Module 4.3 - Physiology of the Cardiovascular System

Question 1

What controls the blood flow through the heart?

Answer 1

the 4 heart valves

Question 2

How/What is the general flow of blood through the heart?

Answer 2

One direction from the vessels into the atria, into the ventricles, then back into the vessels

Question 3

Why is the heart considered a double-pump?

Answer 3

it has 2 circuits, a right and left

Question 4

pulmonary circuit

Answer 4

the right circuit, sends deoxygenated blood to the lungs to be oxygenated

Question 5

systemic circuit

Answer 5

the left circuit, sends oxygenated blood to the cells of the body

Question 6

inferior and superior vena cavae

Answer 6

2 large veins that return deoxygenated blood to the right atrium

Question 7

What valve does blood pass through going from right atrium to right ventricle?

Answer 7

tricuspid valve

Question 8

Where does the right ventricle pump the blood?

Answer 8

through the pulmonary valve and into the pulmonary arteries

Question 9

pulmonary arteries

Answer 9

bring blood from heart to lungs, the only arteries in body that carry deoxygenated blood

Question 10

What happens to the blood inside the lungs?

Answer 10

blood is oxygenated in the capillary beds of lungs (also loses its CO2)

Question 11

pulmonary veins

Answer 11

carry blood from lungs back to heart through left atrium

Question 12

What valve does blood pass through going from the left atrium to the left ventricle?

Answer 12

bicuspid (mitral) valve

Question 13

Where does the left ventricle pump the blood?

Answer 13

through the aortic valve into the aorta, then aortic trunk

Question 14

aortic arch

Answer 14

from aorta, turns posteriorly carry oxygenated blood to supply the cells of the body’s tissues with oxygen and nutrients

Question 15

What completes the circuit of blood flow?

Answer 15

deoxygenated blood returns back to heart through vena cavae

Question 16

About how many times does the heart beat per minute?

Answer 16

70 times

Question 17

About how long does a heart beat last?

Answer 17

0.85 seconds

Question 18

systole

Answer 18

refers to the contraction of heart chambers

Question 19

diastole

Answer 19

refers to relaxation of heart chambers

Question 20

describe the cardiac cycle

Answer 20

aka the heart beat, is a cyclical pattern consisting of 3 general phases

Question 21

describe the 1st phase of the cardiac cycle

Answer 21

the atria contract for about 0.15 seconds while the ventricles relax

Question 22

describe the 2nd phase of the cardiac cycle

Answer 22

the ventricles contract for about 0.3 seconds while the atria relax

Question 23

describe the 3rd phase of the cardiac cycle

Answer 23

both the atria and ventricles relax for about 0.4 seconds

Question 24

Why do the atria have a shorter systole?

Answer 24

they only send blood a short distance into the ventricles, while the ventricles pump blood through the much larger pulmonary and systemic circulatory circuits

Question 25

What events do the "lub-dub" sounds mark?

Answer 25

the lub sound is the atrioventricular valves closing and the dub sound is the semilunar valves closing

Question 26

What tool can be used to hear the heart sounds?

Answer 26

stethoscope

Question 27

systolic pressure

Answer 27

results from the blood being forced into the arteries during ventricular systole

Question 28

diastolic pressure

Answer 28

pressure in the arteries during ventricular diastole

Question 29

what piece of equipment measures blood pressure

Answer 29

sphygmomanometer

Question 30

What does blood pressure measure?

Answer 30

the amount of pressure required to stop the flow of blood through an artery, typically the brachial artery

Question 31

Describe how the 4 different components of a sphygmomanometer fuction.

Answer 31

The bladder filled with airis held in place over artery by the cuff and filled with air by squeezing the bulb.The manometer displays the pressure in mm Hg. The pressure inside the bladder is slowly released by turning the valve

Question 32

How is the stethoscope used to read blood pressure?

Answer 32

used to listen to 1st and last sounds of blood flow displayed on manometer

Question 33

What 2 numbers does a blood pressure reading consist of?

Answer 33

a systolic (top number) and a diastolic (bottom number)

Question 34

What maintains the heart's intrinsic rythmic abilities?

Answer 34

its elaborate electrical system

Question 35

How do we know that the heart is somewhat dependent of any nerve supply from the CNS?

Answer 35

the contractions of the cardiac muscle begin within the heart muscle itself and it can continue to beat outside of the body with proper nutrients and oxygen

Question 36

How do the nervous and endocrine system regulate the heart rate? What else do these systems effect?

Answer 36

through neurotransmitters such as norepinephrine and acetylcholine. The interaction of the nervous and endocrine systems enables the heart to change blood pressure with emotional and physical stressors.

Question 37

Where does the electrical impulse that controls the cardiac cycle begin?

Answer 37

the SA Node (sinoatrial node) aka the pacemaker, found in the right atrium

Question 38

Describe the SA node

Answer 38

a small mass of specialized cardiac muscle that contains both cardiac and nervous tissue characteristics

Question 39

What path does the electrical impulse of the cardiac cycle take after the SA node?

Answer 39

spreads through the atria, creating left and right atrial systole, then travels through the AV node (atrioventricular node or AV bundle) into the bundle of His. Next, to the ventricular apex (downward point of the heart). Finally, the Purkinje fibers, causing the left and right ventricles to contract

Question 40

What is an ECG (EKG)?

Answer 40

electrocardiogram, device used to measure electrical impulses in the heart

Question 41

What do ECG traces represent and what are they used for?

Answer 41

the rythmic electrical impulses and corresponding mechanical events in the heart. to monitor and diagnose patient conditions

Question 42

P wave

Answer 42

denoted as Atrial depolarization (active firing of a nerve impulse) and atrial systole

Question 43

QRS complex

Answer 43

denoted as Ventricular depolarization and ventricular systol

Question 44

T wave

Answer 44

denoted as Ventricular repolarization (returning to rest) and ventricular diastole

Question 45

Why is there no way to note the repolarization of the atria?

Answer 45

its activity is lost within the QRS complex