Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BMSC 208 > Renal 1 > Flashcards

Renal 1 Flashcards

Renal Lectures 1-4

1
Q

6 Kidney Functions

A
  1. Regulation of ECF volume and bp
  2. Regulation of osmolarity: kidneys + behaviour
  3. Maintenance of ion balance: Na+, K+. and Ca+2
  4. Homeostatic regulation of pH
  5. Excretion of wastes: metabolic and xenobiotics
  6. Production of hormones: erythropoietin, renin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

direction of filtration flow

A

blood to kidney

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

direction of reabsorption flow

A

kidney to blood

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

direction of secretion

A

blood to kidney

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

direction of excretion flow

A

collecting duct out

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

order tubular components

A

bowman’s capsule, proximal tubule, descending limb of loop of henle, ascending loop of henle, distal tubule, collecting duct

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

how much L of plasma is filtered at the glomeruli each day? % reabsorbed? L excreted?

A

180L filtered
over 99% reabsorbed
1.5L excreted

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

% of reabsorption occurring in the proximal tubule

A

70%

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

determine amount (mL) filtered/day from CO = 5L/min

A

CO = 5L/min
kindeys receive about 20% of CO (1L/min)
60% of blood is plasma (0.6L/min)
20% of plasma is filtered into Bowman’s capsule (0.12L/min)

0.12L/min x 60min/hr x 24 hours/day
= 173 (180L) plasma filtered/day
= 125 mL/min

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

triple filtration barrier exists of:

A
  1. capillary endothelial cells -fenestrated (small pores, fluid and dissolved solutes)
  2. basal lamina -extracellular matrix (protein mesh, keeps proteins and blood cells in)
  3. podocyte end feet (proteins, filter)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does mesangial cells influence filtration

A

by influencing the SA of the capillary available for exchange with lumen of Bowman’s capsule

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

3 pressures that regulate filtration from glomerular capillaries into renal tubules

A
  1. hydrostatic pressure of blood in the glomerular capillaries favours filtration
  2. colloid osmotic (oncotic) pressure (pi) of blood is the pressure gradient due to the presence of plasma proteins and opposes filtration
  3. Bowman’s capsule hydrostatic pressure (fluid pressure) opposes filtration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

GFR definition and normal rate

A

volume of fluid that filters from glomerular cappilaries into the Bowman’s capsules per unit time

normally: 125mL/min or 180L/day

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

two factors that influence GFR

A
  1. filtration pressure
  2. filtration coefficient
    a. slit surface area
    b. filtration barrier permeability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

T or F: GFR is relatively constant

A

T bc autoregulated when arterial bp is between 80 and 180

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

how is GFR regulated

A

primarily regulated by renal arterioles (afferent and efferent) through resistance

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

what happens to GFR when afferent arteriole is constricted

A

Vasoconstricting afferent arteriole = decreased Renal Blood Flow = decreased GFR = decreases capillary bp

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

what happens to GFR when efferent arteriole is constricted

A

vasoconstricting efferent arteriole = decreased renal blood flow = increased hydrostatic pressure = increased GFR

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

what happens to GFR when afferent arteriole resistance is decreased/arteriole dilates

A

afferent arteriole vasodilate = renal blood flow increases = hydrostatic pressure increase = GFR increase

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

what happens to GFR when efferent arteriole dilates

A

EA dilate= RBF increase, decrease GFR, decrease volume and pressure

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

2 autoregulatory mechanisms that maintain GFR when bp changes

A
  1. Myogenic response of afferent arterioles
  2. tubuloglomerular feedback
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is myogenic response

A

afferent arteriole contraction in response to vascular smooth muscle (depolarization of Ca+2 channels)

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

what is tubuloglomerular feedback

A

local control pathway in which fluid flow through the tubule portion of the nephron influences GFR

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

steps of tubuloglomerular feedback

A
  1. GFR increases
  2. flow through tubule increase
  3. flow past MACULA DENSA cells increases
  4. PARACRINE FROM MACULA DENSA TO AFFERENT ARTERIOLE (maybe ATP converted to adenosine)
  5. afferent arteriole CONSTRICTS
  6. resistance in afferent arteriole increases
  7. hydrostatic pressure in glomerulus decreases
  8. GFR decreases

