16 The Heart

Question 1

On average, how often does the heart beat per minute? per day?

Answer 1

75/min

108,000/day

Question 2

What is the average cardiac output?

Answer 2

5.25 L/minute

Question 3

What chambers of the heart are involved in the pulmonary circuit?

Answer 3

Right atrium and ventricle

Question 4

What heart chambers are involved in the systemic circuit?

Answer 4

Left atrium and ventricle

Question 5

What chamber receives de-oxygenated blood from systemic circuit?

Answer 5

Right atrium

Question 6

What heart chamber receives oxygenated blood from pulmonary circuit?

Answer 6

Left atrium

Question 7

What area of the heart is the ‘base’?

Answer 7

the posterior and superior surface of the heart

Question 8

What area of the heart is the ‘apex’?

Answer 8

the anterior and inferior portion, the ‘point’, which points toward left hip.

Question 9

What is the pericardium?

Answer 9

Triple layer sack which encloses the heart.

Question 10

What are the layers of the pericardium?

Answer 10

Fibrous pericardium, parietal pericardium, visceral pericardium

Question 11

What is the pericardial cavity and what fills that space?

Answer 11

it is the space between the parietal and visceral pericardium. Filled with lubricating serous fluid.

Question 12

What are the functions of the pericardium?

Answer 12

prevents undesired movement of heart
Prevents overfilling of heart
Reduces friction

Question 13

What are the layers of the heart wall?

Answer 13

Epicardium
Myocardium
Endocardium

Question 14

What is another name by which the heart’s epicardium is named?

Answer 14

visceral pericardium

Question 15

What is the fibrous skeleton of the heart?

Answer 15

A region of connective tissue between ventricles and atrium

Question 16

What is the purpose of the fibrous skeleton of the heart?

Answer 16

Anchors heart valves
Provides electrical insulation between atria and ventricles
Provides framework for attachment of heart muscles.

Question 17

What is the structural precursor of the fossa ovalis?

Answer 17

Foramen ovale which allowed blood to bypass pulmonary circuit during fetal period

Question 18

What is systole?

Answer 18

contraction of a heart chamber

Question 19

What is diastole?

Answer 19

Relaxation of a heart chamber

Question 20

What is the conducting system of the heart? What is the order of impule travel?

Answer 20

1. Sinoatrial node (SA node)
2. Atrioventricular node (AV node)
3. Atrioventricular bundle (AV bundle) or Bundle of His
4. Right and Left bundle branches
5. Purkinje Fibers

Question 21

What are the divisions of the coronary plexus?

Answer 21

Sympathetic and parasympathetic divisions

Question 22

What nerves provide sympathetic innervation to the heart and what function does sympathetic innervation perform?

Answer 22

T1-T5, increasing the rate and force of heart contraction

Question 23

What nerves cause parasympathetic innervation and what is their function?

Answer 23

Medulla oblongate and vagus nerve X. Decrease the rat and force of heart contraction.

Question 24

What are the symptoms of congestive heart failure?

Answer 24

enlarged heart, progressive decrease in pumping efficiency, pulmonary edema.

Question 25

What is a myocardial infarction and what is its other name? What does it cause?

Answer 25

a blockage of coronary arteries by blood clot or plaque. Commonly called heart attack. Causes death of heart muscle.