Glomerular Filtration Flashcards Preview

BIOL 314 Exam 4 > Glomerular Filtration > Flashcards

Flashcards in Glomerular Filtration Deck (43)
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1
Q

glomerular filtration creates

A

a plasma like filtrate of blood

2
Q

glomerular filtrate description of formation

A

water and substances that are dissolved in blood plasma get forced out of the glomerular capillaries into Bowman’s capsule and form glomerular filtrate

3
Q

composition of glomerular filtrate

A

consists of water, electrolytes, glucose, fatty acids, amino acids, vitamins, and nitrogenous wastes

4
Q

are formed elements and proteins in the filtrate?

A

no, they are too big to leave the blood vessels.

5
Q

how is the filtration membrane formed

A

endothelial cells in glomerular capillaries join podocytes to form a filtration membrane that filters water and small solutes, but not plasma proteins or formed elements

6
Q

glomerular endothelial cells

A

have large fenestrations through which solutes pass

7
Q

basement membrane

A

restricts passage of particles due to their size and their electronegativity

8
Q

large plasma proteins

A

like albumins, are too big to pass through the membrane; glomerular filtrate is only 0.3% protein while blood plasma is 7% protein

9
Q

pedicels

A

foot-like extensions from podocytes that wrap around glomerular capillaries to form filtration slits that can block passage of negative ions

10
Q

kidney infection or kidney trauma

A

can damage the filtration membrane and allow plasma proteins and/or formed elements to enter the filtrate causing proteinuria and hematuria

11
Q

what principles does glomerular filtration follow

A

the same principals that govern capillary bulk flow, but glomerular filtration involves much more fluid

12
Q

glomerular capillaries

A

long and provide large surface area for filtration

13
Q

filtration membrane

A

thin and porous

14
Q

blood pressure in glomerular capillaries

A

is high

15
Q

glomerular blood hydrostatic pressure

A

GBHP- the main force responsible for moving water and solutes out of blood plasma through the filtration membrane

16
Q

capsular hydrostatic pressure

A

CHP- opposes additional filtration because there is a high rate of filtration and because fluid is already present in the renal tubule

17
Q

blood colloid osmotic pressure

A

BCOP- also opposes filtration because of the plasma proteins that are present in blood plasma

18
Q

net filtration pressure promotes

A

filtration out of the glomerular capillaries

19
Q

NFP=

A

GBHP - (CHP + BCOP)

20
Q

glomerular filtration rate

A

GFR- refers to the amount of filtrate that is formed per minute in all of the renal corpuscles of both kidneys

21
Q

GFR for males

A

125 mL/min; which produces 180L of filtrate per day

22
Q

GFR for females

A

105 mL/min; which produces 150L of filtrate per day

23
Q

GFR relationship to NFP

A

GFR is directly proportional to NFP, so changes in GBHP, CHP, or BCOP will affect GFR

24
Q

if the GFR is too high

A

filtrate will flow through the renal tubules too quickly for them to reabsorb water and solutes

25
Q

urinary output (if GFR is too high)

A

rises and creates a risk for becoming dehydrated

26
Q

if the GFR is too low

A

filtrate will flow through the renal tubules too slowly and wastes will get reabsorbed

27
Q

risk of GFR being too low

A

creates a risk for developing azotemia

28
Q

renal autoregulation

A

the ability of the kidneys to maintain constant renal blood flow and glomerular filtration despite changes in arterial blood pressure

29
Q

myogenic mechanism

A

occurs when arterial blood pressure changes, which affects smooth muscle cells in walls of afferent arterioles

30
Q

when blood pressure rises

A

smooth muscle fibers contract and constrict afferent arteriole, which decreases blood flow into glomerulus to reduce GFR

31
Q

when blood pressure drops

A

smooth muscle fibers relax and dilate afferent arteriole, which increases blood flow into glomerulus to raise GFR

32
Q

tubuloglomerular feedback involves the

A

juxtaglomerular apparatus

33
Q

when GFR is elevated

A

filtrate flows through renal tubule too fast to reabsorb enough NaCl

34
Q

macula densa cells

A

release vasoconstrictor that reduces flow of blood from afferent arteriole into glomerulus to reduce GFR

35
Q

when GFR falls

A

flow of blood from afferent arteriole into glomerulus is increased

36
Q

autoregulation and changes in GFR

A

autoregulation does not completely block changes in GFR, but it allows for fluctuations within narrow limits

37
Q

autoregulation and variations in blood pressure

A

autoregulation cannot compensate for extreme variations in blood pressure but it will prevent large changes in water and solute excretion

38
Q

neural regulation

A

uses sympathetic nerve fibers to send signals to afferent arterioles that constrict them and decrease the flow of blood into the glomerular capillaries in order to reduce GFR and maintain systemic blood pressure

39
Q

the renin-angiotensin mechanism

A

is activated by a drop in blood pressure

40
Q

juxtaglomerular cells

A

secrete renin (an enzyme), which triggers conversion of angiotensinogen to angiotensin II

41
Q

angiotensin II constricts

A

both afferent and efferent arterioles to reduce GFR

42
Q

angiotensin II stimulates adrenal cortex to

A

secrete aldosterone to promote water retention and sodium retention

43
Q

angiotensin II stimulates pituitary gland to

A

secrete ADH to increase water absorption