cardiovascular control

Question 1

what equation relates mean arterial pressure, cardiac output and total peripheral resistance

Answer 1

MAP=COxTPR

Question 2

what is the MAP=COxTPR equation derived from?

Answer 2

the hemodynamic equation flow = pressure/resistance

or pressure=flow*resistance

Question 3

how can cardiac output be calculated?

Answer 3

heart rate x stroke volume

Question 4

what does diastolic pressure depend on?

Answer 4

the degree of dilation of constriction of the arteries

Question 5

what does systolic pressure depend on?

Answer 5

peripheral resistance (diastolic pressure) AND cardiac output because it is the diastolic pressure plus the pressure derived from the cardiac output

Question 6

how is pulse pressure calculated?

Answer 6

pulse pressure=systolic pressure-diastolic pressure

Question 7

what is pulse pressure influenced by?

Answer 7

mainly cardiac output, but also elasticity of arteries and total peripheral resistance

Question 8

what is minute to minute blood pressure mostly regulated by?

Answer 8

the autonomic nervous system

Question 9

what does the sympathetic nervous system do to the cardiovascular system?

Answer 9

increases cardiac output, increases total peripheral resistance thus increasing blood pressure and blood flwo to skeletal muscle beds

Question 10

what does the parasympathetic system do to the cardiovascular system?

Answer 10

decreases cardiac output, decreases total peripheral resistance, decreases blood flow to skeletal muscles; stimulates rest and digest response

Question 11

what does acetylcholine bind to on the heart?

Answer 11

muscarinic receptors

Question 12

what adrenergic receptors are present on the heart and what do they bind?

Answer 12

B1 receptors and they bind epinephrine and norepinephrine

Question 13

what adrenergic receptors are present on most arterioles and what do they bind?

Answer 13

alpha1 receptors and they bind epinephrine and norepinephrine

Question 14

what adrenergic receptors are present in skeletal muscle beds and what do they bind?

Answer 14

beta2 and they bind mostly epinephrine

Question 15

what do mild stimulations of the sympathetic system cause?

Answer 15

release of mainly norepinephrine

Question 16

what do major stimulations of the sympathetic nervous system cause?

Answer 16

release of norepinephrine and epinephrine

Question 17

is there parasympathetic innervation to arterioles?

Answer 17

no

Question 18

are the muscarinic receptors at the arterioles? what are the implications?

Answer 18

yes. even though there are receptors there is no innervation so physiological effects can be different than pharmacological effects

Question 19

does the baroreceptor reflex function in conjunction or in opposition to drug injections?

Answer 19

the baroreceptor functions to control perturbations in blood pressure mainly by controlling heart function so if the heart is producing an opposite response than expected following drug injections it is likely due to baroreceptor action

Question 20

what are the receptors in the ganglia?

Answer 20

nicotinic; respond to acetylcholine; stimulation of post-ganglionic nerves in both parasympathetic and sympathetic nervous systems; net effect of acetylcholine is increased blood pressure

Question 21

what is the baroreceptor reflex?

Answer 21

in response to stretch detected in the baroreceptors in the carotids and aortic arch, baroreceptor primarily decreases cardiac output in order to lower blood pressure

Question 22

what is the pathway of the baroreceptor reflex

Answer 22

neural signals from the baroreceptor are sent to the nucleus tracturs solaris in the brainstem via vagal afferents (and glossopharyngeal?) and cause vagal efferents to release acetylcholine on heart that decreases cardiac output; there is also a much smaller effect on sympathetic tone but this is minor

Question 23

what occurs when there is decreased stretch detected in the baroreceptors?

Answer 23

vagal afferent firing slows and vagal tone on heart decreases and suppression of sympathetic firing decreases; sympathetic stimulation also raises blood pressure and cardiac output

Question 24

where are the baroreceptors located?

Answer 24

in the aortic arch and in the carotid sinus

Question 25

what is intra-arterial/direct blood pressure monitoring?

Answer 25

it is when a blood pressure catheter is inserted into the artery of an animal; generally the catheter tip is fluid filled and connected to a pressure transducer peripheral to the animal via fluid-filled tubing
another more expensive technology is a solid state pressure sensor inserted directly into the artery (millar catheter)