Kidneys Flashcards Preview

Nursing > Kidneys > Flashcards

Flashcards in Kidneys Deck (26):
1

% of CO kidneys receive

20-25%

2

how much fluid do the kidneys prod?

1200ml/min

3

primary/secondary functions of kidney

1o → regulate vol and composition of body fluids

2o → syn vit D, BP reg, EPO syn, BGL reg

4

% of nephrons in cortex

80-85%

5

glomerulus capillary divisions

capillary divisions of renal A → glomerular capillaries → efferent arterioles → vasa recta → drains into venules → renal vein → IVC

6

what is GFR dependent on?

- net filtration pressure
- total surface area
- filtration membrane permeability

7

PCT reabs

contains brush border

reabs:
- 2/3 filtered Na and h2o
- ALL glucose and AA
- fraction of bicarbonate, k, p ,ca

8

PCT secretion

NH3 (buffer for H+)
creatinine

9

LoH descending limb

thin
- reabs h2o
- impermeable to Na → concentrates urine (Hypertonic)

10

LoH ascending limb

thick
- na, k, cl actively reabs
- impermeable to h2o → less concentrated urine

11

DT reabs

- na (less than PCT) ACTIVELY
- relatively impermeable to h2o → dec concentration

- regulated by hormones

12

Collecting duct - principal cells

- reabs na + h2o
- secretes k
- regulated by ADH and aldosterone

13

Collecting duct - intercalated cells

- reabs K ACTIVELY
- secretes H

14

ADH

secreted by POS pit
- inc permeability to H2o (inc reabs) → concentrates urine

15

ANH

secreted by atria of heart
- inc natriuresis (secretion of Na)

16

aldosterone

- inc ACTIVE reabs of na AND secretion K (leads to hypokalemia)

17

spironolactone

- inhibit na reabs in DT
- blocks Na channels and aldosterone release
- leads to Na excretion and K retention

18

flow of urine fromkidneys

papilla → minor calyx → major → renal pelvis → ureter → bladder...

19

how do ureters enter bladder

oblique entrance
- prevents vesicoureteral reflux

20

what is the capacity of the bladder

300-500ml

21

micturition reflex

bladder fills ~200-300ml → stretch wall → stretch R → micturition centers → PNS

- PNS stimulates detrusor contraction & internal urinary sphincter relaxation (invol)
- external urinary sphincter VOLUNTARY relax

22

autoregulation of GFR

1) macula densa in DT sense dec GFR
2) JGC (granular cells) in afferent arteriole secrete renin
3) renin → angiotensinogen → ANG 1 → 2 → VC afferent tubules → inc GFR

23

composition of urine

water = 95%
solutes (urea, uric acid, creatinine) = 5%

pH~6

24

main issue with renal system in childhood to middle age

associated with infections

25

GFR at birth → 2yrs

lower

26

ageing and renal system

- dec function →dec size, nephrons, tubular cells efficiency
- dec renal BF (~10%/decade)
- inc glomerular basement membrane permeability → inc urinary excretion of proteins
- changes of response to vasoactive mediators (inc VC stim, dec VD stim)