Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Topic 3 Exam 3 Kidney > Flashcards

Topic 3 Exam 3 Kidney Flashcards

1
Q

What are some of the purposes of the Kidneys?

A

regulate blood pressure,l ion balance, pH, removes wastes, secrete hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why filter so much blood?

A

maintain homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Path of blood through a nephron
(An
Apple
Gets
Even
perused
Every
Vay)

A

artery
afferent arteriole
glomerulus
efferent arteriole
peritubular capillaries\
Vasa Recta
Vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Path of Filtrate through a Nephron
Big
Butts
dont
ask
dumb
catty
cows

A

Blood
Bowman’s Capsule
Proximal Tubule
descending limb of LH
ascending limb of LH
distal tubule
collecting tubule
collecting duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Filtration

A

glomerulus to tubules, non-selective

based on size, like a coffee filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Reabsorption

A

lumen of tubules to blood, selective,

requires channels of transporters from filtrate

ex) glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Secretion

A

peritubular capillary blood to tubules, selective

requires channels of tranporters,

blood to filtrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Excretion

A

tubules to outside the body (via bladder)

outside the body (pee)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F Channels btw capillaries & tubules are not required for reabsorption and secretion

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the filtration formula?

A

F-R+S=E

Filtration-Reabsorption +Secretion= Excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mesangial Cells

A

Support and Regulate blood flow in glomerular capillaries

smooth muscle

respond to changes in pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Podocytes

A

spaces btw their foot processes (slits) form a filter

foot cells

wrap around capillary endothelial cells

slit pores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Capillary Endothelial Cells

A

smal gap pores called Fenestration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many layers of the Glomerular Membrane does Filtrate have to pass though

A

3
1) Capillary Endothelial Cell
2) Basement membrane
3) Epithelial Cell (podocyte)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much plasma volume is filtered into Bowman’s capusle?

A

~20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Glomerular Filtration Rate (GFR)

A

amount of plasma filtered per unit time
~125 mL/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is GFR determined by?

A

Glomerular FIltration Pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is GFP?

A

Glomerular Filtration Pressure

driving force for filtration and is the Sum of the Starling Forces:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pgc=

A

Capillary hydrostatic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pi bc=

A

capsule osmotic pressure

(0 under normal circumstances)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Pi gc

A

glomerular osmotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Pbc

A

Bowman’s Capsule Hydrostatic Pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What two factors favor filtration?

blood to filtrate?

A

Pgc=hydstatic pressure in glomerular capillaries

Pibc= osmotic pressure in Bowman’s Capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What two factors oppose filtration?

A

Pbc=hydrostatic pressure in Bowman’s Capsule

PiGc= Osmotic pressure in Glomerular Cappilaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The amount of a substance X that is excreted in Joe’s urine
increases. If the amount of the substance that was filtered did not
change, what caused this increase?

A

E = F – R + S
If F is constant and E went up, either less of substance X was reabsorbed or more was
secreted (the ratio of secretion relative to re-absorption went up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Substance Y cannot be reabsorbed or secreted. If the amount
of substance Y in the urine increases, what must have happened?

A

E = F – R + S
R and S are 0, so the only way to increase E is to increase F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

If the efferent arteriole from the glomerulus is constricted, what
happens to glomerular filtration pressure (GFP)? Why? What
happens to glomerular filtration rate (GFR)?

A

Constriction of the efferent arteriole will increase resistance and therefore increase GFP.
Increased GFP will cause increased GFR.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Steve’s blood albumin levels drop suddenly, what happens to
GFR? Why?

A

Remember that albumin is one of the most common proteins in the blood and is large such that it cannot cross capillary walls (including the glomerulus).

It is a critical
determinant of glomerular capillary osmotic pressure (πGC) which acts to reduce GFP.

Reduced blood albumin would therefore reduce πGC, leading to increased GFP and GFR.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Constant infusion of inulin for measurement of GFR is time-consuming and
expensive. In practice, creatinine is often used. It is naturally produced in
your body and is freely filtered. However, it is also secreted in small amounts.
Given this, will an estimate of GFR based on creatinine clearance be an
overestimate or an underestimate? Explain.

A

In using clearance of a substance to estimate GFR, you are assuming that it is freely
filtered and neither reabsorbed or secreted:

Excretion = Filtration – Reabsorption + Secretion

In the case of creatinine, there is a little bit of secretion (movement of creatinine from the
blood to the filtrate). This will increase the amount of creatinine detected in the urine,
leading to an overestimate of GFR.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

GFP=

A

Pgc+PIbc-Pbc-Pigc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How can GFR be a constant across a range of blood pressures?

