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Flashcards in Phys: Renal Deck (45)
1

what are the main functions of the kidney?

waste excretion
electrolyte balance
BP control
acid base balance

2

what is the functional unit of the kidney?

the nephron

3

explain the kidney:

it is an excretory organ with an ENDOCRINE fxn.
it has 2 parts:
Cortex
Medulla

4

what are the 2 types of nephrons? how many nephrons in thebody?

Cortical- 80%
Juxta-medullary- 20%
nearly 1 million nephrons in the body. Cannot be regenerated.

5

what makes up the nephron?

Glomerulus- enveloped in a double layer Bowmans capsule
Two convuluted tubules- proximal & distal
two parts of the Loop of henle- two parts a thick and thin ascending, and a thin descending

6

what are the 2 hormones that are secreted by the kidney?

erythropoeitin
renin

7

what hormones act on the kidney?

ADH
Aldosterone
ANP
1,25 dihydroxycalciferol
parathormone

8

the kidneys function is dependent on?

blood flow

9

how much does the kidney use of the cardiac out put?

20% (1 liter/min)

10

how much of the renal blood flow is the renal PLASMA flow?

60% (600 mL/minute)

11

course of blood flow in the kidney?

Renal art> interlobar> arcuate> interlobULAR> Afferent arteriole (in)> Glomerulus> Efferent arteriole (out)> peritubular cap.> Venules> interlobUlar vein> Arcuate vein> interlobar vein> renal vein> IVC

12

urine flow?

collecting duct> Calyx> renal pelvis> Ureter> bladder> urethra

13

how much do you filtrate a day?

180 L

14

purpose of bowmans capsule?

filtration due to fenestrations
pressure is -18 mm Hg
it pushes water back into the capillary

15

proximal tubule fxn?

reabsorption
100% of AA & glucose are filtered here
80% of bicarbonate & phoshate
60-70% of Na+ (exchanged for H+), Ca++, K+
50% H2O and urea

16

podocytes are?

cells that form filtration membrane

17

loop of henle fxn?

concentration

18

vasa recta are?

thin-walled vessels, parallel loop of henle

19

distal tubule does?

aldosterone works here to reabsorb Na+ and secrete K+

20

reabsorption of filtrate in prox. tubule? distal tubule?

65% end of prox.
99% end of distal

21

what is the normal GFR?

120-125 mL/min
determined by hydrostatic pressure

22

what does hyrdostatic pressure?

pushes water out of the capillary (+60 mm Hg)

23

what does oncotic pressure do?

pulls water back into capillary (-32 mm Hg)

24

what is the renal threshold for glucose?

180 mg/dL- once reached glucose will pass through the urine

25

what is the thin descending loop of henle permeable to?impermeable? purpose?

H2O
impermeable: urea
P: concentrate the urine

26

what is the thick ascending part impermeable to? purpose?

H2O
it is the diluting segment of the loop

27

what are juxtaglomerular cells for?

mechanoreceptors for BP entrance afferent arteiole

28

what are macula densa for?

chemoreceptors for JG cells
sensitive to Na+ conc.
located in the DCT

29

Aldosterone is from? purpose?

from Zona Glomerulosa
absorbs Na+, excretes K+
results from RA system
thus water

30

renin is from? stimulated by?

JG apparatus
stim. by dec. in pressure in afferent arterioles

31

erythropoeitin does?

RBC production

32

why is the RAA system stimulated? explain

drop in BP
Renin-Angiotensin- Aldosterone system
Angiotensinogen- protein produced in liver
Renin- enzyme made by JG cells
Angiotensin I- travels in blood
ACE- made in lungs (converts angio I into angio II)
Angiotensin II- constricts BV (inc. BP), stimulates release of- Aldosterone- inc. bp by inc. Na+ reabsorption

33

renin converts?

angitoensinogen> angintensin I

34

ACE converts?

angiotensin I> angitensin II

35

respiratory acidosis is? cause? compensate?

inc pCO2 & dec pH
HYPOventilation: COPD & CHF
renal: inc H+, inc HCO3-

36

respiratory alkalosis is? cause? compensate?

dec. pCO2 & inc pH
HYPERventilation
renal: dec. H+, dec. HCO3-

37

Metabolic acidosis is? cause? compensate?

dec. HCO3-, dec. pH
diarrhea, diabetic ketoacidosis, renal dysfx, Aspirin overdose
respiratory:Hyperventilation

38

metabolic alkalosis is? cause? compensate?

inc. HCO3-, inc pH
drugs, vomiting, diuretics: conns disease
respiratory: hypoventilation

39

what does ADH do?

increases water perm in the collecting ducts by acting on the aquaporins
secreted by supra-optic nucleus in the hypothalamus

40

what does ANP do?

decrease Na+ reabsorption in the DCT; results in increased urine ouput
peptide hormone produced in the atrial myocardial fibers

41

what does 1,25 dihydroxycarboxylase do?

acts on DCT by increasing Ca++ absorption
it is the active form of Vit. D

42

what is the pH of the blood?

7.35-7.45

43

what is volatile acid?

produced when CO2 reacts with h2O to form carbonic acid

44

what are examples non-volatile acid?

lactic acid
suulfuric acid
phosphoric acid
keto-acids-acetone
acetoacetate
hydroxybutrate

45

what is the major buffer in the blood?

bicarbonate