Week 8

Question 1

what is the portion of the cavity in which the heart lies?

Answer 1

it lies within the mediastinum in the thoracic cavity.

Question 2

what is the specific division of the thoracic cavity in which the heart is encased?

Answer 2

the pericardial cavity

Question 3

what is the hearts relationship to the ribs, sternum, vertebrae in terms of location?

Answer 3

the heart lies medially between the lungs, the back of the heart lies near the bodies of the vertebrae, and the anterior side of the heart sits deep to the sternum and costal cartilages.

Question 4

apex vs base of the heart?

Answer 4

apex is the pointed inferior tip of the heart and it lies between the 4th and 5th ribs and the base is the broader superior portion of the heart located at the level of the 3rd coastal cartilage.

Question 5

what is the pericardium?

Answer 5

the pericardium is a double walled membrane that surrounds the heart and has two sublayers.

Question 6

what are the 2 sublayers of the pericardium?

Answer 6

fibrous pericardium: the outer layer that anchors the heart to surrounding structures and protects.
serous pericardium: inner layer that divides further into parietal and visceral layer. between the parietal and visceral layer is pericardial cavity which contains the serous fluid that reduces friction and acts as a lubricant.

Question 7

what are the layers of the heart wall?

Answer 7

epicardium: thin connective tissue and epithelium
myocardium: cardiac muscle tissue cardiomyocytes
endocardium: endothelial cells supported by connective tissue

Question 8

what is the right and left atria?

Answer 8

right atrium: upper right chamber of the heart
function: receives deoxygenated blood from the body through superior and inferior vena cava and pumps into right ventricle.
left atrium: upper left chamber of the heart.
function: receives oxygenated blood from the lungs through the pulmonary veins and pumps it into the left ventricle.

Question 9

tricuspid valve?

Answer 9

prevents backflow of blood from right ventricle to the right atrium during contraction.

Question 9

what is the right and left ventricles?

Answer 9

right ventricle: lower right chamber of the heart
function: pumps deoxygenated blood to the lungs through the pulmonary arteries for oxygenation.
left ventricle: lower left chamber of the heart
function: pumps oxygenated blood to the rest of the body through the aorta.

Question 10

bicuspid valve?

Answer 10

prevents backflow of blood from left ventricle into left atrium.

Question 11

pulmonary semilunar valve?

Answer 11

prevents backflow of blood from the pulmonary artery into the right ventricle

Question 12

aortic semilunar valve?

Answer 12

prevents backflow of blood from the aorta into the left ventricle

Question 13

chordae tendinae?

Answer 13

maintains proper av valve function regulating blood flow in one direction

Question 14

papillary muscles?

Answer 14

anchor the chordae tendinae and maintain valve function.

Question 15

superior and inferior vena cava?

Answer 15

superior vena cava returns blood from upper half of the body to the right atrium and the inferior vena cava returns bloos from the lower half of the body to the right atrium of the heart.

Question 16

pulmonary artery?

Answer 16

transports deoxygenated blood from the heart to the lungs and helps regulate blood pressure in lungs.

Question 17

pulmonary veins?

Answer 17

transport oxygen rich blood from the lungs to the left atrium of the heart.

Question 18

aorta?

Answer 18

distribute oxygen rich blood from left ventricle to all parts of the body.

Question 19

coronary sinus?

Answer 19

the coronary sinus collects deoxygenated blood from the heart muscle(myocardium) through the cardiac veins and empties this into the right atrium of the heart.

Question 20

interventricular septum?

Answer 20

thick wall that runs down the middle of the heart separating the right and left ventricles of the heart. it prevents mixing of the deoxygenated and oxygenated blood.

Question 21

fibrous skeleton?

Answer 21

provides framework for the heart valves and attachment point for the myocardium and cardiac muscle fibers.

Question 22

where do the coronary arteries originate from?

Answer 22

they originate from the ascending aorta.

Question 23

areas supplied by each coronary artery?

Answer 23

right coronary artery supplies blood to the right atrium and right ventricle and the left coronary artery provides blood to the left ventricle and left atrium.

Question 24

why do the myocardium of the ventricles receive the best blood supply?

Answer 24

the ventricles especially the left ventricle work hard to pump blood throughout the body so they have a high oxygen requirement. the coronary arteries have specific branches to make sure high demand areas receive enough blood supply.

Question 25

whats the function of the coronary sinus?

Answer 25

collects deoxygenated blood from the myocardium and returns it to the right atrium of the heart.

Question 26

describe the myocardium stuff…

Answer 26

cardiomyocytes are striated, interconnected by intercalated discs which contain the gap junctions and desmosomes. the function is: essential for heart contraction and the desmosomes provide mechanical strength.

Question 27

briefly describe the conduction system of the heart.

Answer 27

specialized network of cardiac muscle cells myocytes responsible for transmitting electrical impulses that ensure coordinated contraction of the hearts chambers.

Question 28

say blood flow

Answer 28

superior and inferior vena cava return deoxygenated blood from the body to the right atrium and so does the coronary sinus. the right atrium receives it and pushes it through the tricuspid valve into the right ventricle. the right ventricle sends through the pulmonary semilunar valve into the pulmonary arteries that carry the blood to the lungs for oxygenation. the pulmonary veins return the oxygenated blood to the left atrium and then pushes through bicsupid valve into left ventricle. then the left ventricle pushes through the aortic semilunar valve into the aorta which distributes to the rest of the body.

Question 29

How is the structure of the wall of the right ventricle different from the wall of
the left ventricle.?

Answer 29

the left ventricle has a thicker wall than the right ventricle.

Question 30

how does the wall of a vein differ from the wall of artery in thickness and elasticity.

Answer 30

artery wall is thicker than vein and more elastic.

Question 31

another name for muscular folds?

Answer 31

papillary muscles attached to chordae tendinae.