block b lecture 2

Question 1

5 main functions of cardiovascular system

Answer 1

-rapid transport of nutrients
-removal of waste products of metabolism
-hormonal control by transporting hormones
-temp regulation
-host defense

Question 2

the walls of the heart are composed of cardiac muscle cells, what is this

Answer 2

myocardium

Question 3

what is the inner surface of walls that is in contact with the blood

Answer 3

endocardium

Question 4

what is the inner lining of the pericardium is continuous with the covering of the heart itself

Answer 4

epicardium

Question 5

what is the fluid filled membranous sac in which the heart is located

Answer 5

pericardium

Question 6

what are the 2 phases of the cardiac cycle

Answer 6

systole
diastole

Question 7

what is the name of the contractile phase

Answer 7

systole

Question 8

what is the name of the relaxation, filling phase

Answer 8

diastole

Question 9

what are cardiac muscle cells joined together by

Answer 9

gap junctions

Question 10

what do gap junctions allow for the spread of

Answer 10

excitation from one cell to another

Question 11

myocardium contains specialized cells that constitute what system

Answer 11

conducting system

Question 12

what supplies the myocardium with blood

Answer 12

coronary arteries

Question 13

summary of events leading to cardiac contraction

Answer 13

-depolarization
-opening of voltage ca2 channels
-flow of ca2
-ca2 release
-rise in ca2 conc
-contraction

Question 14

5 structures that are important to spread electrical activity

Answer 14

-sino-atrial node =pacemaker
-atrial myocardium
-atrioventricular node (tactical pause)
-ventricular conducting fibres (freeways)
-ventricular myocardium (surface roads)

Question 15

what is an action potential (cardiac)

Answer 15

transient depolarisation of cell membrane

Question 16

where does cardiac action potential occur

Answer 16

in nodal cells

Question 17

how is cardiac action potential transmitted

Answer 17

from adjacent myocytes through gap junctions

Question 18

2 cell types of the intrinsic conduction system

Answer 18

fast depolarising
slow depolarising

Question 19

what does ARP stand for

Answer 19

absolute refractory period

Question 20

what does RRP stand for

Answer 20

relative refractory period

Question 21

ARP in myocytes

Answer 21

250ms

Question 22

at rest what predominates (para or sympathetic)

Answer 22

parasympathetic

Question 23

what are sympathetic fibres receptors

Answer 23

noradrenaline -b1 receptors

Question 24

what do noradrenaline b1 receptors increase permeability of

Answer 24

nodal cell plasma membrane to Na and Ca2

Question 25

what are parasympathetic fibre receptors

Answer 25

acetylcholine M2 receptors

Question 26

what do acetylcholine -M2 receptors increase permeability to

Answer 26

K and decrease Na and Ca2

Question 27

how do you calculate cardiac output

Answer 27

SV x HR

Question 28

what is stroke volume (SV)

Answer 28

volume of blood pumped per contraction

Question 29

what is end diastolic volume (EDV)

Answer 29

volume of blood in ventricle before contraction

Question 30

what is the Frank Starling law of the heart

Answer 30

represents the relationship between stroke volume and end diastolic volume

Question 31

names of some of the other receptors in the heart

Answer 31

b1 receptor, mostly muscarinic M2 b2 a1 receptors angiotensin II

Question 32

what is arterial blood pressure given by

Answer 32

cardiac output (CO) x total peripheral resistance (TPR)

Question 33

what does total peripheral vascular resistance depend on (TPR)

Answer 33

blood viscosity arteriolar radius

Question 34

healthy young adult arterial bp and TPR

Answer 34

120/80 mmHg

Question 35

what does noreadrenaline a1 (sympathetic nerves) do to arteriolar radius

Answer 35

constrict

Question 36

what does nerves, acetylcholine, and M3 (sympathetic cholinergic) do to arteriolar radius

Answer 36

dilate

Question 37

what does b2 (plasma adrenaline) do to arteriolar radius

Answer 37

dilate

Question 38

what does decreased PO2 and increased PCO2, K, and adenosine do to arteriolar radius

Answer 38

dilate

Question 39

intermediate reflexes of regulation of arterial blood pressure

Answer 39

baroreceptor reflex chemoreceptor reflexes