Chapter 20/21 The Heart

Question 1

Where is the heart located?

Answer 1

Mediastinum

Question 2

The heart is enclosed and held in place by what?

Answer 2

The pericardium

Question 3

The pericardium consist of what?

Answer 3

1. outer fibrous pericardium
2. inner serous pericardium

Question 4

The serous pericardium has 2 layers what are they?

Answer 4

1. Visceral
2. Parietal

Question 5

What is the parietal and visceral layer separated by?

Answer 5

A serious cavity and a fluid filled space

Question 6

What is the right atrium?

Answer 6

Receives blood from the superior and inferior vena cava

Question 7

What is the right ventricle?

Answer 7

Receives blood from the right atrium and sends the blood to the lungs

Question 8

What is the left atrium?

Answer 8

Receives blood from the pulmonary veins

Question 9

What is the left ventricle?

Answer 9

Receives blood from the the left atrium and pumps blood to the entire body

Question 10

Which ventricle has the thicker wall?

Answer 10

The left one does because it needs to pump blood to the whole body

Question 11

What is the fibrous skeleton?

Answer 11

1. forms the foundation for which the heart valves attach
2. serves as a point of insertion for cardiac muscle
3. prevents overstretching of the heart values
4. acts as an electrical insulator

Question 12

What are the three walls of the heart?

Answer 12

1. Epicardium
2. Myocardium
3. Endocardium

Question 13

The valves of the heart open and close in response to what?

Answer 13

Pressure changes as the heart contracts and relaxes

Question 14

What does the right and left atrioventricular valves do?

Answer 14

Prevent back flow form the ventricles into the atria

Question 15

What does the right and left semilunar values do?

Answer 15

Prevent back flow from the arteries into the ventricles

Question 16

Blood flows through the coronary arteries to delivery what to where?

Answer 16

Oxygenated blood and nutrients to the myocardium

Question 17

Coronary veins remove what?

Answer 17

Carbon dioxide and wastes from myocardium

Question 18

What is myocardial ischemia?

Answer 18

Reduced blood flow to the myocardium

Question 19

What is myocardial infarction?

Answer 19

Heart attack. Infarction refers to death of tissues due to interrupted blood supply

Question 20

What can myocardial ischemia cause?

Answer 20

Hypoxia (reduced oxygen supply) and angina pectoris (severe pain in the chest) and pain in the neck, chin, left arm and elbow

Question 21

Cardiac muscles are self excitable and therefore what?

Answer 21

Autorhythmic

Question 22

Cardiac muscle cells repeatedly generate what?

Answer 22

Spontaneous action potentials that then trigger heart contractions

Question 23

Cardiac muscle cells form what?

Answer 23

The conduction system, which is the route for propagating action potentials through the heart muscle

Question 24

The autorhythmic fibers in the SA (sinuatrial) node are what?

Answer 24

The natural pacemaker of the heart because they initiate action potentials most frequently

Question 25

Signals from the nervous system and hormones (like epinephrine) can do what?

Answer 25

Modify the heart rate and force of contraction but they do not set the fundamental rhythm

Question 26

What is the pathway of the conduction system?

Answer 26

1. SA node 2. AV node 3. AV bundle 4. Right and left bundle branches 5. subendocardial conducting network

Question 27

What is a electrocardiogram (EKG or ECG)?

Answer 27

Recording of the electrical changes that accompany each heart beat

Question 28

What is the cardiac cycle?

Answer 28

One cardiac cycle consists of 1. contraction (systole) of both atria 2. relaxation (diastole) of both atria 3. rapidly followed by systole and diastole of both ventricles

Question 29

What are the elements of the cardiac cycle?

Answer 29

1. Electrical events 2. Pressure changes 3. Heart sounds 4. Volume changes 5. Mechanical events

Question 30

What is cardiac output?

Answer 30

The volume of blood ejected from the left or right ventricle into the aorta or pulmonary trunk each minute

Question 31

Stroke volume (SV) is what?

Answer 31

The amount of blood pumped out of the ventricle in one beat

Question 32

What is the Cardiac output formula?

Answer 32

CO = SV x HR

Question 33

What are some of the several factors that regulate heart rate?

Answer 33

1. Autonomic nervous system 2. Hormones 3. Ions 4. Age 5. Gender 6. Physical fitness 7. Temperature

Question 34

What are some homeostatic imbalances?

Answer 34

1. Coronary artery disease 2. Atherosclerotic plaques 3. Congenital heart defects 4. Arrhythmia 5. Congestive heart failure

Question 35

In the Cardio vascular system what does aging result in?

Answer 35

1. Loss of compliance of the aorta 2. Reduction in cardiac muscle fiber size 3. Progressive loss of cardiac muscular strength 4. Decline in maximum heart rate 5. Increased systolic blood pressure