HLTH cardiovascular system review

Question 1

where is the heart located?

Answer 1

in the mediastinum between the lungs, and is enclosed in the double-walled pericardial sac

Question 2

3 layers of the heart

Answer 2

epicardium (visceral), myocardium, and endocardium

Question 3

what forms the heart valves?

Answer 3

endocaridum

Question 4

mitral valve

Answer 4

on the left side; aka bicuspid valve

Question 5

tricuspid valve

Answer 5

on the right side

Question 6

what causes heart contractions?

Answer 6

the myocardial fibres

Question 7

desmosomes

Answer 7

discs that connect the muscle cells of the heart to prevent them from separating during contractions

Question 8

gap junctions in the heart

Answer 8

permit ions from passing from cell to cell, thus facilitating rapid transmission of impulses

Question 9

conduction pathway for the heart

Answer 9

SA node to AV node, down the bundle of his, through the left and right bundle branches, and then the purkinje network of fibres

Question 10

where is the SA node located?

Answer 10

in the right atrium

Question 11

what creates the sinus rhythm?

Answer 11

the SA node, as it is the pacemaker

Question 12

where is the AV node located?

Answer 12

the floor of the right atrium, near the septum

Question 13

P wave of an ECG

Answer 13

measures the depolarization of the atria

Question 14

QRS wave of an ECG

Answer 14

shows the ventricular depolarization; also is where atrial repolarization occurs but this is masked

Question 15

T wave of an ECG

Answer 15

shows the repolarization of the ventricles

Question 16

what do ECGs test for?

Answer 16

arrhythmias or dysrthythmias, systemic problems, or electrolyte imbalance

Question 17

infarction

Answer 17

death of a tissue resulting from failure of blood supply, often from an obstruction of a vessel

Question 18

what and where is heart rate controlled?

Answer 18

by the cardiac control centre in the medulla

Question 19

what detect changes in blood pressure?

Answer 19

baroreceptors in the wall of the aorta and the internal carotid arteries

Question 20

beta-adrenergic receptors

Answer 20

often a site of actions for drugs such as beta blockers; work to prevent normal SNS stimulation and thus block any increases in heart rate

Question 21

factors that may increase heart rate

Answer 21

elevated body temperature through fever or increased environmental temperatures, exercise, smoking, stress, pregnancy, pain, medication, glycogen levels, and dehydration

Question 22

what does the left coronary artery branch into?

Answer 22

left anterior descending artery or the interventricular artery

Question 23

what does the right coronary artery branch into?

Answer 23

the right marginal artery and the posterior interventricular artery

Question 24

when is coronary blood supply to the heart the greatest?

Answer 24

during diastole; greatly reduced during systole

Question 25

anastomoses

Answer 25

direct connections between the small branches of the left and right coronary arteries; these have the potential to open up and provide another source of blood to an area

Question 26

cardiac cycle

Answer 26

alternating sequence of systole and diastole

Question 27

what cause heart murmurs?

Answer 27

defective valves that leak or do not completely close

Question 28

apical pulse

Answer 28

a pulse measured at the heart itself and is more certain of HR

Question 29

cardiac output

Answer 29

the volume of blood ejected by a ventricle in one minute; HR x SR

Question 30

stroke volume

Answer 30

the volume pumped from one ventricle in a single contraction

Question 31

cardiac reserve

Answer 31

the ability of the heart to increase output in response to increased demand

Question 32

preload

Answer 32

the mechanical state of the heart at the end of diastole with the ventricles at their maximum volume

Question 33

afterload

Answer 33

the force required to eject blood from the ventricles

Question 34

blood pressure

Answer 34

the pressure of blood against the systemic arterial walls; normal is 120/70 mm Hg; BP = CO x PR

Question 35

what is blood pressure measured in

Answer 35

systolic pressure over diastolic pressure

Question 36

peripheral resistance

Answer 36

the force opposing blood flow or the amount of friction

Question 37

systolic pressure

Answer 37

pressure exerted by the blood when ejected from the left ventricle

Question 38

diastolic pressure

Answer 38

the pressure that is sustained when the ventricles are relaxed

Question 39

pulse pressure

Answer 39

the difference between systolic pressure and diastolic pressure

Question 40

variables affecting blood pressure

Answer 40

blood volume, blood viscosity, venous return, rate and force of contractions, and elasticity of the arteries

Question 41

how does the SNS increase blood pressure?

Answer 41

through acting on beta-adrenergic receptors to increase contraction and by causing vasoconstriction