Increase NaCl transport in macula densa cells/increased cilia movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what nervous system can influence GFR
sympathetic neurons
26
what does sympathetic nervous system do to regulate GFR
override local control by changing resistance or coefficient neurons release norepinephrine that acts on alpha 1 adrenergic receptors on both afferent and efferent arterioles leading to vasoconstriction
27
what hormones influence GFR?
angiotensin 2 (constrictors) prostaglandins (dilate) alter filtration coefficient by acting on podocytes and/or mesangial cells modulation of podocytes changes size of filtration slits = alter permeability contraction of mesangial cells alters capillary SA available for filtration
28
amount excreted = ? - ? +?
excreted = filtered - reabsorbed + secreted
29
reabsorption transport types
1. transepithelial (transcellular) transport 2. paracellular transport can be active or passive
30
how is Na+ transported from tubule lumen to ECF primary What process is this a part of
basolateral Na+ transport is always active via Na-K-ATPase - Na enters cell down its gradient at apical membrane - Na pumped out BLM by Na/K ATPase (Na out, K in then out via leak channel) reabsorption
31
how is Na+ transported from tubule lumen to ECF secondary
secondary active transport: symport with Na+ -Na+ moves down gradient and uses SGLT protein to pull glucose into cell against it's conc gradient (both into cell at same time = symport) - glucose diffuses out of the BLM using GLUT protein - Na+ pumped out via Na/K ATPase
32
how is urea reabsorbed
passive diffusion
33
endocytosis in reabsorption is mediated by?
receptor mediated endocytosis - receptor binding plasma proteins known as megalin - digested by lysosomes in cell for very small plasma proteins or peptides
34
explain transport rate at saturation, glucose, diabetes
renal transport can reach saturation where all the transporters are occupied - glucose is completely reabsorbed in the proximal tubule - the transport maximum is the transport rate at saturation - excess glucose filtered = more glucose than there are transporters and some glucose is excreted (diabetes)
35
what is renal threshold
plasma conc of a solute when it begins to appear in the urine- occurs at transport maximum
36
glucosuria or glycosuria?
glucose in urine occurs with elevated blood glucose rare genetic disorder with reduces transporters
37
peritubular capillary pressures favour ? explain pressure changing throughout peritubular capillaries and flow of fluid and solutes
reabsorption glomerulus= Hydrostatic = 55 colloid osmotic= 30 fluid pressure = 15 favour filtration of blood to tubule down pressure gradient then: hydrostatic pressure of capillaries = 10 bc fluid moved out of blood colloid osmotic = 30 bc plasma proteins don't filter out difference is 20 mmHg, so pressure gradient favours reabsorption back down pressure gradient from tubule to capillaries
38
define secretion
transfer of molecules from ECF to lumen of nephron, mainly depends on membrane transport proteins
38
secretion controls homeostatic regulation of what ? where?
K+ and H+ distal organic compound removal (meds, food additives in proximal region)
39
secretion enhances the ___ of a substance
excretion
39
is secretion active or passive
active, move substances against conc gradient
39
what is OAT
organic anion transporters tertiary active transport process
40
explain the OAT pathway
interstitial fluid to blm membrane to cell to tubule lumen (secretion) 1. direct active transport: NaK ATPase keeps intracellular Na conc low 2. Secondary indirect active transport: Na-Dicarboxylate cotransporter concentrates a dicarboxylate inside cell using energy stored in Na gradient **Alpha-ketoglutarate** 3. Tertiary indirect active transport: BLM OAT1-3 concentrate organic anions inside cell using energy stored in the dicarboxylate gradient 4. Organic anions enter the lumen on exchange for a dicarboxylate (on apical membrane)
40
40
explain how OAT pathway solved penicillin being in high demand but excreted every 3-4 hours
penicillin given with competitor probenecid which is preferred by OAT transporter so the probenecid was excreted faster than penicillin
40
how to measure excretion (2 ways)
1. solute clearance 2. creatine clearance
41
clearance equation
clearance of X = excretion rate of X (mg/min) / conc X in plasma (mg/mL plasma = mL/min
42
substance most freely filtered and not reabsorbed or secreted
inulin- polysaccharide found in plants
43
creatine for clearance
freely filtered by glomerulus but secreted very smally, slight overestimate plasma creatine conc of 0.01mg/mL and excretion rate of 1.25mg/min (urine samples over 24 hours) = 125mL/min = GFR
43
net renal handling
kidney handle any filtered solute by measuring solutes plasma conc and excretion rate compare filtered load to its excretion rate OR compare GFR to clearance
44
net reabsorption
less of a substance appears in urine than was filtered
45
net secretion
more appears in urine than was filtered
45
renal clearance is a non-invasive method using collected urine and a blood sample to:
1. calculate GFR: if you can find a substance that is filtered, not reabsorbed and not secreted. Filtered load = excreted load 2. understand the net renal handling of any filtered solute
46
glucose is completely?
reabsorbed, amount filtered = amount reabsorbed
47
Urea clearance is an example of?
net reabsorption, 50% reabsorbed, 50% excreted
48
penicillin clearance is an example of
net secretion, some secreted, none reabsorbed = more penicillin excreted than filtered GFR= 100mL/min, clearance = 150mL/min, clearance greater than GFR
49
micturition reflex
full bladder activates stretch receptors undergo rhythmic contractions (pacemaker cells)
50
what is smooth muscle of bladder called
detrusor muscle
51
micturition reflex: relaxation of internal sphincter innervated by ?
decrease sympathetic
52
micturition reflex: relaxation of external sphincter innervated by ?
decrease somatic motor neuron activity
53
micturition reflex: what innervated contraction of detrusor muscle
increased parasympathetic neuron activity, neurons fire to contract bladder wall
54
what is incontinence? causes?
inability to control urination voluntarily - infants: corticospinal connections necessary for voluntary control are not established yet - damage to internal or external sphincters -aging: loss of muscle tone, stroke, Alzheimer's, CNS problems, prostate growth in males

BMSC 208 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions