ?

Answer 26

- eat foods rich in potassium - administer KCL - correct alkalosis

Question 27

what is hyperkalaemia ?

Answer 27

too much potassium in the urine

Question 28

what causes hyperkalemia ?

Answer 28

decreased external losses | redistribution out of cells

Question 29

what are the boundaries of hyperkalemia ?

Answer 29

- mild : 5.5-6.5 - moderate: 6.5- 7.5 - severe > 7.5

Question 30

what are symptoms of hyperkalemia ?

Answer 30

- irregular heartbeat - weakness and paralysis of muscles - nausea and vomiting

Question 31

how can you treat hyperkalemia ?

Answer 31

- stabilize the cardiac membrane - fix potassium shift into cells - long term potassium will need to be removed from the body