Exam #2

Question 1

Pericardium

Answer 1

Outer covering of heart
2 serous membranes
2 layers: outer fibrous and inner visceral layer (epicardium)

Question 2

Myocardium

Answer 2

Muscular tissue of heart walls

Question 3

Endocardium

Answer 3

Connective tissue that lines heart chambers

Question 4

Preload

Answer 4

Force that stretches ventricles from blood entering

Question 5

Contractibility

Answer 5

Force contraction of our heart muscle

Question 6

Afterload

Answer 6

Pressure ventricles need to overcome in large vessels to eject blood out (aorta and pulmonary trunk)

Question 7

End diastolic volume

Answer 7

Amount of blood in ventricles after they are full (high pressure)

Question 8

End systolic volume

Answer 8

Amount of blood in ventricle after contracting (low pressure)

Question 9

Cardiac output

Answer 9

Amount of blood pumped out of blood in 1 minute

Question 10

Plateau phase of contractile cell

Answer 10

K+ is closed in depolarization and plateau
K+ is open in repolarization

Na+ is closed in plateau and repolarization
Na+ is open in depolarization

Ca2+ is closed in depolarization and repolarization
Ca2+ is closed in plateau

Question 11

What are the steps in the conduction system

Answer 11

1. SA node depolarize from pacemaker cells
2. A/V node pause in depolarization to allow atria to finish contracting
3. A/V bundle link between atria and ventricle junction
4. Bundle branches branch will split can become blocked
5. Purkinje fibers branch throughout ventricular mascular wall

Question 12

Where are the cardioinhibitory and cardioacceleratory centers located

Answer 12

Medulla oblongata

Question 13

Parasympathetic

Answer 13

Slows heart rate synapses with S/A node, A/V node, and right atrium

Question 14

Sympathetic

Answer 14

Increase heart rate synapse with S/A node, A/V node, and right and left atria and right and left ventricles

Question 15

What happens during a heart block

Answer 15

Partial: conduction through A/V node is slowed or partially blocked

Complete: no impulses get through the A/V node
Ventricles beat at their own intrinsic rhythm
Circulation can not be maintained
An artificial pacemaker may be implanted

Question 16

First heart sound

Answer 16

A/V valves closing
Isovolumetric contraction phase
High pressure in ventricles
(end diastolic volume measured)

Question 17

Second heart sound

Answer 17

S/L valves closing
isovolumetric relaxation phase
HIgh pressure in large vessels
(end systolic volume measured)

Question 18

What is required for cardiac fibers to contract?

Answer 18

Extracellular calcium activates the release of sarcoplasmic reticulum calcium to be released causes contractions

Question 19

What happens to the cardiac cycle when exercising skeletal muscle?

Answer 19

The most important factor stretching cardiac muscle is venous return

Question 20

What increases cardiac output?

Answer 20

Positive Inotropic
(increase body temp, preload, and norephrine)

Question 21

What decreases cardiac output?

Answer 21

Negative Inotropic

Question 22

What side of the heart pumps more blood then the other and why?

Answer 22

It pumps out the same amount because of different pressures left will be higher but it will be the same amount of blood

Question 23

Hypokalemia

Answer 23

Decreases potassium and increased contractility

Question 24

Does heart rate go down when you get older?

Answer 24

Yes

Question 25

Who has higher heart rates men or women

Answer 25

Men

Question 26

P wave

Answer 26

Atrial depolarization

Question 27

Qrs complex

Answer 27

Ventricle depolarization
Atrial repolarization

Question 28

T wave

Answer 28

Ventricular repolarization

Question 29

Ectopic focus

Answer 29

An abnormal pacemaker

May occur if SA node is defective

Pace set by AV node (junctional rhythm)

Slower than sinus rythum 40-60 bpm but adequate to maintain circulation

Question 30

Membrane potential chart

Answer 30

1. Pacemaker potential (sodium)
2. Depolarization (calcium)
3. Repolarization (potassium)

Question 31

What is ductus arteriosus

Answer 31

Duct in fetal heart that bypasses the lungs since they are not developed in a fetus