Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

EKG Midterm > 1 Intro and Electrophysiology > Flashcards

1 Intro and Electrophysiology Flashcards

1
Q

What is the pericardial sac?

A

The tough fibrous sac that encloses the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the layers of the pericardial sac?

A

Parietal pericardium (outer)

Visceral pericardium (inner)

Pericardial fluid in between, lubricating the two layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three layers of the heart wall?

A

Epicardium - thin serous membrane on outer aspect of the heart

Myocardium - the muscular middle layer

Endocardium - thin serous membrane lining the inner chambers and valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two basic cell types in the heart?

A

Myocardial cells - have contractile ability

Conducting cells - pacemaker cells and electrical conducting cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the myocardial cells

A

“Working cells” of the heart

Consist of latticework of protein filaments (myosin and actin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The branching network of myocardial cells in the heart is called…

A

A syncytium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cardiomyocytes are ________ cells with a ______ nucleus, surrounded by a membrane called a _________.

A

Branching

Central

Sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Special contact points where myocardial cells connect

A

Intercalated disks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

_________ in the intercalated disks permit rapid conduction of electrical impulses from one cell to the next

A

Gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Myocytes all contract together as a single unit with stimulated, thanks to _______ which hold the cells together during contraction

A

Desmosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The right and left atria are separated by…

A

The interatrial septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The right and left ventricles are separated by …

A

The interventricular septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the four valves of the heart?

A

Mitral
Tricuspid
Pulmonary
Aortic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What controls the mitral and tricuspid valves?

A

Papillary muscles and chordae tendineae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the plate of fibrous connective tissue between the atria and ventricles do?

A

Provides a support structure for the AV and semilunar valves

Separates the upper pumping chambers from the lower chambers

Electrically insulates the atria from the ventricles - electrical impulses in the atria must travel through specific conduction pathways to get to the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Systole is the _______ phase and diastole is the _______ phase

A

Contraction

Relaxation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The amount of blood ejected from the ventricles during systole

A

Stroke volume

Usually 60-100cc of blood during each systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the formula for cardiac output?

A

Heart Rate x Stroke Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Stretching force on the ventricular muscle at end diastole

A

Preload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The pressure against which the heart must pump (ie blood pressure in the aorta)

A

Afterload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Formula for blood pressure

A

Cardiac Output x Peripheral Vascular Resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is the heart regulated?

A

By the brain, via the autonomic nervous system

Hormones of the endocrine system

Heart tissue itself

Receptors monitor adequacy of cardiac output (located in blood vessels, kidneys, brain, heart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

______ detect changes in pressure in the heart and main arteries (aorta and carotid)

A

Baroreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

______ detect changes in the chemical composition of the blood

A

Chemoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Info from baro- and chemoreceptors is transmitted to the ________ in the ________.

A

Cardioregulatory center

Medulla oblongata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sympathetic Nervous System causes release of _____ and _____ from ________

A

NE and Epi

Adrenal gland

(Why it’s also called the “adrenergic system”)

27
Q

Effects of the Sympathetic NS on the heart

A

Fight or flight response

Speeds heart, increases myocardial excitability

Acts as “cardioaccelerator” - increased pacemaker firing, increased impulse conduction through heart, increased force of contraction, coronary vasodilation

28
Q

In the parasympathetic nervous system, the ________ stimulates the release of ________.

A

Vagus nerve

Acetylcholine

The “cholinergic system”

29
Q

Effects of the parasympathetic NS on the heart

A

Slows heart and slows electrical conduction

“Cardioinhibitor” - decreased rate of SA node pacemaker, decreased rate of conduction through AV node

30
Q

What happens when BP is too low?

A

The cardioregulatory center activates the SYMPATHETIC NS —> NE/Epi release —> Inc HR/contractility, vasoconstriction —> Inc CO and BP

31
Q

What happens when BP is too high?

A

The cardioregulatory center activates the PARASYMPATHETIC NS —> release of ACh —> Dec HR and lower BP

32
Q

What are the key properties of myocardial cells?

