Chapter 42.2

Question 1

What does the mammalian cardiovascular system do?

Answer 1

meets the body’s continuous demand for O2

Question 2

Where does blood begin to flow?

Answer 2

the right ventricle pumping blood into the lungs via the pulmonary arteries

Question 3

What happens in the lungs?

Answer 3

the blood loads O2 and unloads CO2

Question 4

What happens to oxygen-rich blood from the lungs?

Answer 4

enters the heart at the left atrium via the pulmonary veins

Question 5

Where is blood pumped through the aorta to?

Answer 5

the body tissues by the left ventricle

Question 6

What does the aorta do?

Answer 6

provides blood to the heart through the hcoronary arteries

Question 7

How does blood return to the heart?

Answer 7

through the superior vena vaca and inferior vena cava

Question 8

superior vena cava

Answer 8

blood from head, neck, and forelimbs

Question 9

inferior vena cava

Answer 9

blood from trunk and hind limbs

Question 10

What do the superior vena cava and inferior vena cava flow into?

Answer 10

the right atrium

Question 11

What do the two atria have and serve as?

Answer 11

relatively thin walls; collection chambers for blood returning to the heart

Question 12

What do the ventricles have and do?

Answer 12

thicker walls; contract much more forcefully

Question 13

The cardiac cycle

Answer 13

the rhythmic cycle where the heart contracts and relaxes

Question 14

systole

Answer 14

the contraction, or pumping phase, of the heart

Question 15

Diastole

Answer 15

the relaxation, or filling, phase of the heart

Question 16

Heart rate (pulse)

Answer 16

the number of beats per minute

Question 17

Stroke volume

Answer 17

the amount of blood pumped in a single contraction

Question 18

cardiac output

Answer 18

the volume of blood pumped into the systemic circulation per minute

Question 19

what does the cardiac output depend on

Answer 19

both the heart rate and the stroke volume

Question 20

Four valves prevent backflow of blood in the heart

Answer 20

1. the atrioventricular (AV) valves

2. semilunar valves

Question 21

Atrioventricular (AV) valves

Answer 21

separate each atrium and ventricle

Question 22

Semilunar valves

Answer 22

control blood flow to the aorta and the pulmonary artery

Question 23

What causes the “lub-dup” sound of a heart beat?

Answer 23

the recoil of blood against the AV valves (lub) then against the semilunar (dup) valves

Question 24

What causes heart murmur

Answer 24

backflow of blood through a defective valve

Question 25

some cardiac muscle cells are…

Answer 25

autorhythmic

Question 26

autorhythmic

Answer 26

they contract without any signal from the nervous system

Question 27

the sinoatrial (SA) node (pacemaker)

Answer 27

sets the rate and timing at which cardiac muscle cells contract

Question 28

How can impulses that travel during the cardiac cycle be recorded

Answer 28

as an electrocardiogram (ECG or EKG)

Question 29

Where do impulses from the SA node travel to?

Answer 29

the atrioventricular (AV) node

Question 30

What happens at the AV node?

Answer 30

the impulses are delayed and then travel to the Purkinje fibers that make the ventricles contract

Question 31

the pacemaker is regulated by two portions of the nervous system:

Answer 31

the sympathetic and parasympathetic divisions

Question 32

what does teh sympathetic division do

Answer 32

speeds up the pacemaker

Question 33

what does the parasympathetic division do

Answer 33

slows down the pacemaker

Question 34

what is the pacemaker also regulated by

Answer 34

bormones and temperature