L17: Micturation & Glomular Filtration

Question 1

sensory signals from bladder stretch receptors are conducted ________ back to bladder via _______ nerves.

Answer 1

reflexively

parasympathetic

Question 2

reflex contractions will ____ ________ when the bladder is half full

Answer 2

stop spontaneously

Question 3

as the bladder continues to fill micturition reflexes will ?

Answer 3

occur more often and more intense

Question 4

higher brain centers, in the _____, keep urination partially ________ until it is a desired event.

Answer 4

pons

partially inhibited

Question 5

when it is time urinate, what helps facilitates reflexes and relax external sphincters.

Answer 5

cortical centers

Question 6

how do nephrons regulate arterial pressure long term

Answer 6

excrete variable amounts of Na and water

Question 7

how do nephrons regulate arterial pressure short term

Answer 7

secrete hormones and vasoactive factors such as renin

Question 8

how do nephrons regulate acid-base balance

Answer 8

by excreting acids to regulate body fluid buffer stores
and
eliminate wastes created by protein metabolism - urea

Question 9

list the 3 processes done by nephrons that determine urine composition

Answer 9

filtration
reabsorption
secretion

Question 10

urinary excretion rate =

Answer 10

filtration rate - reabsorption rate + secretion rate

Question 11

what are the major components of glomerular filtrate

Answer 11

water
ions
glucose
urea

Question 12

filtration fraction =

Answer 12

GFR/renal plasma flow

Question 13

define filtration fraction

Answer 13

if it = 0.2

then means 20% of plasma flowing thru kidney is filtered

Question 14

low molecular weight substances are not freely filtered since ?

Answer 14

they are partially bound to proteins

Question 15

what are the 3 components of the filtration barrier

Answer 15

endothelium
basement membrane
podocytes

Question 16

filtration barrier endothelium

Answer 16

have fenestrae and negative charges

Question 17

filtration barrier BM

Answer 17

collagen
proteoglycan fibers
strong negative charges

Question 18

filtration barrier podocytes

Answer 18

negatively charged

Question 19

2 factors that determine GFR

Answer 19

1. balance of hydrostatic and colloid osmotic forces acting on capillary membranes
2. capillary filtration coefficient

Question 20

define capillary coefficient

Answer 20

= K1

the product of permeability and filtering surface area of capillaries

Question 21

normal GFR

Answer 21

125 mL/min
or
180 L/day

Question 22

diseases that lower glomerular capillary filtration coefficient

Answer 22

chronic uncontrolled hypertension

diabetes mellitus

Question 23

define minimal change nephropathy

Answer 23

loss of negative charges on the BM

Question 24

define hydronephrosis

Answer 24

distension and dilation of renal pelvis and calyses

Question 25

express GFR in starling forces

Answer 25

GFR = K1 x net filtration pressure GFR = K1 x (60-18-32+0)

Question 26

relate K1 to GFR

Answer 26

K1 = GFR/net filtration pressure

Question 27

K1 is _____ related to GFR

Answer 27

directly increase k1 = increased GFR and vice versa

Question 28

2 factors that effect glomerular capillary colloid osmotic pressure

Answer 28

arterial plasma colloid osmotic pressure filtration fraction

Question 29

what increases GCCOP

Answer 29

increasing filtration fraction

Question 30

3 variables that determine glomerular hydrostatic pressure

Answer 30

arterial pressure afferent & efferent arteriole resistance

Question 31

kidney blood flow is ___ as much as brain flow, but has ___ the O2 consumption. what is this related to ?

Answer 31

7x, 2x related to high rate of active Na absorption

Question 32

renal blood flow formula

Answer 32

(renal artery press. - renal vein press.) / total vascular resistance

Question 33

all BVs of kidneys are innervated by ?

Answer 33

sympathetic system

Question 34

strong action of _____ nerves to kidneys will result in ?

Answer 34

- -constriction of renal arterioles | - -decreased renal blood flow and GFR

Question 35

moderate nervous stimulation has ____ effect on kidneys

Answer 35

little effect

Question 36

norepinephrine and epinephrine are from

Answer 36

the adrenal medulla

Question 37

angiotensin II control of GFR

Answer 37

constricts efferent arterioles which helps to increase GFR

Question 38

in what situations in angiotensin II used to control GFR

Answer 38

--when arterial pressure is decreased or --volume depletion

Question 39

why does angiotensin II only effect ______ arterioles?

Answer 39

efferent | afferent arterioles are protected against this due to release of vasodilators prostaglandins, NO, bradykinin

Question 40

what is the source of endothelin

Answer 40

it is released by damaged vascular endothelial cells of kidneys

Question 41

how does endothelin help control GFR

Answer 41

helps w/ renal vasoconstriction to reduce GFR

Question 42

NO is derived from _____ cells, and helps ?

Answer 42

endothelial cells | helps maintain renal vasodilation

Question 43

prostaglandin and bradykinin are both _____. and work to offset the effects of ______ .

Answer 43

vasodilators offset effects of angiotensin II for the afferent arterioles

Question 44

define autoregulation

Answer 44

refers to the relative constancy of GFR and renal blood flow

Question 45

functions of autoregulation

Answer 45

- -maintain constant GFR - -precise control of renal excretion of water and solutes - -prevent large changes in GFR and renal excretion

Question 46

what is the importance of autoregulation

Answer 46

w/o it a slight increase in bp could increase GFR up to 225 L/day which would increase urination to 46.5 L/day

Question 47

what are the 2 components of autoregulation feedback mechanism

Answer 47

afferent and efferent arteriolar feedback

Question 48

the macula densa is found in the

Answer 48

distal tubule

Question 49

a decreased GFR will increase the reabsorption of what in the ascending limb and decrease what at macula densa?

Answer 49

Na and Cl NaCl

Question 50

what is the major storage of renin

Answer 50

juxtaglomerular complex