Phys1 Cardiovascular System

Front 1

location, size, and surround structure of heart

Back 1

middle of the thoracic cavity
weighs a little more than 1/2 lb.
majority of the heart lies on the left side of the thoracic cavity

Front 2

chambers and valves of heart

Back 2

2 atria, 2 ventricle
AV valves:
1. tricuspid valve
2. mitral valve
Semilunar valves:
1. aortic valve
2. pulmonary valve

Front 3

coronary arteries

Back 3

heart receives blood for own nourishment;
coronary arteries on either side of aorta just after the blood leaves the left ventricle ( enters coronary arteries AFTER other blood flows past; diastole)

Front 4

the anatomical structure of cardiac conduction system

Back 4

SA node
AV node
bundle of his
R & L bundle branches
purkinje fibers

Front 5

SA Node

Back 5

pacemaker of heart ( in R atrium)
depolarizes 70-100 times/min.
action potential produced b/c of leaky NA channels > stimulates atria to contract = known as sinus rhythm
-innervated by the ANS ; sympathetic tone, parasympathetic tone (slightly greater)

Front 6

AV node

Back 6

slight delay b/t SA and AV node to allow ventricles to fill with blood
-depolarizes as a result of the SA node depolarizing the atrial myocardium
if SA node isn't working can take over and dep. 40-50/min. (nodal rhythm)

Front 7

Bundle of His

Back 7

AV bundle> branches into R and L bundle branches

Front 8

R and L bundle branches

Back 8

receives stimulus from bundle of his

Front 9

purkinje fibers

Back 9

along the bundle branches; when stimulus reaches fibers it sends a wave of dep. through the ventricles beginning at the apex and progressing toward the semilunar valves ; to push blood up and out

Front 10

autorhythmicity

Back 10

heart does not require outside nerves to stimulate contraction ; comes from cardiac conduction system

Front 11

EDV

Back 11

end diastolic volume; the volume of blood in the ventricle at the end of diastole

Front 12

ESV

Back 12

end systolic volume; the volume of blood in the ventricle after systole

Front 13

cardiac output

Back 13

volume of blood pumped from the heart per minute
Q=HR x SV

Front 14

stroke volume

Back 14

volume of blood pumped per beat of the heart
SV=EDV-ESV

Front 15

factors that regulate cardiac output

Back 15

heart rate and stroke volume

Front 16

how pressure influences flow of a fluid

Back 16

pressure flows DOWN a concentration gradient

Front 17

pressure changes created to allow blood flow through chambers of heart

Back 17

inverse relationship b/t pressure and volume
inc. volume = dec. pressure
dec. volume = inc. pressure

when chambers contract volume decreases

Front 18

1. cardiac cycle
ventricular filling

Back 18

1. when the atria fills with the blood the pressure increases
2. ventricles are relaxing at same time (vol. inc. and pressure dec. )
3. when pressure is > in atria than vent. both AV valves open (70%) of blood flows
4. SA depolarizes causing atria contraction (remaining 30% flows)

Front 19

2. cardiac cycle
isovolumetric contraction

Back 19

1. ventricles are filled with blood and signal arrives to purkinje fibers (dep. of ven= contraction)

Front 20

3. cardiac cycle
ventricular ejection

Back 20

1. pressure inc. because of inc. blood volume and dec. volume of ventricle
2. blood forced through semilunar valves

Front 21

4. cardiac cycle
isovolumic relaxation

Back 21

1. after previous ventricular contraction
vent. volume inc. pressure dec.
2. atria start to fill with blood
-all valves are closed

Front 22

heart sounds

Back 22

1. lub: AV valves closing
2. dub: semilunar valves closing

Front 23

how is HR modified to inc. or dec. cardiac output

Back 23

by mechano, chemo, or thermal receptors
they detect changes in temp, pH, CO2, O2, and movement in muscles> then goes to cardiovascular center which sends out the signal to the effectors that increase or decrease HR appropriately, which inc. or dec.'s cardiac output

Front 24

regulation of cardiac output

Back 24

regulated by heart rate and stroke volume

Front 25

regulation of HR and cardiac output

Back 25

in the brain the cardiovascular center controls HR through the ANS innervation to SA node

parasympathetic slows heart rate (vagus nerve signals to SA and AV nodes)
sympathetic increases heart rate (accelerator nerves signal to SA, AV, and myocardium)

Front 26

regulation of SV and its relationship to Q

Back 26

Frank Starling law , EDV, and venous return, contractility and afterload
-EDV is determined by venous return

Front 27

Venous return

Back 27

1. venoconstriction>inc. pressure>inc. flow>inc. EDV>inc. stroke volume
2. skeletal muscle pump
3. respiratory pump

Front 28

contractility

Back 28

the amount of force produced by the contracting myocardium at a given preload
caused by negative (decrease cont.) and positive ( inc. cont.) ionotropic agents

Front 29

afterload

Back 29

resistance from blood pressure in the major arteries that DECREASES stroke volume - opposes the opening of the valves and limits stroke volume

Front 30

intercalated discs

Back 30

allow adjoining cells to interlock which cause cells to increase contact area
-provide strength and prevent pulling apart when the heart contracts
- provide channels that allow ionis to flow from one cell directly into the next

Front 31

coronary blood flow

Back 31

5% of circulating blood supplies themyocardium to meet it's own metabolic needs
-coronary arteries stem from the aorta just after blood leaves L ventricle

Front 32

cardiac cycle

Back 32

events involved during the course of one heart beat that account for blood flow through the heart
-blood moves through the heart as a result of pressure changes in the chambers

Front 33

components of blood (2)

Back 33

1. plasma
2. formed elements
-red blood cells, platelets, white blood cells

Front 34

functions of blood

Back 34

1. transport (O2, CO2, nutrients, wastes, hormones, heat)
2. protection (clotting, immunities)
3. regulation (fluid, balance, pH)

Front 35

primary function of red blood cells

Back 35

transport gases between lungs and the tissues of the body

Front 36

reasons for pulsatile blood flow

Back 36

prevent the BP from falling during relaxation, when blood is not leaving the heart
-the walls of the vessels are elastic and provide force for blood to move on recoil