Lab #7 information

Question 1

what is the cardiac cycle?

Answer 1

intricately orchestrated progression of events in which pacemakers initiate/coordinate contractile cell activity

Question 2

which comes first? electrical or mechanical events?

Answer 2

electrical

Question 3

what are the electrical events of the heart

Answer 3

depolarization and repolarization of the heart

Question 4

what is used to measure electrical events of the heart

Answer 4

ECG

Question 5

where does the depolarization begin? (ES Step 1)

Answer 5

sinoatrial node where autorythymic cells in the R atrium are the pacemaker of the heart

Question 6

EC steps

Answer 6

1. SA node depolarizes
2. Electrical activity goes rapidly to AV node via internodal pathways
3. Depolarization spreads more SLOWLY across atria. Conduction slows through AV nodes
4. Depolarization moves rapidly through ventricular conducting system to the apex of the heart
5. depolarization waves spreads upward from the apex

Question 7

conducting system of the heart (EC location pathway)

Answer 7

SA Node > internodal pathways > AV node > AV bundle > Bundle branches > Purkinkje fibers

Question 8

what are purkinje fibers

Answer 8

specialized conducting cells of the ventricles

Question 9

why is it necessary to direct electrical signals?

Answer 9

the blood is pumped out of the ventricles through the top of the atria chambers

Question 10

What is the letters listed with ECG?

Answer 10

PQRST

Question 11

P wave is

Answer 11

atrial depolarization

Question 12

PQ or PR segment

Answer 12

conduction through AV node and AV bundle (atria contract)

Question 13

R wave

Answer 13

atrial repolarization

Question 14

ST segment

Answer 14

ventricles contract

Question 15

T wave

Answer 15

ventricular repolarization

Question 16

what are the two phases of the cardiac cycle

Answer 16

contraction (systole)
relaxation (diastole)

Question 17

What are the steps of the cardiac/mechanical cycle

Answer 17

1 Late diastole
2. Atrial systole
3. Isovolumic ventricular contraction
4. Ventricular ejection
5. Isovolumic ventricular relaxation

Question 18

Late diastole

Answer 18

when both sets of chambers relaxed and ventricles fill passively

Question 19

atrial systole

Answer 19

atrial contraction forces a small amount of additional blood into ventricles

Question 20

isovolumic ventricular contractions

Answer 20

first phase of ventircular contraction pushes AV valves closed but doesn’t have enough pressure to open semilunar valves

Question 21

Ventricular ejection fraction

Answer 21

as ventricular pressures rises and exceeds pressure in the arteries, teh semilunar valves open and blood is ejected

Question 22

What phases have ventricular diastole

Answer 22

5, 1, 2

Question 23

Ventricular systole number

Answer 23

3, 4

Question 24

Atrial diastole numbers

Answer 24

3, 4, 5, 1

Question 25

atrial systole numbers

Answer 25

2

Question 26

what does EDV stand for

Answer 26

end diastolic volume

Question 27

what reflex primarily maintains blood pressure homeostasis (mean arterial blood pressure)

Answer 27

baroreceptors

Question 28

what types of sensory receptors are the baroreceptors

Answer 28

stretch sensitive mechanoreceptors called barocepectors

Question 29

baroreceptors job and location

Answer 29

L: walls of the carotid arteries and aorta J: monitor the pressure of the blood flowing to the brain (carotid baroreceptors) and to the body (aortic baroreceptors)

Question 30

which afferent nerve carry sensory info regarding blood pressure to the brain?

Answer 30

vagus and glossopharyngeal

Question 31

which part of the brain is the integrating center for the baroreceptor

Answer 31

cardiovascular control center in medulla oblongata

Question 32

two general efferents from the CVCC

Answer 32

sympathetic (less NE released) parasympathetic (more acetylcholine on muscarinic receptor)

Question 33

what is the vagus nerve

Answer 33

the primary parasympathetic efferent

Question 34

the parasymp efferent is upregulated when BP

Answer 34

is HIGH

Question 35

what is the primary cardiovascular target of the vagus nerve?

Answer 35

SA Node

Question 36

what is the effect of the vagus nerve on HR?

Answer 36

decreases HR

Question 37

the three cardiac nerves are all ___ efferents to the heart

Answer 37

sympathetic

Question 38

Where do the 3 cardiac nerves synapse on the heart?

Answer 38

SA node, ventricular myocardium, BV (arterioles and veins)

Question 39

when BP is high the sympathetic efferent is ____

Answer 39

downregulated

Question 40

when blood pressure is low, the sympathetic efferent is

Answer 40

high

Question 41

what are the three effects of excitation of the sympathetic efferent

Answer 41

1. Vasodilation 2. decreased force of contraction 3. decreased heart rate 2/3 - both lead to dec cardiac output 1 - leads to decreased peripheral resistance

Question 42

what does the oculo cardiac reflex

Answer 42

lowers heart rate elicited by pressure to the eyes

Question 43

cold stress to various body parts ___ ___ response

Answer 43

increases sympathetic response, increasing HR and Pressure

Question 44

what is the valsalva maneuver

Answer 44

procedure with multiphasic effect on BP and heart rate * any menueyver that increases INTRATHORACIC pressure

Question 45

how can you describe the Valsalva maneuver

Answer 45

1. immediate effects of pushing blood out of thorax/pulmonary circulation into the arteries - what is the effect on BP and the compensatory effect on HR? 2. effects of pressure in teh chest compressing the vena cava and reducing venous return - what is the effect on BP and the effect on HR

Question 46

Valsalva phases

Answer 46

1. systolic BP inc, pulse dec 2. systolic BP dec, pulse inc *intersect* 3. systolic BP super low, pulse higher 4. original

Question 47

flow chart of blood flow through the heart and the cardiovascular system

Answer 47

etc.

Question 48

what is the function of the heart valves

Answer 48

to prevent backward flow of blood

Question 49

function of papillary muscles

Answer 49

controls the valves in the hear by closing open valves in the heart

Question 50

which valve is affected when the left posteromedial papillary muscle is damaged

Answer 50

mitral valve

Question 51

valvular prolase

Answer 51

when papillary muscles cannot maintain valve closure

Question 52

consequences of mitral valves prolapse

Answer 52

a decreasing pulse, heart failure, decrease of stroke volume, decrease of cardiac output

Question 53

how does the change in cardiac pressure affect MAP

Answer 53

lowers the map, because when more blood is leaving the heart than coming, the MAP decreases

Question 54

how to calculate MAP

Answer 54

Diastolic BP + 1/3 (systolic - diastolic_

Question 55

flow chart of map

Answer 55

notes

Question 56

what is the effect of left ventricular failure on pulmonary circulation and pressure

Answer 56

causes pulmonary conjestion due to the failure of the left ventricle

Question 57

does the change in pulmonary blood pressure increase or decrease capillary filtration int the lungs

Answer 57

increase, because there is an increase in pulmonary blood presssure

Question 58

what is conestive heart failure

Answer 58

progressive condition where the heart msucle is too weak to pump blood causing blood to back up and conjuestion

Question 59

what affect should left ventricular failure have on capillary filtration in the kidneys

Answer 59

cause the capilarry filatrion to shut down/stop working completely because of lack of blood to kidneys