Lecture 13 - Cardiovascular Control System

Question 1

Factors increasing renin release from kidney?

Answer 1

SNS, decreased blood flow to kidney, macula densa chloride concentration

Question 2

Effects of Angiotensin II?

Answer 2

increase SNS, tubular Na and Cl reabsorption and K excretion, promote aldosterone secretion, arteriolar constriction (increase BP), promote ADH secretion from PPG

Question 3

Systemic arterial baroreceptors?

Answer 3

stretch sensitive ion channels, highly populated in carotid sinus and aortic arch, sense stretch of arterial wall and intra-lumenal pressure

Question 4

Characteristics of carotid sinus baroreceptors?

Answer 4

a pressure threshold required to alter nerve firing rate, also a maximum which firing no longer increases, and rate sensitivity i.e. for a given pressure the rate of firing is greater in pulsatile pressure than for steady pressure

Question 5

When arterial pressure drops:?

Answer 5

increased heart rate and cardiac inotropic state, constriction of precapillary vessels in skeletal, splanchic, cutaneous and renal circulations (not coronary or cerebral), venoconstriction, increased catecholamine secretion from adrenal medulla, and increased circulating levels of ADH, AgII and other hormones

Question 6

Cardiac receptors?

Answer 6

decrease renal sympathetic stimulation; increased volume means slower filtration rate to increase water excretion

Question 7

Osmoreceptors?

Answer 7

in hypothalamus, sense changes in effective plasma osmolality by altering volume, decreasing/increasing ADH release to increase/decrease water excretion

Question 8

Peripheral chemoreceptors?

Answer 8

increased discharge when PaO2 decreases, increasing sympathetic innervation of heart and vessels; homeostatic function where decreased arterial pressure supplies less oxygen, therefore vasoconstriction activated to restore blood pressure

Question 9

Higher central nervous systems?

Answer 9

wtf