Renal and Urological System Facts

Question 1

primary function of kidneys and how do they do this

Answer 1

maintain stable internal environment for optimal cell and tissue metabolism

balance solutes and water
excreting metabolic waste
conserving nutrients
regulating acids and bases

Question 2

explain the endocrine function of the kidneys

Answer 2

secretes hormones
* renin for regulation of bp
* erythropoetin for RBC production
* vitamin D3 for calcium metabolism

Question 3

3 types of nephrons

Answer 3

cortical nephron
* 85% of all nephrons
* extend partially into the medulla
midcortical nephron
* short or long loops
juxtamedullary nephrons
* 12% of nephrons
* lie close to and extend deep into the medulla
* important for concentration of urine

Question 4

kidneys receive _____ to _____ ml of blood per minute or about _____ to _____% of cardiac output

Answer 4

1000ml
1200ml
20%
25%

Question 5

normal hematocrit level

Answer 5

45%

Question 6

_____ to _____ ml of blood flowing through the kidney per minute is plasma

Answer 6

600ml
700ml

Question 7

renal plasma flow is ____ to ____ ml/min or ____ L/day

results in about ____ L of urine/day

Answer 7

120ml
140ml
180L

1-2L

Question 8

glomerular filtration rate (GFR) is directly related to

Answer 8

perfusion pressure of the glomerular capillaries
renal blood flow (RBF)
this mean that if arterial pressure decreases or vascular resistance increases:
*RBF declines
*urine output decreases
*minimal urine output is 30mL/hour

Question 9

minimal urine output is _____ mL/hour

Answer 9

30mL/hr

Question 10

excretion (elimination of urine) is created by

Answer 10

glomerular filtration
tubular reabsorption
tubular secretion

Question 11

GFR forces of function

Answer 11

favoring force:
glomerular hydrostatic pressure
*relatively impermeable to large molecules (albumin)

opposing forces:
hydrostatic pressure in Bowman’s capsule
plasma oncotic pressure

Question 12

net effect of forces in the glomerulus

Answer 12

move water/solutes into Bowman’s capsule which creates primary urine

Question 13

hydrostatic pressure is ______ pressure, and oncotic pressure is ______ pressure

Answer 13

pushing
pulling

Question 14

what is filtered and reabsorbed in the glomerulus

Answer 14

water
generally free of protein and other blood cells
other substances in same concentration as plasma
*all electrolytes
*organic molecules:
creatinine
urea
glucose

Question 15

reabsorption is when

Answer 15

particles and water move from tubule into the plasma

Question 16

secretion is when

Answer 16

particles move from plasma into tubule

Question 17

examples of substances initially reabsorbed, but then eventually secreted again

Answer 17

H+ ions
Na
K
*based on plasma levels and presence of hormones (ADH)

Question 18

urine composition

Answer 18

clear, yellow, or amber
cloudiness may indicate bacteria, cells, or high solute concentration
pH ranges from 4.6 to 8, but normally acidic (provides protection against bacteria)
specific gravity (concentration of final urine): 1.001 to 1.0035
normally no glucose or blood cells
occasional protein

Question 19

vitamin D obtained from
requires _____ to activate

Answer 19

diet or the sun
*inactive form
*requires two hydroxylations in liver/kidney to activate

Question 20

parathyroid hormone (PTH) used when ____ deficiency to restore ____ levels

Answer 20

vitamin D
calcium

Question 21

erythropoietin produced by

Answer 21

peritubular fibroblast-like cells

Question 22

anemia in kidney failure is due to inability to produce ____

Answer 22

erythropoietin

Question 23

path of urea in system

Answer 23

50% excreted in urine
50% recycled in the kidney

Question 24

protein deprivation causes

Answer 24

inability to maximally concentrate urine