Chapter 18

Question 1

mediastinum

Answer 1

medial cavity of the thorax where the heart resides

Question 2

pericardium

Answer 2

outer double-walled sac around the heart; outer fibrouse, inner serous

Question 3

myocardium

Answer 3

medial cardiac muscle layer of the heart

Question 4

endocardium

Answer 4

inner, thin endothelial lining of the heart’s chambers

Question 5

coronary arteries

Answer 5

first branch off of the aorta; arteries that feed the heart tissue

Question 6

coronary sinus

Answer 6

part of the coronary veins that drain blood from the coronary circulation and dump into the RA

Question 7

angina pectoris

Answer 7

chest pain caused by blood deficiencies to the heart

Question 8

myocardial infarction

Answer 8

• heart attack; caused by a blockage of a coronary artery

- leads to death of myocardium

Question 9

cardiac tamponade

Answer 9

• heart is compressed by fluid
• restricts ability of heart to pump blood
• can be due to trauma, severe inflammation, or viral infection

Question 10

mitral valve prolapse

Answer 10

• 1 or more mitral valves are incompetent and balloons into LA
• blood regurgitates there lowering LV ejection fraction
• found in 10% of population, mostly young women

Question 11

stenosis

Answer 11

• valves narrowed due to stiff flaps from scar formation

- constricts opening so heart contracts more forcibly than normal to eject all blood from atrium

Question 12

cardiac output

Answer 12

volume of blood pumped out by each ventricle in 1 minute

Question 13

stroke volume

Answer 13

volume of blood pumped out by 1 ventricle w/ each contraction

Question 14

heart sounds

Answer 14

• caused by the closing of the valves
• “lub” is the closing of the tricuspid and bicuspid valves
• “dub” is the closing of the semilunar valves

Question 15

arrhythmias

Answer 15

irregular heartbeat

Question 16

fibrillation

Answer 16

rapid, out of phase contractions

Question 17

tachycardia

Answer 17

abnormally fast heart rate; greater than 100 BPM

Question 18

bradycardia

Answer 18

abnormally slow heart rate; lower than 60 BPM

Question 19

systole

Answer 19

• top number in BP; peak pressure in the arteries

- occurs when the ventricles are contracting

Question 20

diastole

Answer 20

• bottom number in BP; minimum pressure in the arteries

- occurs when the ventricles are filled with blood

Question 21

pulse pressure

Answer 21

systolic minus diastolic; normal is 40

Question 22

baroreceptors

Answer 22

• mechanoreceptor found in the BVs that detects the pressure of blood flowing through them
• can send messages to the CNS to increase or decrease cardiac output

Question 23

extrasystole

Answer 23

premature contraction before the SA node initiates the next contraction

Question 24

asystole

Answer 24

when the heart fails to contract

Question 25

hypocalcemia

Answer 25

low blood calcium; depresses the heart

Question 26

hypernatremia

Answer 26

too much sodium; blocks heart contraction

Question 27

hyper/hypokalemia

Answer 27

- too much or too little potassium | - hyper > cardiac arrest; hypo > arrhythmias

Question 28

congestive heart failure (CHF)

Answer 28

- heart is too weak to pump efficiently so blood backs up - left side failure > fluid back up in the lungs - right side failure > swelling in the extremities/organs

Question 29

foramen ovale

Answer 29

hole in the wall between the atria

Question 30

ductus arteriosus

Answer 30

tube that connects the pulmonary artery and the aorta

Question 31

pulmonary circuit

Answer 31

- deoxygenated blood from heart > lungs | - oxygenated blood back > heart (PV>LA)

Question 32

systemic circuit

Answer 32

oxygenated blood leaves aorta via LV and comes back via veins and venae cavae to right side of heart

Question 33

pericarditis

Answer 33

inflammation of pericardium; build up of fluid

Question 34

intercalated discs

Answer 34

allows muscles to contract ensync

Question 35

heart murmers

Answer 35

abnormal heart sounds due to blood flow obstructions