Urinary System Flashcards
(70 cards)
1
Q
The 5 Functions of urinary system
A
- regulation of water and inorganic balance
- excretion of metabolic waste products
- elimination of some foreign chemicals
- Glucogenesis
- production of hormones and enzymes
2
Q
Four main parts of the kidney
A
renal capsule
renal cortex
renal medulla
ureter
3
Q
Ureter
A
tube leading from kidney
4
Q
types of nephron and where they are located
A
cortical nephron: renal cortex
juxtamedullary nephron: renal medulla
5
Q
nephron functions
A
- filtration of material from blood to lumen
- secretion of material from blood to lumen
- reabsorption of material from lumen to blood
- excretion of materials from lumen to external environment
6
Q
What’s the importance of renal corpuscle
A
solids and fluds move through it from the glomerulus to Bowman’s capsule to be filtered from the blood to lumen
7
Q
Filtration: Insulin
A
completely filtered no reabsorption
8
Q
Filtration: glucose
A
somewhat filtered and completely reabsorbed
9
Q
Filtration: Penicillin
A
somewhat filtered, more secreted, none reabsorbed
10
Q
Filtration: Urea
A
somewhat filtered and half is reabsorbed, 50% excreted
11
Q
Calculate total amount excreted
A
amount filtered-amount reabsorbed+amount secreted=amount excreted
12
Q
Major constituents of filtrate
A
- water
- sodium
- glucose
- urea
13
Q
Flow of fluid in the nephron
A
- bowman’s space -> Proximal tube -> loop of Hnele-> distal convoluted tubule -> collecting duct system
14
Q
fenestra
A
small holes in glomerlular capillaries that facilitate fluid transport from capillaries into filtration slits of podocytes
15
Q
Juxtaglomerular apparatus function
A
regulates function of each nephron
16
Q
Where does blood enter the glomerulus
A
afferent arterioles
17
Q
Where does blood exit the glomerulus
A
efferent arterioles
18
Q
macula densa cells function
A
detects NaCl levels in distal tubule and secrete vasoconstrictors afferent arterioles -> ecrease GFR
19
Q
how does filtration increase
A
vasodilation of afferent arteriole
vasoconstriction of efferent arteriole
20
Q
Find net glomerular filtration pressure
A
GFP = glomerular capillary blood pressure-bowman’s space pressure - osmotic pressure
21
Q
Factors that increase Glomerular capillary blood pressure
A
- increase in renal arterial pressure
- decrease in afferent arteriole resistance via vasodilation
- increase in efferent arteriole resistance via faso constriction
22
Q
Factors that increase bowman’s space pressure
A
- increase in intralobular pressure because of obstruction of tubule or extrarenal urinary pathways
23
Q
factors that increase osmotic pressure
A
- increase amount of protein
- increase in osmotic pressure of systemic circulation
- decrease in renal plasma flow
24
Q
Calculation of glomerular filtration rate
A
filtration coefficient * GFP
25
factors that increase filtration coefficient
1. decrease in molecule size
2. increase in electrical charge (become more positive)
3. increase in glomerular surface area
26
how does renin affect blood pressure, outline the angiotensin-renin process
1. Renin converts angiotensinogen into angiotensin I
2. angiotensin-converting enzyme converts angiotensin I into angiontensin Ii
3. angiotensin II causes an increase in blood pressure (increases renal blood flow and filtration)
27
angiotensin II effects
INCREASE BLOOD PRESSURE
vasoconstriction in cardiovascular system
increases salt and H2O retention in kidney
produces aldosterone in adrenal cortex
28
which cells secrete renin
juxtaglomerular cells
29
luminal section of plasma membrane
faces the filtrate in the tubular lumen
30
basolateral section
faces the peritublar capillary
31
Outline the movement of Na+ from tubule lumen into proximal tubule cell
1. diffusion through a sodium channel
2. cotransport with organic molecules
3. counter transport with hydrogen ions
32
outline the transport of Na+ from proximal tubule cell into interstitial fluid
active transport: Na+ into interstitial fluid - K+ into tubular cells via NaK ATPase
33
Effects of Sodium transport into interstitial fluid
1. Na+ reabsorbed into bloodstream
2. whatever transported with it gets reabsorbed also
3. K+ enters urine
4. water enters urine
34
renal threshold
concentration of solute in plasma at the maximum transport rate
35
Loop of Henle process: Thin descending limb
water diffuses out, highly permeable to water
36
Loop of Henle process: Thick ascending limb
Na-K-2Cl symporter pumps Na+, K+, and 2 Cl- out of tubuar lumen
K+: recycled back in through K+ channels
37
Loop of Henle process: Thin ascending limb
permeable to NaCl, impermeable to water
38
Purpose of counter-current multiplier system and where
