Lecture 14 Body Fluids

Question 1

Layers of the filtration barrier

Answer 1

endothelium
basement membrane
podocytes

Question 2

Endothelium of filtration barrier

Answer 2

part of the capillaries, first layer of filtration barrier

fenestrae with negative charges

Question 3

basement membrane of filtration barrier

Answer 3

composed of collagen and proteoglycan fibers with strong negative charges

meshwork formed by collagen and proteoglycan makes a filtration

Question 4

podocytes of filtration barrier

Answer 4

create a filtration slit with negative charges

Question 5

albumin in urine

Answer 5

albumin is the most popular protein in blood, presence would indicate damage and infection in the filtration barrier

blood cells aren’t supposed to pass

Question 6

Globular filtration rate is determined by

Answer 6

balance of hydrostatic and colloid osmotic forces acting across the capillary membrane

basically starling forces

Question 7

capillary filtration coefficent

Answer 7

product of permeability and filtering surface area of the capillaries (K1)

depends on the number and size of the pores in the capillary

Question 8

what is the average GFR per day?

Answer 8

125 mL/min

180 L/day

Question 9

what are some diseases that effect the lower glomerular capillary filtration coefficient

Answer 9

chronic uncontrolled hypertension and diabetes mellitus

Question 10

define minimal change nephropathy

Answer 10

loss of negative charge in the basement membrane

Question 11

define hyronephrosis

Answer 11

dissension and dilation of renal pelvis and calyces

Question 12

GFR equation

Answer 12

GFR = K1 x Net Filration pressure

GFR = K1 x (P g -P b - Pi g + Pi b)

Question 13

relationship between K1 and GFR

Answer 13

directly proportional

increase in K1 increases GFR
decrease in K1 reduces GFR

Question 14

factors that influence glomerular capillary colloid osmotic pressure

Answer 14

arterial pressure colloid osmotic pressure

filtration fraction

Question 15

factors that increase glomerular colloid osmotic pressure

Answer 15

increasing filtration fraction

Question 16

variables that determine glomerular hydrostatic pressure

Answer 16

arterial pressure
afferent arteriolar resistance
efferent arteriolar resistance

Question 17

arterial pressure impact on glomerular hydrostatic pressure

Answer 17

increase in AP causes increase in Pg which increases GFR

Question 18

afferent arteriolar resistance

blood isn’t coming in

Answer 18

increase in AAR causes decrease in Pg which decrease GFR

Question 19

efferent arteriolar resistance

clamping off the efferent arteriole – blood is still coming in but not going out

Answer 19

increase in EAR causes increase in Pg which increases the GFR

Question 20

Where does most of the O2 consumed by the kidneys become used?

Answer 20

active reabsorption of Na

utilizing ATP to absorb Na

Question 21

Do kidneys or brain have more blood flow?

Answer 21

kidneys have 7x blood flow but only 2x oxygen consumption

Question 22

activation of renal sympathetic nerves…

Answer 22

constricts the renal arterioles

decreases renal blood flow and GFR

Question 23

innervation of blood vessels in the kidney

Answer 23

sympathetic

Question 24

hormones that control GFR consistency (7)

Answer 24

norepinephrine and epinephrine
endothelin
angiotensin ii 
endothelial derived nitric oxide
prostaglandins 
bradykinin

Question 25

norepinephrine and epinephrine

Answer 25

from adrenal medulla

parallels the sympathetic nervous system

Question 26

endothelin

Answer 26

released by damaged vascular endothelial cells of kidneys and other tissues

contribute to renal vasoconstriction (decrease gFR)
contributed to hemostasis if blood vessel is severed

plasma levels will increase in certain disease states associated with vascular injury (toxemia or pregnancy, acute renal failure, chronic uremia)

Question 27

angiotensin II

Answer 27

preferentially constricts efferent arterioles
formed in situations associated with decreased arterial pressure or volume depletion (increases GFR via efferent arterials)

afferent arterioles seem to be protected against angiotensin II (release vasodilators via prostaglandins and NO)

Question 28

nitric oxide

Answer 28

via endothelial cells

helps maintain renal vasodilation

Question 29

prostaglandins and bradykinin

Answer 29

vasodilators may offset effects of sympathetic and angiotensin II vasoconstrictor effects (esp. afferent arterioles)

Question 30

auto regulation

Answer 30

relative constancy of GFR and renal blood flow

maintains a relatively constant GFR
allows precise control of renal exertion of water and solutes
prevents large changes in GFR and renal extortion that would occur with change in blood pressure

Question 31

two components of tubuloglomerular feedback mechanism

Answer 31

afferent arteriolar feedback mechanism

efferent arteriolar feedback mechanism

Question 32

juxtaglomerular complex

Answer 32

macula densa in distal tubule (reads [NaCl])

juxtaglomular cells in afferent and efferent arterioles

Question 33

decrease in GFR causes a slow rate in loop of Henle therefore

Answer 33

increased reabsorption of sodium and chloride ions in ascending limb
decrease in sodium chloride at macula dense

Question 34

decrease in [NaCl] results in a signal from macula dense

Answer 34

decreases resistance to blood in afferent arterioles
increase renin release from JG cells
increase angiotensin II
increase efferent arteriolar resistance