ANP 1107A Renal Lecture 4

Question 1

what is urinary retention?

Answer 1

inability to expel urine

• after general anaesthesia, can also result from prostate hypertrophy

Question 2

what is renal failure?

Answer 2

this happens when there are not enough functioning nephrons

• filtrate formation has been reduced or stopped

Question 3

what is stress incontinence?

Answer 3

anything that increases intra abdominal pressure, it’s a sharp push on the bladder and pushes a bit of urine out

• an example is cough or sneeze

Question 4

The regulation of micturition

Answer 4

3 things have to happen

1. detruser muscle must contract
2. Internal ureathral sphincter must open
3. External urethral sphincter must open

Question 5

what is incontinence?

Answer 5

inability to control urine voluntarily

• due to a weakened pelvic floor muscles, pressure of pregnancy, nervous system problems

Question 6

what are potential causes to renal failure?

Answer 6

repeated damaging kidney infections

physical injuries to kidneys

prolonged pressure on skeletal muscles

inadequate blood delivery to tubules

Question 7

what is diarrhea?

Answer 7

nitrogenous wastes accumulate & blood becomes acidic

Question 8

what is hemodialysis?

Answer 8

A technique in which an artificial kidney machine removes waste products from the blood

• can be done in a clinic or at home – several times a week for 3-5 hr/session

Question 9

what is peritoneal dialysis?

Answer 9

works by using the blood vessels of the peritoneal membrane

Question 10

where can peritoneal dialysis be done at?

Answer 10

can be done at home or work

• does not require weekly hospital visits

Question 11

what happens in peritoneal dialysis?

Answer 11

dialysate is infused into the peritoneal cavity through a catheter

dialysatec omposed mostly of salts and sugar

encourages filtration through the peritoneum

Question 12

what is removed?

Answer 12

extra fluid and wastes is drawn from the blood into dialysate which is then removed

Question 13

what are the two types of peritoneal dialysis?

Answer 13

continuous ambulatory peritoneal dialysis (CAPD)

continuous cycling peritoneal dialysis (CCPD)

Question 14

what are the two types of peritoneal dialysis?

Answer 14

continuous ambulatory peritoneal dialysis (CAPD)

continuous cycling peritoneal dialysis (CCPD)

Question 15

what happens in continuous ambulatory peritoneal dialysis (CAPD)

Answer 15

happens usually 4-5 times/day

patient puts dialysate (about two litres) into peritoneal cavity through catheter

dialysate stays there for 4-5 hours before it is drained back into the back and thrown away.

there is a new bag of dialysate for each exchange

Question 16

what happens in continuous cycling peritoneal dialysis (CCPD)

Answer 16

usually is done at home using a special machine called a cycler

number of cycles (exchanges) occur

each cycle is 1-1/2 long and exchanges occur during the night while the patient is asleep

Question 17

what is the intracellular fluid compartment (ICF)

Answer 17

fluid within cells

= 60% total body fluid

Question 18

what is the extracellular fluid compartment (ECF)

Answer 18

fluid outside of cells

= 40% body fluid

Question 19

two components of extracellular fluid

Answer 19

plasma and interstitial fluid

plasma = 20% of ECF

Interstitial fluid = 80%

Question 20

in ECF what is the chief cation?

Answer 20

sodium

Na+

Question 21

in ECF what is the chief anion?

Answer 21

chloride

Question 22

water intake must equal

Answer 22

water output

Question 23

what are some examples of water intake?

Answer 23

liquids, foods, cellular metabolism

Question 24

what are some examples of water output?

Answer 24

~60% via kidneys; also lungs, skin, sweat, feces, lungs (add moisture to the air)

Question 25

what number are we trying to get plasma osmolarity?

Answer 25

usually 280-300 mOsm

Question 26

what happens if plasma osmolarity goes above 300 mOsm?

Answer 26

you feel thirsty - increase water intake ADH stimulates renal water reabsorption

Question 27

what happens in decreased osmolarity?

Answer 27

thirst not stimulated ADH secretion is not stimulated

Question 28

what happens in increase in osmolarity 1-2%?

Answer 28

reduce saliva production (makes you dry) osmoreceptors of the hypothalamic thirst center lose water to the hypertonic ECG (depolarize and become irritable)

Question 29

what happens in decrease in plasma volume of 5-10%?

Answer 29

baroreceptors - also triggers the thirst mechanism

Question 30

what is dampening of thirst?

Answer 30

it begins once mucosa of mouth & throat moistened by water, it prevents overdrinking while water moves to ECF

Question 31

what are the obligatory water losses?

Answer 31

insensible water loss via lungs/skin via the feces minimal sensible urinary loss = 500 ml/day

Question 32

what is dehydration?

Answer 32

can be loss of only fluid or loss of fluid plus salts consequence = cells swell

Question 33

what is hypotonic hydration?

Answer 33

dilutes out sodium in ECF, causing water to move into cells

Question 34

what is edema?

Answer 34

accumulation of fluid (including salts) in IF, but not inside cells consequences = cells swell

Question 35

salt content of the body can vary due to?

Answer 35

diet, sweating, vomiting, etc.

Question 36

what does Na+ determine

Answer 36

determines both plasma osmolarity and blood volume

Question 37

sodium content of the body may change

Answer 37

but its concentration in ECF is monitored and usually remains stable due to immediate adjustments in water volume

Question 38

what happens to blood pressure after a salty meal?

Answer 38

blood pressure goes up

Question 39

what is aldosterone

Answer 39

most influential agent at level of kidney; acts slowly

Question 40

even without aldosterone what happens?

Answer 40

65% of Na+ in filtrate reabsorbed in PCT & 25% in loop of Henle; aldosterone secretion essential to life

Question 41

what is high aldosterone?

Answer 41

virtually all remaining Na+ (chloride co-transported) actively reabsorbed by DCT & collecting ducts

Question 42

2 pathways to aldosterone secretion

Answer 42

renin-angiotensin system direct effect of high K+ or low Na+

Question 43

renin secretion in response

Answer 43

sympathetic ns decreased filtrate osmolarity decreased stretch bp

Question 44

what is Addison's disease?

Answer 44

autoimmune hyposecretion of aldosterone - excess loss of Na+ & water in urine - only pull back 90%

Question 45

water reabsorption in collecting ducts relies on?

Answer 45

relies on ADH secretion and will influence plasma sodium secretion

Question 46

what happens in low Na+?

Answer 46

excess fluid, reduced ADH secretion & dilute urine to unload water

Question 47

what happens in high Na+?

Answer 47

decreased blood volume and not enough water for correct osmolality, increased ADH secretion & reduced urine volume to move water back into bloodstream

Question 48

what is atrial natriuretic factor released by

Answer 48

released by cells in the atria of heart when bp is elevated

Question 49

what do potent diuretic & natriuretic hormone do

Answer 49

(i) inhibits Na+ reabsorption by DCT and collecting duct (ii) decrease released of ADH, renin, and aldosterone (iii) induces vasodilation overall effect is to reduce bp

Question 50

what is pressure diuresis

Answer 50

when blood pressure/volume increases, sympathetic output to kidney from cardiovascular centre

Question 51

what is the result of pressure diuresis

Answer 51

dilation of afferent arterioles and increase GFR