objective to build a gradient
using energy
In loop of henle
39
Purpose of counter-current osmotic exchanger and where
no energy
diffusion preserves gradient
In Vasa recta
40
what determines ability to concentrate urine
relative thickness of renal medulla
41
hormonal response to dehydration: vasopressin
1. vasopressin, ADH, creates a falcutative response( opens up water channels in collecting duct and osmolarity of urine increase
42
hormonal response to dehydration: aldosterone
creates obligatory response: increase Na/K+ ATPase activity -> reabsorption of Na+ increases -> water reabsorption follows
43
what determines transit time in a nephron
salt reabsorption
| water reabsorption
44
effect of urea in nephron
contributes to high osmolarity in medulla
45
Renal autoregulation: myogenic response
if blood pressure drops or increases -> arterioles dilate or constrict-> allowsGFR to be constant over range of blood pressure
46
Renal autoregulation: tubuloglomerular feedback
increased flow of filtrate sensed by macula dense -> it signals afferent arterioles to constrict
might use inulin to estimate rate
47
Problems if GFR too high
1. fluid flows through tubules to rapidly to be reabsorbed
| more pee-> dehydration
48
Problems if GFR too low
tubules reabsorb wastes that should be eliminated
| Asotemia: high levels of Na in blood
49
Regulate GFR (sympathetic system)
release norepinephrine epinephrine, or stimulates renin-angiotensin mechanism - vasoconstriction
blood shunted away from kidneys
50
what stimulates the release of renin
1. direct sympathetic enervation
2. intra-renal barorecptors
3. macula dense cells sense sodium
51
what is atrial natriuretic peptide
ANP is secreted when blood volume increase stretches atria
1. promotes vasodilation-> increase in GFR
2. inhibits sodium reabsorption
3. inhibits aldosterone
52
natiuresis
increased levels of sodium in urine
53
aldosterone
increases sodium reabsorption when there is too much potassium
54
Parathormone
regulates Ca2+ when decrease in Ca2+ plasma concentration
55
what is sweating caused by
decrease plasma volume, bp -> increase in plasma osmolarity -> fluid pulled from intracellular fluid
56
What are the consequences of sweating
1. decrease GFR
| 2. increase aldosterone, vasopressin, angiotensin II
57
Thirst is promoted by
1. decrease in plasma volume and blood pressure-> increase angiotensin II levels
2. increase in plasma osmolarity-> trigger osmoreceptors
3. dry mouth and throat
58
thirst inhibited by
metering of water intake by GI tract
59
response to acidosis
glutamine cotransported with Na+ ion tubule cell and broken down into bicarbonate which acts as a buffer
60
acute renal failure
ability of kidneys to excrete wastes and regulate blood volume, pH and electrolytes is impaired
61
glomerulonephritis
inflammation of glomeruli
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renal insufficiency
nephrons have been decreased due to disease
63
uremia
high plasma urea levels
64
hemodialysis
patiens' blood passed through dialysis machine which separates molecules on ability to diffuse through selectively permeable membrane-> urea and wastes removed
to help renal insufficiency
65
peristalsis
moves urine through ureters from renal elvis to urinary bladder
66
trigone
region ureters enter bladder through
67
urine movement
1. hydrostatic pressure forces urine through nephrons
2. peristalsis moves urine through ureters from renal pelvis to urinary bladder
3. ureters enter bladder obliquely through region called trigone
68
neuron control
1. Stretch receptors detect filling of bladder-> afferent signals to spinal cord
2. Signals sent back via parasympathetic fibers via pelvic nerve (from S2 and
S3 spinal cord segments)
3. Efferent signals excite detrusor muscle
4. Involuntary control: Efferent signals relax internal urethral sphincter
(involuntary unless inhibited by brain)
5. Voluntary control: Micturition center in pons receives signals from stretch
receptors
6. Time to urinate: pons returns signals to spinal interneurons that
excite detrusor and relax internal urethral sphincter -> urine voided
7. Not time to urinate: pons returns signals to spinal interneurons
that keep external urehtral sphincter contracted -> urine retained
8. Time now: signals from pons cease and external sphinter
relaxes->urine voided
69
micturition reflex
Filling bladder stimulates stretch receptors ->parasympathetic fibers
inhibit contraction of external urethral sphincter and stimulate contraction
of detrusor muscle
70
diuretics
Mechanism: increase GFR and decrease tubular reabsorption
o Effect: increase urine output, decrease blood volume
o Purpose: for hypertension and congestive heart failure
