urinary 3 Flashcards

1
Q

RAA

A

renin-angiotensin-aldosterone system

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

angiotensin

A

inactive plasma protein, not doing anything because theres no renin in the blood stream
-becomes angiotensin 1

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

angiotensin 1

A

proteins that acts as a precurser molecule for angiotensin 2

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

angiotensin 2

A

protein that acts directly on blood vessels for constriction and raising blood pressure

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

renin

A

enzyme that helps control your BP

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

release of renin triggers

A

cascade of activations resulting in angiotensin 2

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

how renin is secreted

A

many pathways but all start with decreased plasma volume (carries water, salts, enzymes)

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

aldosterone

A

balances the levels of sodium and potassium

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

detection of plasma volume

A

baroreceptors/stretch

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

detection of 0

A

osmoreceptors

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

ANP atrial natriuretic peptide

A

small peptide secreted by the heart when there is atrial stretch or high systemic blood pressure

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

plasma volume - osmolarity

A

decreased PV - Incresed O
increased PV- decreased O

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

osmolarity

A

the concentration of a solution expressed as the total number of solute particles per litre

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

ANP secretion leads to

A
  • increased sodium excretion
  • will increase urine output as water follows sodium, decreasing blood volume via plasma volume

-more filtration and secretion

  • can also decrease the release of vasopressin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

vasopressin/ antidiuretic

A

regulates blood pressure and increases reabsorption of water from the kidneys. conserving body water and defending against dehydration

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

hormonal regulation- vasopressin

A
  • both volume and concentration of urine output are variables
  • excess h20 ingested leads to →decrease vasopressin secretion and → increased H20 excretion (diluted urine)
  • decreased plasma volume leads to → increased vasopressin secretion→decreased H20 excretion (concentrated urine)
17
Q

concentrated urine

A
  • vasopressin high, greater water reabsorption, excretion low volume concentrated urine
  • associated with dehydration because vasopressin will try and absorb as much water as possible (19.8% water reabsorbed)
18
Q

dilute urine

A
  • vasopressin low, collecting duct relatively impermeable to water ; excretion high volume dilute urine
  • diuresis : elevated urine flow rate (diuretic - substance that cause increase urine)
19
Q

vasopressin -aquaporin channels

A
  • number of aquaporin water channels variable in latter part of tubules
  • mostly in distal tubule and collecting duct

-presence of aquaporins virtually absent in collecting ducts unless vasopressin present

-vasopressin causes insertion of aquaporins on apical membrane

20
Q

inhibiting vasopressin

A
  • caffeine, alcohol inhibit secretion of vasopressin
  • Diabetes insipidus : failure to synthesize, release or respond to vasopressin (can reach urine output of 25L/day)
21
Q

facultative water reabsorption

A
  • adapting to need
  • normal hydration - 19% water reabsorbed
  • dehydration -19.8% water reabsorbed; increase number of aquaporins (APQ)
  • overhydration - as low as 0% water reabsorbed; decrease number of aquaporins
22
Q

sweat

A
  • loss of both electrolytes (like sodium) and water
  • salt appetite : hedonistic and regulatory (humans little regulatory)
  • severe sweating will lead to increased plasma aldosterone →which lowers Na+ secretion

and

-increased vasopressin which will lead to → decreased H2O excretion

23
Q

thirst -water appetite

A
  • kidney minimizes losses but really need ingestion to replace losses
  • stimulating thirst centre in hypothalamus is key
  • thirst a subjective feeling stimulated by several paths (plasma osmolarity most important) → increased plasma osmolarity detected by →osmoreceptors→signal thirst

-receptors for thirst similar to vasopressin secretion

-also psychological and conditioned responses for thurst

24
Q

hyponatremia

A
  • problem with large losses of both electrolytes and water, but only replacing the water
  • hyponatremia involves decreased Na+ concentration of interstitial fluid and plasma
  • leads to decreased osmolarity of interstitial fluid and plasma
  • leads to osmosis of water from interstitial fluid into intracellular fluid
  • leads to water intoxication or hypotonic solution (cells swell)
  • endurance performance - consuming large amounts of plain water, minor levels give mental confusion and dizziness
25
Q

movement from kidney to urinary bladder

A

via Ureter

-smooth muscle contraction (peristalsis), hydrostatic pressure, gravity contribute to movement to urinary bladder

-once passed renal tubules = urinary excretion (filtered +secreted - reabsorbed)

26
Q

urinary bladder

A

storage till voiding

27
Q

urethra

A

exit passage to external environment

28
Q

urinary bladder - filling

A
  • distensible sac with a capacity ~ 700-800 mL where urine is stored prior to voiding/micturition
  • At a certain point filling triggers sensation of fullness (~ 200-400 mL) and signal sent to spinal cord (initiating micturition reflex a spinal reflex)
  • conscious awareness of desire to urinate before micturition reflex
29
Q

muscle - innervation

during filling

A

detrusor (smooth muscle) → innervated by Parasympathetic inhibited (relax)

internal urethral sphincter (smooth muscle) → sympathetic stimulated (contract)

external urethral sphincter (skeletal muscle) → innervated by somatic motor stimulated (contract)

30
Q

urinary bladder - micturition reflex

A
  • micturition reflex signal comes back
  • involuntary :

detrusor→ contract

both sphinctersrelaxvoiding/micturition

31
Q

voluntary control

A
  • learn to initiate and stop micturition
  • external urethral sphincter control (maintain stimulation and contraction)
  • signal from cerebral cortex can over ride for limited period of time