urinary 3

Question 1

RAA

Answer 1

renin-angiotensin-aldosterone system

Question 2

angiotensin

Answer 2

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

Question 3

angiotensin 1

Answer 3

proteins that acts as a precurser molecule for angiotensin 2

Question 4

angiotensin 2

Answer 4

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

Question 5

renin

Answer 5

enzyme that helps control your BP

Question 6

release of renin triggers

Answer 6

cascade of activations resulting in angiotensin 2

Question 7

how renin is secreted

Answer 7

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

Question 8

aldosterone

Answer 8

balances the levels of sodium and potassium

Question 9

detection of plasma volume

Answer 9

baroreceptors/stretch

Question 10

detection of 0

Answer 10

osmoreceptors

Question 11

ANP atrial natriuretic peptide

Answer 11

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

Question 12

plasma volume - osmolarity

Answer 12

decreased PV - Incresed O
increased PV- decreased O

Question 13

osmolarity

Answer 13

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

Question 14

ANP secretion leads to

Answer 14

• 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

Question 15

vasopressin/ antidiuretic

Answer 15

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

Question 16

hormonal regulation- vasopressin

Answer 16

• 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)

Question 17

concentrated urine

Answer 17

• 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)

Question 18

dilute urine

Answer 18

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

Question 19

vasopressin -aquaporin channels

Answer 19

• 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

Question 20

inhibiting vasopressin

Answer 20

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

Question 21

facultative water reabsorption

Answer 21

• 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

Question 22

sweat

Answer 22

• 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

Question 23

thirst -water appetite

Answer 23

• 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

Question 24

hyponatremia

Answer 24

• 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

Question 25

movement from kidney to urinary bladder

Answer 25

via **Ureter** _-smooth muscle contraction_ **_(peristalsis_**_), hydrostatic pressure, gravity_ contribute to **movement to urinary bladder** **-**once passed renal tubules = _urinary excretion_ (filtered +secreted - reabsorbed)

Question 26

urinary bladder

Answer 26

storage till voiding

Question 27

urethra

Answer 27

exit passage to external environment

Question 28

urinary bladder - filling

Answer 28

- 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

Question 29

muscle - innervation during filling

Answer 29

**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)**

Question 30

urinary bladder - micturition reflex

Answer 30

- micturition reflex signal comes back - involuntary : **detrusor→** _contract_ **both sphincters**→ _relax_ → **voiding/micturition**

Question 31

voluntary control

Answer 31

- 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_