A

Automaticity
Excitability
Conductivity
Contractility

33
Q

The ability of certain cells to produce an electrical impulse without outside nerve stimulation

A

Automaticity

A key property of myocardial cells

34
Q

The ability to respond to an electrical stimulus

A

Excitability

A key property of myocardial cells

35
Q

Ability to transmit an electrical stimulus from cell to cell

A

Conductivity

A key property of myocardial cells

36
Q

Ability to contract when electrically stimulated

A

Contractility

A key property of myocardial cells

37
Q

Specialized cardiac cells that generate and transmit electrical impulses throughout the myocardium

A

The conductive pathway

38
Q

What are the 2 types of cells in the conductive pathway?

A

Pacemaker cells - have the ability to spontaneously generate an impulse at a certain rate

Electrical conducting cells - carry the electrical impulses to the appropriate regions of the heart

39
Q

What are the different pacemaker cells?

A

Sinoatrial (SA) node

Atrioventricular (AV) node

Bundle of His

Right and Left Bundle Branches

Purkinje fibers

40
Q

What is the heart’s primary pacemaker?

A

Sinoatrial (SA) node

Located high in the posterior right atrium

41
Q

What is the intrinsic rate of the SA node?

A

60-100 bpm

42
Q

Pacemaker cells located in the low right atrium

A

AV node - pathway for impulses to reach the ventricles

43
Q

The AV node acts as a _______

A

Gatekeeper for impulses reaching the ventricles by conducting impulses more slowly

44
Q

Intrinsic rate of the AV node

A

40-60 bpm

45
Q

Terminal branches of the right and left bundle branches that spread throughout the myocardium

A

Purkinje fibers

46
Q

Intrinsic rate of the purkinje fibers

A

20-40 bpm

Will take over as pacemaker if the SA and AV nodes fail

47
Q

The polarized state (or resting state) of myocardial cells consists of ______ ions inside the cell and _______ ions outside the cell

A

Negatively charged inside

Positively charged outside

48
Q

The ________ is the difference in the electrical charge between inside and outside the cell

A

Resting membrane potential

49
Q

What is depolarization?

A

When positive ions (Na+) enter the cell, the interior becomes positively charged or “depolarized”

Ca2+ ions also enter, but more slowly

THe change in electrical charge over time is called the action potential of the cell

50
Q

What is repolarization?

A

After the cell is depolarized, the positive ions (Na+, Ca2+, K+) leave the cell and the interior of the cell returns to its negatively charged resting state

51
Q

What it’s he absolute refractory period?

A

Following depolarization, the cell becomes temporarily resistant to further depolarization

This keeps the wave of depolarization moving forward but also prevents spasms of continued contraction in one area

52
Q

What is the relative refractory period?

A

In the late phase of repolarization, a very strong electrical stimulus will cause depolarization

53
Q

Who invented the EKG?

A

Willem Einthoven, a Dutch physician and physiologist in 1903 (won Nobel in 1924)

54
Q

_______ leads have electrodes of opposite polarity (positive and negative)

A

Bipolar

Limb leads - Leads I, II, III

55
Q

______ leads have only a positive electrode and a reference point determined by the ECG machine

A

Unipolar leads

Chest/precordial leads (V1-V6)
Augmented limb leads

56
Q

Movement toward a positive electrode appears ______ the baseline on the ECG tracing

A

Above

57
Q

Movement away from a positive (or towards a negative) electrode appears ______ the baseline

A

Below

58
Q

The ECG records the sum of all…

A

The small directional electrical currents

These are called vectors and their sum is the electrical axis

59
Q

______ = many small electrical currents in various directions

______ = overall direction of the same of the vectors

A

Vectors

Axis

60
Q

The _______ represents atrial depolarization

A

P wave

61
Q

The ______ represents ventricular depolarization

A

QRS wave

62
Q

The _______ represents ventricular repolarization

A

T wave

63
Q

Why is atrial repolarization not represented on the ECG?

A

B/c it’s hidden in the QRS wave

EKG Midterm (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions