Cardiac Conduction

Question 1

What 2 ions have a rapid exchange in cardiac cells?

Answer 1

Sodium and potassium

Question 2

During depolarization potassium _____ and sodium ———

Answer 2

• leaves
• enters

Question 3

During depolarization potassium _____ and sodium ——-

Answer 3

• leave
• enters

Question 4

Cardiac mitochondria produce more than 95% of energy or _____

Answer 4

ATP

Question 5

What is ATP

Answer 5

An immediate source of energy for cardiac muscle contraction

Question 6

Components of contraction (5)

Answer 6

• force
• time
• velocity
• length
• muscle

Question 7

What are the parts of the conduction system?

Answer 7

• SA node
• Bachmanns bundle
• AV node
• bundle of his
• right and left bundle branches
• purkinji fibers

Question 8

What is considered the pacemaker?

Answer 8

The SA node

Question 9

What is the firing rate if the SA node?

Answer 9

60-100 beats per min

Question 10

What does the AV node do?
- what is the firing rate?

Answer 10

• it hold the electrical impulse to allow time for the atria to fully empty before ventricular contraction
• 40-60 beats / min

Question 11

What is the bundle of HIS

Answer 11

It leaves the AV node and splits into the right and left bundle branches

Question 12

What is the firing rate for the bundle of his and purkinji fibers?

Answer 12

15-40 beats/ min

Question 13

Where do purkinji fibers spread along?

Answer 13

The endocardium of the lower parts of the ventricles to contract before the upper parts

Question 14

What’s the frank starling law?

Answer 14

The greater the stretch of the heart fibers , the stronger the contraction

Question 15

After load is the force of the myocardium must generate to eject blood from _____ into the _____or ______

Answer 15

• ventricle
• aorta
• pulmonary artery

Question 16

What is interval strength relationship?

Answer 16

The longer the interval between each cardiac contraction, the stronger the strength of contraction

Question 17

____ is the end diastolic volume
( preload or afterload?)

Answer 17

Preload

Question 18

Preload is related to the ________. A higher end diastolic volume implies higher preload

Answer 18

Ventricular end diastolic volume

Question 19

As pressure rises or falls in the chamber, the corresponding pressure in another chamber will what?

Answer 19

Rise and fall

Question 20

Premature closing of the MV/TV can be a result of what?

Answer 20

Prolonged PR interval

Question 21

In an EKG the direction the wave is pointing indicates what?

Answer 21

Whether it is moving toward or away from a lead

Question 22

What happens during the P wave

Answer 22

Atrial depolarization

Question 23

What happens during the QRS complex?

Answer 23

Ventricular depolarization

Question 24

What happens in the T wave?

Answer 24

Ventricular repolarization

Question 25

What is the PR segment on an EKG?

Answer 25

Represents time from the end of aerial depolarization to the start of ventricular depolarization

Question 26

What is the PR INTERVAL?

Answer 26

Represents DELAY between atrial and ventricular depolarization

Question 27

What is the ST segment on an EKG?

Answer 27

Represents the end of the ventricular depolarization to the beginning of the ventricular repolarization

Question 28

What is a premature ventricular contraction?

Answer 28

A premature QRS complex or one that occurs without being preceded by a P WAVE

Question 29

What happened in ventricular fibrillation?

Answer 29

Waves of depolarization traveling in multiple directions all over the ventricular muscle

Question 30

What happens with atrial fibrillation?

Answer 30

Same as what happens with ventricular fibrillation