A

the Zone of Autoregulation where the GFR stays stable from 80-180 MAP mmgh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Within the zone of autoregulation, there are 3 mechanisms of
intrinsic control……

A

1) Myogenic Regulation
2) Tubuloglomerular Feedback
3) Mesangial Cell Contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Myogenic Regulation

A

Smooth Muscle of the afferent arteriole contracts when it is stretched

increased arterial pressure stretches the afferent arterioles, causing it to constrict

up resistance, down bloodflow

Down Pgc, GFP, GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Tubuloglomerular Feedback

A

macula densa senses fluid flow and releases paracrines that act on the afferent arteriole

up fluid flow, =contraction of afferent arteriole=down GFR

down Pgc, GFP, GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Mesangial Cell Contraction

A

contract in response to stretching, decreasing the SA for filtration

constriction of the glomerular capillary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

When does Extrinsic Control of GFR take over?

A

acute, SEVERE changes in blood volume,

GFR is reduced, conserving water

1) baroreceptor Reflex on
2) MAP=CO*TPR=down MAP=upCO, upTPR
3) fluid is conserved, conserved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Clinical Applications of GFR…

A

Filtered Load,
Clearance,
Measuring Renal Plasma Flow,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

FIltered Load

A

How much of a particular solute is filtered per unit time

freely cross the gomerular membrane

E=F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

clearance

A

E=F

x is freely filtered and not secreted or reabsorbed, then CLEARANCE X=GFR

EX) INULIN!!!!!

40
Q

how do you determine GFR from a substance?

A

INULIN YOU BITCH

41
Q

Measuring Renal Plasma FLow

A

PAH is FREELY FILTERED and is NOT REABSORBED

any PAH that does not get filtered is completely SECRETED

PAH=RENAL PLASMA FLOW (RPF)

E=F+S

42
Q

dU/dt=

A

urine production rate/flow

43
Q

Creatinine

A

freely filtered, only secreted in small amounts

clearance of creatinine gives GFR

44
Q

Reabsorption

A

takes place in proximal and distal tubules of the nephron

45
Q

What are the main barriers to movement in Reabsorption?

A

Apical and Basolateral Membranes of the tubular epithelium

46
Q

What are the three types of reabsorption from filtrate back to blood?

A

1) Active Solute Transport
2) Passive Water Movement
3) Passive Solute movement

47
Q

Active solute transport

A

transporters can be on the apical or basolateral membrane

48
Q

Passive Water Movement

A

transport of things increases plasma osmolarity so water follows

salt goes in, water follows

49
Q

Passive Solute Movement

A

tubular concentration of solute Z is higher so it moves to the plasma (often following water)

without help, using only open channels (hence passive)

50
Q

How much water and salt reabsorption happen in the PROXIMAL TUBULE?

A

70%

51
Q

____ is key for the movement of solutes into the kidney

A

Na+

52
Q

Much of the energy used for the kidneys is for the _________ pump

A

sodium potassium pump

constantly limits na

and the reason why the kidney uses so much ATP

53
Q

when the kidney’s capacity to reabsorb is exceeded, what happens?

A

EXCRETION!

54
Q

GLUCOSE

A

Freely filtered,
NEVER SECRETED

E=F-R

55
Q

Tm

A

Transport Maximum

when all transporters for a substance are taken

56
Q

Renal Threshold

A

the plasma concentration at which the solute shows up in Urine

57
Q

Diabetes Mellitus

A

‘sweet siphon’

due to not enough Type I or Type II secretion to insulin, GLUCOSE IS NOT MOVED OUT OF THE BLOOD

FL of glucose> Tm of gluose

excess gluose is excreted in urine

58
Q

Secretion

A

from peritubular capillaries and vasa recta (blood) into tubular lumen (filtrate)

59
Q

Fluid Balance

A

1) most of your body water comes in through food/drink
2) most of you body water is peed out
3) normally, fluid in=fluid out

60
Q

Hypovolemia

A

decreased plasma volume and results when water loss exceeds water gain

LOOSING MORE WATER THAN GAINING

61
Q

Hypervolemia

A

increased plasma volume and results when water gain exceeds water loss

TOO MUCH WATER

62
Q

Hyper and Hypo volemia and have what consequences?

A

directly affects MAP
change osmolarity of the cells in the body

63
Q

How do your kidneys maintain water balance?

