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Flashcards in chapter 18 Deck (60):
1

where are cardiac centers in the brain located?

medulla oblongata

2

What is an electrocardiogram?

a composite of all the action potentials generated by nodal and contractile cells at a given time

3

what is a P wave caused by?

depolarization of SA node

4

what causes a T wave?

ventricular repolarization

5

what occurs during the first sound of a heart beat?

AV valves close and signifies beginning of systole

6

what occurs during the second sound of a heart beat?

SL valves close at the beginning of ventricular diastole

7

What is End-systolic volume (ESV)?

Volume of blood remaining in each ventricle after the ejection phase

8

What are murmurs?

abnormal heart sounds

9

What is end-diastolic volume?

Volume of blood in a ventricle at the end of a filling cycle

10

Which ECG wave would appear after the 2nd sound?

T wave

11

What is SV or stroke volume?

Volume of blood pumped out by a ventricle with each beat

12

what is the cardiac output?

Volume of blood pumped by each ventricle in one minute

13

what is the cardiac reserve?

difference between resting and maximal Cardiac Output

14

what is preload in relation to heart physiology?

the degree of stretch of cardiac muscle cells during diastole

15

what do positive inotropic agents do to stroke volume and contractility?

they increase both

16

what is afterload in regards to cardiac physiology?

the pressure that must be overcome for ventricles to eject blood

17

Mitral stenosis would have what effect on the preload and stroke volume of the left ventricle?

decrease preload and stroke volume

18

positive chronotropic factors

increase heart rate

19

negative chronotropic factors

decrease heart rate

20

Another word for the Atrial reflex

Bainbridge reflex

21

what is an Atrial reflex?

Sympathetic reflex initiated by increased venous return that increases the heart rate

22

effect of epinephrine on heart rate?

increases it

23

effect of thyroxine on heart rate?

increases heart rate and enhances the effects of norepinephrine and epinephrine

24

abnormally fast heart rate

Tachycardia

25

abnormally slow heart rate

Bradycardia

26

what is the physiological pacemaker of the heart?

the sinoatrial node (SA node)

27

another word for unstable potential

pacemaker potential or prepotential

28

what is the sinus rhythm?

the rhythm of the contraction of the heart set by the SA node

29

how many action potential (heart beats) dones the SA node produce per minute?

90-95

30

how many action potentials does the AV node produce per minute?

40-60

31

The only electrical connection between the atria and the ventricles

the atrioventricular bundle or
bundle of His

32

final leg of the intrinsic conduction system of the heart

Purkinje fibers

33

irregular heart beat

arrhythmia

34

the 2 cardiac centers in the medulla oblongata

cardioacceletory center
cardioinhibitory center

35

stenosis

when a valve does not close properly

36

regurgitation

when a valve does not open properly

37

best point to listen for the aortic valve

second intercoastal space to the right of the sternum

38

best point to listen for the pulmonary valve

second intercoastal space to the left of the sternum

39

best point to listen for the mitral valve

fifth intercoastal space to the left of the sternum

40

best point to listen for the tricuspid valve

fifth intercoastal space the right of the sternum

41

what is contraction of the heart called?

systole

42

what is relaxation of the heart called?

diastole

43

factors the reduce contractility of cardiac muscles

negative inotropic

44

the phase of the cardiac cycle when all 4 heart valves are closed again and no blood flows into or out of the ventricles

isovolumetric relaxation

45

where the bundle of His is located

interventricular septum

46

when atrial repolarization occurs as seen on an EKG

QRS complex

47

The entire ventricular myocardium is depolarized during this time on an EKG

S-T segment

48

directly supplies the papillary muscles with nerve impulses

Purkinje fibers.

49

what are the lub-dup heart sounds heard during auscultation of the heart associated with?

the heart valves closing

50

what is blood flow during ventricular filling most dependent on?

pressure changes

51

stimulation of this nerve reduces heart rate

vagus nerve

52

this electrical event causes contraction of the atria

p wave

53

3 factors that affect the size of the stroke volume

preload
contractility
Afterload

54

what are factors that increase heart rate called?

positive chronotropic

55

effect of parasympathetic nervous system on heart rate

slows heart rate

56

effect that the sympathetic nervous system has on heart rate

positive chronotropic and inotropic

57

what the heart exhibits at rest

vagal tone

58

where is the first lub heard

at isovolumetric contraction

59

what is isovolumetric contraction?

the phase when both the AV and SL valves are both closed

60

the short-lived drop in aortic pressure when SL valves close

dicrotic notch