Ans Physiology And Pharmacology The Cardiovascular System

Front 1

the autonomic nervous system affects the cardiovascular system in what four way

Back 1

chronotropic effect (heart rate), inotropic effect (cardiac contractility), arterial vascular resistance, venous tone (venous capacitance)

Front 2

define chronotropic effect

Back 2

heart rate

Front 3

define inotropic effect

Back 3

cardiac contractility

Front 4

define venous tone

Back 4

venous capacitance/storage

Front 5

what is the key role of the autonomic nervous system on the cardiovascular function

Back 5

stay at normal arterial blood pressure

Front 6

define autonomic reflexes

Back 6

changes in the ANS activity that occur in response to changes in blood pressure

Front 7

in the CV system, where is the parasympathetic innervation

Back 7

the vagus nerve synapse with postganglionic parasympathetic nerves in the wall of atria, interatrial septum near sinoatrial node and atrioventricular nod and on coronary arteries. NOT ventricles.

Front 8

true or false, PANS innervate the ventricules to decrease contractility

Back 8

False. there is no PANS innervation in the ventricles so not affect contractility.

Front 9

for PANS, what receptors and what g protein used?

Back 9

PANS in heart use M2 muscarinic receptor. The GI protein reduces heart rate and increase PR interval

Front 10

SA and AV nodes have what kind of PANS receptor

Back 10

M2 and use GI pathway

Front 11

what three effects does the receptor activated in PANS play on action potential of pacemakers

Back 11

PANS use M2 in GI pathway. 1-increaes the IK current so more K so membrane more negative (phase 4). 2- reduce IF (funny Na channels) so less Na ready so slow depolarization. 3-decrease slow inward calcium current ICa that usually make upstroke of action potential in pahse 0 so slower action potential.

Front 12

what effect to PANS receptors have on atrial muscle contractility

Back 12

M2 receptor in GI pathway. decreases atrial muscle contractility by decreasing inward calcium current and decreasing CAMP production.

Front 13

how do PANS and SANS oppose each other at the g protein level

Back 13

PANS is GI and M2 receptor. SANS is GS using cAMP method and beta receptor. GI stops adenylyl cyclase so no cAMP.

Front 14

how do the receptors for PANS behave like heteroreceptors

Back 14

the M2 receptors also expressed in postganglionic SANS nerves to inhibit norepinephrine release. so M2 binds Ach to inhibit NE. similar to role of alpha 2 found at PREganglionic nerve.

Front 15

define heteroreceptor

Back 15

a receptor that is activated by a neurotransmitter that is not the neurotransmitter that spews out of the synapse.

Front 16

how do the receptors for PANS act like autoreceptors

Back 16

M2 receptors located on postganglionic PANS nerves bind Ach to inhibit Ach

Front 17

where are M3 receptors

Back 17

M3 receptors are on endothelial cells of vessels.

Front 18

what is the role of M3 receptors? what g protein function?

Back 18

M3 receptors in endothelial cells of walls of vessels. Make nitric oxide synthase for NO. use GQ pathway making phospholipase C-IP3-calmodulin pathway.

Front 19

define endothelium derived relaxing factor

Back 19

nitric oxide from M3 receptors on walls of vessels

Front 20

how does nitric oxide function in the cell

Back 20

makes cGMP that dephosphorylate myosin light chain kinase and so muscle relaxes.

Front 21

what nerves innervate the M3 receptors

Back 21

None.

Front 22

how does atropine work in heart

Back 22

atropine increases heart rate by stopping PANS normal tone.

Front 23

what happens in synaptic bulb of SANS nerve? synthesis, storage, clearance?

Back 23

amino acid tyrosine makes dopamine, norepi and epinephrine. vesicular monoamine tranporter take the neurotransmitter to synaptic vesicles like a shuttle. cleared by reuptake, recycled by monoamine oxidase in mitochondria, recycled by catecholamine-o-methyltransferase in synaptic gap.

Front 24

what organ also has lots of monoamine oxidase

Back 24

liver. to chew up things that could potentially act like sympathetic stimulant.

Front 25

give examples of substances that inhibit reuptake of SANS neurotransmitters

Back 25

serotonin-selective reuptake inhibitor antidepresants and cocaine.

Front 26

what are the autoreceptors for SANS

Back 26

alpha 2 located on PREganglionic SANS nerves to stop norepinephrine release

Front 27

what is the function of alpha receptors on smooth muscle

Back 27

constrict/contract. ALWAYS

Front 28

what is effect of beta 2 receptors on smooth muscle

Back 28

dilate ALL smooth muscle EXCEPT in the heart

Front 29

for heart, what function of:
beta 1
beta 2

Back 29

beta 1 and beta 2 increase heart rate and contractility

Front 30

in vessels what function of alpha

Back 30

vasoconstrict

Front 31

in vessels what function of beta 2

Back 31

vasodilate ALWAYS ESCEPT for cardiac muscle vessels

Front 32

what three effects does the receptor activated in SANS play on action potential of pacemakers

Back 32

beta receptors for SANS. increase slow inward calcium current pase 0 upstroke of action potential so that increase heart rate. 2-increase the IF current (funny sodium channel) making more negative so that can have depolarization in phase 4. 3-sequester Ca faster so shorten action potential length and refractory period

Front 33

how does SANS increase contractility

Back 33

increase the Ca influx. increase sequesteration for faster relaxation and ready to contract again.

Front 34

how does constriction work for vessels when have SANS activation

Back 34

alpha receptors simulated by SANS so vasoconstrit. reduce diameter increase resistance. increase afterload and BP.

Front 35

why does SANS constrict and also dilate

Back 35

SANS constrict and dilate vessels to make optimal redistribution of blood to organs

Front 36

describe how SANS in charge of dilation

Back 36

to optimally redistribute blood to organs. beta 2 vasodilate vessels when get epinephrine from adrenal medulla.

Front 37

what receptors activated:
epinephrine
norepinephrine

Back 37

epinephrine alpha 1=alpha2 and beta 1=beta 2.
norepinephrine alpha1=alpha2
ONLY beta 1

Front 38

what is postural hypotension and how occur?

Back 38

no vascular response to SANS activation. patient taking drugs to block alpha constrictors. syncope

Front 39

what is role of hormones in maintaining blood pressure

Back 39

baroreceptors in juxtoglomerular apparatus of kidney sense low blood pressure and make renin and eventually aldosterone.

Front 40

describe pathway to aldosterone

Back 40

baroreceptors in juxtoglomerular apparatus of kidney tell cells make renin, angiotensin, angiotensin I, angiotensin II, aldosterone from adrenal cortex.

Front 41

what is functionof aldosterone

Back 41

when low blood pressure, aldosterone stops excretion of water to maintain blood volume.

Front 42

what happen when inject Ach?

Back 42

Ach is PANS so normall slow heart rate. IV Ach increase heart rate reflex response uninnervated M3 in vessels release nitric oxide relaxers. baroreceptors kick in and turn on SANS

Front 43

what happen when inject norepinephrine

Back 43

norepinephrine is SANS normal effect increase heart rate. IV norepinephrine debrease heart rate. when NE bind alpha increases BP B1 increase contractility. baroreceptors kick in and turn on PANS.