A

by changing the concentration of urine through antidiuresis and diuresis

64
Q

antidiuresis:

A

if there is TOO LITTLE water in the plasma, SAVE WATER (CONCENTRATED URINE)

65
Q

DIURESIS

A

TOO MUCH WATER

DILUTE URINE (GET RID OF WATER)

66
Q

How do your kidneys change urine concentratoin?

A

by changing the permeability of the collecting duct.

any by altering the number of aquaporins (water pores_

67
Q

Osmolarity increases ________ _______ ___ __ ________ creating a
strong gradient for driving water
from the filtrate (lumen of the
kidney) to the extracellular space.

A

from the cortex to the medulla

68
Q

If the collecting duct membrane is permeable, what does water do?

A

water flows out of the filtrate concentrating the urine (antidiuresis)

69
Q

lots of aquaporins……

what happens to water?

A

means that urine concentrated and water flows out

70
Q

few aquaporins…..

what happens to water>?

A

water flows in, and urine is diluted

71
Q

How do you change the number of aquaporins?

A

Vasopressin (ADH)

binds to g-protein leading to insertion of aquaporin 2 channels in the apical membrane

72
Q

How do you change the permeability of the collecting
duct

A

by regulating vasopressin

73
Q

Low circulating ADH = _______ _______ = reduced permeability
= diuresis = _____ ______ = removal of excess water

A

fewer aquaporins

dilute urine

74
Q

High circulating ADH = more aquaporins = ________ ________
= antidiuresis = concentrated urine = water saved

A

increased permeability

75
Q

More vasopressin (ADH) =

A

= more water conservation

76
Q

How is vasopressin (ADH) regulated?

A

The hypothalamic neurons projecting to the posterior pituitary
secrete more vasopressin (ADH) in response to:

77
Q

The hypothalamic neurons projecting to the posterior pituitary
secrete more vasopressin (ADH) in response to:

A

up osmolarity in hypothalamus

down MAP and Blood Volume

78
Q

Any reduction in plasma volume (hypovolemia)
triggers…….

A

vasopressin release and water
conservation

ex) excessive sweating, diarrhea, hemorrhage

79
Q

Diabetes insipidous

A

‘tasteless’

excessive urin production and thirst

4 types

80
Q

Neurogenic:

A

defect in the pituitary or hypothalamus – little
production of ADH

excessive urine

81
Q

Nehprogenic

A

defect in the kidney’s response to ADH (could be
due to mutation in ADH receptor or mutation in aquaporin 2).

broken ADH suppresor

82
Q

Dipsogenic

A

damagic to hypothalamic thirst center

take in too much water

83
Q

Gestational

A

overproduction of vasopressinase by mom

vpinase breaks down VP excessively

84
Q

normovolemia

A

water in=water out

85
Q

How does your body maintain Na+
homeostasis?

A

…by regulating reabsorption

86
Q

Is na+ freely filter?

A

Na+ is freely filtered at the glomerulus and it is not secreted

87
Q

How is Na+ reabsorbed?

A

Na+ reabsorption differs slightly in the proximal and distal tubules:

But the general pattern is the same

sodium potassium pump, na moves out

na from tubular fluid moves down its concentration gradient into cell

88
Q

How is Na+ reabsorption regulated?

A

by aldosterone
up sodiuim potassiuim pumps in apical and basolateral membranes

89
Q

Increased aldosterone has
two effects on the late distal
tubules and collecting ducts:

A

1) up sodium potassium channels in apical membrane

2) stimulates synthesis of sodium potassiuim pumps in basolateral membrane

90
Q

more aldosterone =

A

more Na+ reabsorption and more K+ secretion

91
Q

How is aldosterone regulated?

A

1) cells of the Macula Densa release a paracrine signal in
response to low Na+ in the distal
tubule (this indicates low fluid flow
or low blood pressure)

2)This signal triggers granular
cells of the juxtaglomerular
apparatus to release renin

92
Q

increased renin =

A

increased aldosterone

93
Q

How does renin increase circulating aldosterone?

A
  1. Liver secretes Angiotensinogen
  2. Juxtaglomerular cells secrete renin which cleaves Angiotensinogen to
    Angiotensin I
  3. Capillary endothelial cells secrete Angiotensin-converting enzyme (ACE),
    which cleaves Angiotensin I to Angiotensin II.
  4. Angiotensin II stimulates adrenal cortex to secrete aldosterone.
94
Q

K+

A

reabsorbed and secreted in nephron

regulated by secretin in late distal tubules and collecting duct

Aldosterone has opposite effects on Na+ and K+

95
Q

increased aldosterone =

A

more Na+ reabsorption
more K+ secretion

Physiology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions