the heart - mech events of the cardiac cycle

Question 1

how is cardiac muscle connected

Answer 1

through intercalated disks with Gap junctions

Question 2

how is the AP of skeletal muscle different from cardiac

Answer 2

skeletal have a shorter AP

Skeletal can do tetanus

Question 3

what happens during the plateau phase of cardiac muscle AP

Answer 3

trigger Ca enters the cells

Question 4

what is the roll of the HEart

Answer 4

The pump that moves the blood

Question 5

how is cardiac activity expressed

Answer 5

Cardiac output (amount of blood moved per unit time)

Question 6

what is the average cardiac output

Answer 6

5 liters a minute

Question 7

what caues the first heart sound

Answer 7

Closure of the AV valves

Question 8

what causes the second heart sound

Answer 8

closure of the Aortic and pulmonary valves

Question 9

what is stenosis

Answer 9

Narrowing

Question 10

what is regurgitation

Answer 10

insufficiency (leaky)

Question 11

what causes murmurs

Answer 11

stenosis
regurgitation
septal defects

Question 12

when do you hear stensosi

Answer 12

When valves are open

Question 13

when do you hear regurgitation

Answer 13

When valves are closed

Question 14

how are the system and pulmonary circulations plumbed

Answer 14

in series

Question 15

how are organs in systemic circulation plumbed

Answer 15

Parallel

Question 16

what is systole

Answer 16

Ventricle contraction

Question 17

what is diastole

Answer 17

Ventricles relaxed

Question 18

what causes the valves of the heart to open

Answer 18

Pressure differences on both sides of the heart

Question 19

how much filling is passive is ventricle

Answer 19

80%

Question 20

what does the final portion of filling of the ventricles

Answer 20

Artrial kick

Question 21

what happens in isovolumetric contraction

Answer 21

both valves closed (aortic pressure is higher than the ventricle)
raising of ventricular contraction

Question 22

how do you know something is isovolumic contraction

Answer 22

both valves closed

volume is non-changing

Question 23

when does QRS happen relative to ventricular contraction

Answer 23

QRS preceeds ventricular contraction

Question 24

what is the eq for cardiac output

Answer 24

Heart ratexStroke volume

Question 25

what pumps more blood, the Right or Left heart

Answer 25

pump both the same amount

Question 26

what pumps higher pressure, Right or left heart

Answer 26

Left heart is higher pressure

Question 27

what does parasympa and sympa affect in the heart

Answer 27

Parasympa closes funny channels | Sympa opens funny channels

Question 28

how can hormones affect the heart

Answer 28

release of Epinephrine leads to an increase in HR

Question 29

how can one speed up heart rate

Answer 29

deliver more sympa hormone (epinephrine) more sympa neurotransmitter (norepinephrine) decrease release of parasympa neuro (acetylcholine)

Question 30

can parasympa change stroke volume

Answer 30

No

Question 31

what are the three factors influencing stroke volume

Answer 31

Preload Sympa input to the ventricles Afterload

Question 32

what is preload

Answer 32

The volume of blood in the ventricles just before contraction - end diastolic volume

Question 33

what is afterload

Answer 33

the pressure against which the ventricle epumps

Question 34

why does preload increase stroke volume

Answer 34

increased stretch of ventricle aligns actin and myosin to a more optimal pattern of overlap

Question 35

how to further increase stroke volume beyond preload

Answer 35

preload+ sympa signals

Question 36

how does sympa signals lead to higher stroke volume

Answer 36

causes ventricles to relax more rapidly - more time to refill causes ventricles to contract more rapidly

Question 37

what does sympa do inside the mycardial cell to increase stroke volume

Answer 37

Regulates/increases Ca

Question 38

what is the frank-starling mechanism

Answer 38

increased preload leads to increased stroke volume

Question 39

does preload change the amount of inracellular ca

Answer 39

no`

Question 40

can you increase stroke volume and increase heart rate separately

Answer 40

No, not under normal circumstances

Question 41

how can one measure cardiac function

Answer 41

``` Thermodilution cardiac output Angiography Echocardiogram MRI ejection fraction ```

Question 42

what is ejection fraction

Answer 42

Measure of contractility

Question 43

what is the formula for ejection fraction

Answer 43

(End diastolic volume-end systolic volume)/ End diastolic volume

Question 44

what is hypertrophic cardiomyopathy

Answer 44

increased heart wall thickness myocardial disarray - specifically interfer with blood ejection

Question 45

what are the symptoms of hypertrophic cardiomyopathy

Answer 45

Angina Arrhythmias Sudden cardiac death