Heart

Question 1

What are the contents of the thoracic cavity?

Answer 1

• heart & great vessels
• trachea, bronchi, lungs
• esophagus
• thymus gland

Question 2

Which organ is found in the pleural cavities?

Answer 2

• the lungs

Question 3

What is the mediastinum?

Answer 3

• the space between the lungs

Question 4

Which organ is found in the middle mediastinm?

Answer 4

• the heart

Question 5

What are the three layers of the heart wall?

Answer 5

• epicardium – thin outer layer of connective tissue
• myocardium – thick middle layer of cardiac muscle tissue
• endocardium – thin inner layer of endothelial tissue

Question 6

What is the name of the membrane surrounding thee heart?

Answer 6

• pericardium

Question 7

What is the fibrous pericardium?

Answer 7

• dense connective tissue layer that anchors the heart to the diaphragm and blood vessels entering/exiting the heart

Question 8

What is the serous pericardium?

Answer 8

• thin double-layered membrane with a small fluid-filled space called the pericardial cavity between the layers

Question 9

What are the names of the two layers within the serous pericardium?

Answer 9

• parietal layer (outer layer fused to the fibrous pericardium)
• visceral layer (inner layer fused to the heart/epicardium)

Question 10

What are the four chambers of the heart?

Answer 10

• left atrium & right atrium (receives blood)

- left ventricle & right ventricle (ejects blood)

Question 11

Which ventricle is the thickest?

Answer 11

• the left ventricle

Question 12

What are the names of the four valves of the heart?

Answer 12

• right semilunar/pulmonary valve
• left semilunar/ aortic valve
• tricuspid valve (r)
• bicuspid valve (l)

Question 13

What are the names of the sulci on the external surface of the heart?

Answer 13

• coronary sulcus

- interventricular sulci

Question 14

What is the coronary sulcus?

Answer 14

• encircles the heart and roughly marks the external boundary between the atria and ventricles

Question 15

What are the interventricular sulci?

Answer 15

• grooves on the anterior and posterior surface that

roughly mark the external boundary between the ventricles

Question 16

What is the name of the ear shaped pouch that extends out from the anterior surface of each atrium?

Answer 16

• an auricle

Question 17

What is the purpose of the auricles?

Answer 17

• allows each chamber to hold more blood

Question 18

Is the apex of the heart at the bottom or the top?

Answer 18

• bottom

Question 19

What are some of the great vessels that surround the heart?

Answer 19

• superior and inferior vena cava
• aorta
• pulmonary arteries
• pulmonary trunk
• pulmonary veins

Question 20

What is systemic circulation/

Answer 20

• system of blood vessels that carry oxygenated blood from the heart to the majority of the body and return deoxygenated blood to the heart
• therefore, the blood LOSES oxygen in this circuit

Question 21

What is pulmonary circulation?

Answer 21

• system of blood vessels that carry deoxygenated blood from the heart to the lungs and return oxygenated blood to the heart
• therefore, the blood GAINS oxygen in this circuit

Question 22

Explain the steps of systemic circulation.

Answer 22

1) the right atrium receives blood from the superior vena cava and inferior vena cava
2) blood passes through the tricuspid valve into the right ventricle
3) blood passes through the pulmonary valve
into the pulmonary trunk
4) blood passes into the pulmonary arteries and enters the pulmonary circulation

Question 23

Explain the steps of pulmonary circulation.

Answer 23

5) The left atrium receives blood from the pulmonary veins
6) Blood passes through the
bicuspid valve into the left ventricle
7) Blood passes through the aortic valve into the aorta
8) Blood enters the systemic circulation

Question 24

What do arteries do?

Answer 24

• carry blood AWAY from the heart

- most carry oxygenated blood

Question 25

What do veins do?

Answer 25

- carry blood toward the heart | - most carry deoxygenated blood

Question 26

What is coronary circulation?

Answer 26

- network of blood vessels encircling the heart that delivers oxygenated blood to and removes deoxygenated blood from the heart tissue

Question 27

Where do coronary arteries branch out of?

Answer 27

- branch out from the aorta near where it emerges from the left ventricle

Question 28

Where do coronary veins drain?

Answer 28

- drain into a coronary sinus, which itself drains directly into the right atrium

Question 29

What are the main coronary arteries? (7)

Answer 29

- aorta - left coronary artery - circumflex branch - anterior interventricular artery - right coronary artery - posterior interventricular artery - marginal branch

Question 30

What is myocardial infraction?

Answer 30

- damage to heart muscle due to a lack of oxygen

Question 31

What are symptoms of a myocardial infraction?

Answer 31

- pain/pressure, shortness of breath, nausea, sweating, lightheadedness

Question 32

How can a myocardial infraction be diagnosed?

Answer 32

- electrocardiogram (ECG), cardiac enzymes (blood test)

Question 33

What are the main coronary veins? (5)

Answer 33

- small cardia vein - anterior cardiac vein - middle cardiac vein - coronary sinus - great cardiac vein

Question 34

What is the cardiac conduction system?

Answer 34

- is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract

Question 35

What allows the heart to beat?

Answer 35

- unique features of cardiac muscle cells allow the heart to contract (beat) in a coordinated and rhythmical manner

Question 36

What is the small small channel that connect cardiac muscle cells called?

Answer 36

- gap junctions

Question 37

Which cardiac muscle cells are "self-excitable"?

Answer 37

- autorhythmic fibres

Question 38

What are the steps of cardiac conduction?

Answer 38

1.) cells in the sinoatrial (SA) node located in the wall of the right atrium spontaneously depolarize, leading to the generation of an action potential 2) the action potential spreads through the right and left atria via gap junctions, causing contraction of the atria 3) the action potential reaches cells in the atrioventricular (AV) node located in the interatrial septum 4) the action potential travels down the AV bundle (“bundle of His”) and conducting fibres in the interventricular septum to the apex of 5) the action potential spreads through the left and right ventricles via Purkinje fibres in the ventricular walls, causing contraction of the ventricles

Question 39

What are the two nodes in the heart?

Answer 39

- SA node | - AV node

Question 40

What is hypertrophic cardiomyopathy?

Answer 40

- condition that leads to an enlargement of the myocardium, which causes a disruption of the electrical conduction system of the heart - can lead to sudden cardiac death

Question 41

What is the cardiac cycle?

Answer 41

- all of the events that take place during one heartbeat

Question 42

Describe the sounds of the heart through a stethoscope.

Answer 42

- “lub” (first sound) = AV valves closing | - “dub” (second sound) = semilunar valves closing

Question 43

How are AV valves connected papillary muscles in the walls of the ventricles?

Answer 43

- tendon-like cords called chordae tendinae