The Heart + Electro

Question 1

Where does the heart sit

Answer 1

Between the lungs, retrosternal against the 5th to 8th thoracic vertebrae

Question 2

Functions of the heart

Answer 2

Generating blood pressure, pushing blood through pulmonary and systemic routes, ensuring one at blood valve, regulating blood supply to meet needs

Question 3

Pericardium

Answer 3

Fibrous sac the surrounds and anchors the heart

Question 4

Layers of the heart wall

Answer 4

Outer - epicardium
Middle - Myocardium
Inner - Endocardium

Question 5

Left coronary artery

Answer 5

Divides into left anterior descending artery

Question 6

Right coronary artery

Answer 6

Divides into right marginal artery, and Paterson interventricular artery

Question 7

Left Circumflex artery supplies

Answer 7

Left atrium and left ventricle

Question 8

Left anterior descending artery supplies

Answer 8

Right ventricle, left ventricle, septum

Question 9

Left Marginal Artery supplies

Answer 9

Left ventricle

Question 10

Right marginal artery supplies

Answer 10

Right ventricle and apex

Question 11

Right coronary artery

Answer 11

Right atrium and right ventricle

Question 12

What is secreted for SNS

Answer 12

Epi and norepi

Question 13

What is secreted from PSNS

Answer 13

Acetylcholine

Question 14

Properties of cardiac cells

Answer 14

Contractility
Automaticity
Rhythmicity
Conductivity
Refractory Period

Question 15

Cardiac Output

Answer 15

Volume of blood ejected in one minute

Question 16

Stroke Volume

Answer 16

Blood pumped out of the left ventricle during each contraction

Question 17

Preload

Answer 17

Stretch of the ventricle at the end of diastole

Question 18

After load

Answer 18

Amount of force the heart must pump against

Question 19

Starlings Law

Answer 19

The more the muscle fibers are stretched, the greater the force of contraction

Question 20

Main function of electrical conduction system

Answer 20

To create electrical impulse and transmit it to rest of myocardium

Question 21

Pacemaker

Answer 21

Dictate the rate at which the heart will cycle through its pumping cycle
SA node acts as main pacemaker

Question 22

Pacemaker settings

Answer 22

SA Node = 60-100
Atrial cells = 55-60
AV Node = 40-60
Bundle of HIS = 40-45
Bundle Branch = 40-45
Purkinje = 20-40

Question 23

AV node

Answer 23

Controls heart rate, to atria to fully contract and ventricles to fully fill before contracting

Question 24

Polarization

Answer 24

State of readiness
Na and C outside
K inside

Question 25

Depolarization

Answer 25

Contraction
Na and C in cell
K outside

Question 26

Repolarization

Answer 26

Recovery phase
K moves back

Question 27

Absolute refractory

Answer 27

Brief period where cell will resist re-stimulation
Absolute - will not respond to any stimulus

Question 28

Relative refractory

Answer 28

Few ms after absolute, the membrane will only respond to very strong stimuli

Question 29

P wave

Answer 29

Represents atrial depolarization

Question 30

QRS Complex

Answer 30

Ventricular depolarization

Question 31

T wave

Answer 31

Represents ventricular repolarization