The Heart

Question 1

Describe the structure and function of the heart

Answer 1

“double pump” with 4 chambers–2 atria and 2 ventricles; right side pumps into the pulmonary circuit and left side pumps into the systemic circuit

Question 2

What are veins?

Answer 2

Low-pressure vessels that carry blood back to the heart

Question 3

What are arteries?

Answer 3

High-pressure vessels that carry blood away from the heart

Question 4

Describe the pressure gradient of the circulatory system

Answer 4

Blood flows from high-pressure to low pressure; artery pressure lessens the further it gets from the heart, lessens in the capillary bed, and lessens even more in veins

Question 5

Describe distribution of pressure in the heart

Answer 5

Least pressure in the body where receiving blood from veins; highest pressure in the body where pushing blood into arteries

Question 6

Why is there less muscle on the right side of the heart than the left?

Answer 6

The pulmonary circuit requires less pressure from the heart for blood to flow; the left side of the heart needs to create immense pressure to pump blood throughout the body

Question 7

What chambers pump blood out of the heart?

Answer 7

Ventricles

Question 8

Describe the path blood takes through the heart/circuits

Answer 8

Deox. blood flows into right A, down into right V, pumped into pulmonary trunk and into lungs via pulmonary arteries; oxygenated at pulmonary capp, carried back via pulmonary veins into left A, down into left V, pumped into aorta and into arteries to body; returned through veins into inf/sup vena cava into right A

Question 9

What is the aorta?

Answer 9

Structure of the heart where ALL systemic arteries branch from

Question 10

How does the heart receive blood TO THE CARDIAC MUSCLE?

Answer 10

capillaries!

Question 11

Does gas exchange occur in the chambers of the heart?

Answer 11

NO! It has its own blood supply through coronary circulation

Question 12

Describe coronary circulation

Answer 12

Special branch of the systemic circuit that supplies blood to the cardiac muscle–coronary artery carries blood from the aorta to the heart itself, gas exchange happens in capillaries of the heart, cardiac veins carry blood to coronary sinus that drains into vena cava

Question 13

What causes coronary artery disease?

Answer 13

Blockage of the coronary arteries

Question 14

What causes angina (chest pain)?

Answer 14

Lack of oxygen to the heart when it needs to work harder (i.e. during physical activity)

Question 15

What causes myocardial infarction (heart attack)?

Answer 15

Damage to the cardiac muscle, usually from lack of oxygen

Question 16

What is the pericardium?

Answer 16

Connective tissue membranes that surround the heart

Question 17

Identify the layers of the pericardium

Answer 17

Parietal pericardium is the outer layer in contact with the tissues of the body; visceral pericardium is the inner layer in contact with the cardiac muscle

Question 18

What is the pericardial fluid?

Answer 18

Fluid found in between the layers of the pericardium; reduces friction between the cardiac muscle and tissues of the body

Question 19

What are the valves of the heart?

Answer 19

structures that separate areas of the heart

Question 20

What do the atrioventricular valves do?

Answer 20

separate atria and ventricles

Question 21

What do the semilunar valves do?

Answer 21

separate ventricles from circulation; found at the base of the pulmonary trunk and aorta

Question 22

What are the chordae tendinae?

Answer 22

“heart strings” that hold the AV valves in place

Question 23

What is another name for the right AV valve and why?

Answer 23

Tricuspid valve; three flaps

Question 24

What is another name for the left AV valve?

Answer 24

Bicuspid; two flaps–also mitral valve (less common for purpose of this class, more common in caridology)

Question 25

Why are there no cordae tendinae on the semilunar valves?

Answer 25

Pressure is less here than at the ventricles, so “blowout” of the valves backwards is unlikely

Question 26

Describe the arrangement of muscle fibers in the heart

Answer 26

A sort of figure 8, creates a wringing motion that squeezes blood up and out

Question 27

What is the fibrous skeleton of the heart?

Answer 27

Connective tissue rings that surround the AV valves, separating atria from ventricles