CVS control

Question 1

what causes renin release

Answer 1

1. increase sympathetic stimulation
2. decrease P in afferent arteriole
3. decrease macula densa NaCl delivery

Question 2

actions of angiotensin 2

Answer 2

• arteriolar vasoconstriction
• increase aldosterone
• increase proximal tubule Na+ reabsorption
• increase sympathetic activity
• increase ADH release

Question 3

osmoreceptors

Answer 3

• in hypothalamus
• sense changes in effective plasma osmolality by altering volume
• changes synthesis & release of ADH by post. pituitary

Question 4

peripheral chemoreceptors

Answer 4

• in carotid sinus (carotid body), aortic arch (aortic body)
• increased firing from low PaO2
• stimulating increase RR, increase sympathetic drive to heart, vessels
• chemoreceptors are hyperactive in some hypertensive patients
  (baseline PaO2 normal)

Question 5

extrinsic factors of the cardiovascular control system

Answer 5

neural

• PNS
• SNS

endocrine

• Adr
• RAAS
• ADH
• NP

Question 6

cardiac receptors

Answer 6

• vagal afferents sense change in cardiac volume

- linear increase in nerve activity with left atrial P

Question 7

response to increased BV

Answer 7

• increase HR
• decreased renal sympathetic stimulation (increased diuresis)
• also change ADH secretion by projection to hypothalamus

Question 8

systemic arterial baroreceptors

Answer 8

• mainly in carotid sinus, aortic bodies
• sense changes in pressure
• rapid resolution to homeostasis

Question 9

arterial baroreflex

Answer 9

afferents = carotid sinus nerve & aortic depressor nerves

efferents = sympathetic & vagal nerves

in hypertension, baroreflex is not as responsive

Question 10

baroreflex in BP drop

Answer 10

• increase HR, inotropic state
• increase constriction of pre-capillary resistant vessels (not cerebral or coronary)
• venoconstriction
• increased catecholamine release (adrenal medulla)
• increase ADH, angiotensin 2

Question 11

arterial baroreflex pathway

Answer 11

• baroreceptor inputs -> NTS -> PVN:
  
  • > post. pituitary -> modulation of ADH secretion
  • > RVLM -> sympathetc drive to vessels