Chapter 8

Question 1

cardiovascular system

Answer 1

the heart and blood vessels. heart provides the power to move the blood and the vascular system represents the network of branching conduit vessels through which the blood flows.

Question 2

arteries

Answer 2

transport blood away from the heart. large, muscular, thick walled. distributes blood to every area of the body

Question 3

3 layers surrounding the lumen

Answer 3

1. thin inner layer, the endothelium: lining of the heart.
2. layer composed primarily of smooth muscle with interwoven elastic connective tissue.
3. outermost layer of large and medium-sized arteries consists of a tough supportive layer of connective tissue, primarily collagen.

Question 4

arterioles

Answer 4

smallest arteries. blood pressure has fallen considerably. regulate blood flow to local regions

Question 5

precapillary sphincter

Answer 5

smooth muscle that serve as gates that control blood flow into individual capillaries

Question 6

vasoconstriction

Answer 6

contraction of vascular smooth muscle. cold day, fingers start to look pale, because vasoconstriction produced by nerves is narrowing your vessels to reduce heat loss from your body

Question 7

vasodilation

Answer 7

relaxation of vascular smooth muscle. hot weather makes skin appear flushed as vasodilation occurs to speed up heat loss and cool you off

Question 8

capillaries

Answer 8

smallest blood vessels. thof a millimeter in diameter-in-walled vessels that average only about one-hundredth. only blood vessels that can exchange materials with the interstitial fluid.

Question 9

capillary beds

Answer 9

extensive networks of capillaries and all over your body

Question 10

lymphatic capillaries

Answer 10

excess plasma fluid is picked up by a system of blind-ended vessels. transport the excess interstitial fluid and other objects to larger lymphatic vessels. removes excess fluid

Question 11

veins

Answer 11

blood flows back to the heart through veins. has 3 layers of tissue. serve as a blood volume reservoir for the entire cardiovascular system. stores most of blood volume

Question 12

3 mechanisms assist the veins in returning blood to the heart

Answer 12

1. contractions of skeletal muscles
2. one-way valves inside the veins
3. movements associated with breathing

Question 13

pericardium

Answer 13

the heart is enclosed in a tough fibrous sac. protects the heart, anchors its surrounding structures and prevents it from overfilling with blood

Question 14

pericardial cavity

Answer 14

contains film of lubricating fluid that allows the heart and the pericardium to glide smoothly against each other when the heart contracts.

Question 15

myocardium

Answer 15

middle layer, this thick layer consisting mainly of cardiac muscle that forms the bulk of the heart

Question 16

pericarditis

Answer 16

inflammation of the pericardium

Question 17

endocarditis

Answer 17

inflamed endocardium

Question 18

atria

Answer 18

two chambers on the top. blood return from body’s tissues enter at right atrium then pass through right ventricle. blood returning from lungs enter left atrium and then passes through 3rd valve into left ventricle.

Question 19

ventricles

Answer 19

two more-muscular bottom chambers. left ventricle is the most muscular of the heart’s 4 cambers cause t must do more work than any other chamber.

Question 20

septum

Answer 20

separates the right and left sides of the heart

Question 21

atrioventricular (AV) valves

Answer 21

located between the atria and their corresponding ventricle prevent blood from flowing back into the atria when the ventricles contract. right Av valve called tricuspid

Question 22

semilunar valves

Answer 22

prevent backflow into the ventricles from the main arteries leaving the heart when the heart relaxes

Question 23

pulmonary circuit

Answer 23

heart pumps blood through the lungs.

1. blood returns to heart from veins, enter right atrium
2. blood passes through the right atrioventricular valve into the right ventricle
3. right ventricle pumpls blood though the pulmonary semilunar vlave into the pulmonary trunk leading to the lungs. pulmonary trunk divides into the right and left pulmonary arteries, supply right and left lungs
4. pulmonary capillaries, blood loses CO2 and receives oxygen.
5. then flows into pulmonary veins leading back to heart. enters the left atrium and flows through the left atrioventricular vlave into left ventrcle

Question 24

systemic circuit

Answer 24

the rest of the body to all the cells simultaneously.

1. left ventricle pumps blood through aoric semilunar valve into aorta
2. travels through branching arteries and arterioles to the capillaries, where it delivers oxygen and nutrients to body tissues and organs and removes waste
3. then blood flows to venules, veins, and back to right atrium

Question 25

aorta

Answer 25

largest artery

Question 26

coronary arteries

Answer 26

branch from the aorta just above the aortic semilunar valve and encircle the heart’s surface.

Question 27

systole

Answer 27

period of contraction. 1. Strial systole - contraction begins with atria. 2. ventricular systole - contraction spreads to ventricles.

Question 28

diastole

Answer 28

period of relaxation. atria and ventricles are relaxed. pulmonary and aortic semilunar valves close preventing backflow of arterial blood

Question 29

cardiac cycle

Answer 29

entire sequence of contraction and relaxation

Question 30

sinoatrial (SA) node

Answer 30

small mass of cardiac muscle cells located near the junction of the right atrium and the superior vena cava. cardiac pacemaker and sets the beat

Question 31

atrioventricular (AV)node

Answer 31

located between the atria and ventricles. slows rate of impluses traveling which gives atria time to contract and empty their blood into ventricles before the ventricle contract. relay impulses

Question 32

atrioventricular (AV) bundle

Answer 32

electrical signal sweeps to a group of conducting fibers in the septum between the 2 ventricles. carry impulses to ventricles

Question 33

purkinje fibers

Answer 33

smaller fibers that carry the impulse to all cells in the myocardium of the ventricles. carry impulses to ventricles.

Question 34

electrocardiogram (ECG or EKG)

Answer 34

record of the electrical impulses in the cardiac conduction system. placing electrodes on the skin at the chest, wrists, and ankles. 3 formations:

1. p wave - across atria
2. qrs complex - septum and 2 ventricles
3. t wave - end of electrical activity in ventricles

Question 35

blood pressure

Answer 35

the force that blood exerts on the wall of a blood vessel as a result of the pumping action of the heart

Question 36

systolic pressure

Answer 36

highest pressure: its reached during ventricular systole when the ventricles contract to eject blood fro the heart

Question 37

diastolic pressure

Answer 37

lowest pressure: occurs during ventricular diastole when the ventricles relax.

Question 38

hypertension

Answer 38

blood pressure higher than normal, the silent killer

Question 39

hypotension

Answer 39

blood pressure too low

Question 40

baroreceptors

Answer 40

regulate arterial blood pressure. located in the carotid arteries and aorta. pg. 176

Question 41

cardiac output

Answer 41

amount of blood that the heart pumps into the aorta each minute

Question 42

heart attack

Answer 42

sudden death of an area of heart tissue due to no oxygen starvatin

Question 43

heart wall consists of 3 layers

Answer 43

1. epicardium - outermost layer, thin layer of epithelial and connective tissue
2. myocardium
3. endocardium - innermost layer, layer of endothelium continuous with the endothelium lining blood vessels.