circulatory system

Question 1

functions of circulatory system

Answer 1

1. transports gases, nutrient molecules, hormones and waste materials
2. regulates internal temperature and transports hormones (homeostasis)
3. protects against blood loss from injury and against disease

Question 2

major components of circulatory system

Answer 2

heart, blood vessels, and blood

Question 3

three main types of blood vessels

Answer 3

arteries, veins, and capillaries

Question 4

arteries

Answer 4

carry blood away from the heart (usually oxygen rich), relaxes and contracts as blood surges from the heart

Question 5

capillaries

Answer 5

tiny vessels where gases, nutrients, and wastes are exchanged as capillaries are permeable

Question 6

veins

Answer 6

carry blood to the heart (usually oxygen poor)

Question 7

structure of an artery

Answer 7

have thick, muscular, elastic walls that maintain blood pressure between pump cycles

Question 8

externa

Answer 8

tough, outer connective tissue

Question 9

media

Answer 9

thick layer of smooth muscle and elastin fibers

Question 10

intima

Answer 10

smooth endothelium forming the lining of the lumen

Question 11

aneurysm

Answer 11

inner wall of artery bulges outward putting pressure on outer wall (genetic)

Question 12

arterioles

Answer 12

small arteries that relax and contract when flow changes

Question 13

aneurysm

Answer 13

inner wall of artery bulges outward putting pressure on outer wall (genetic)

Question 14

vasoconstriction

Answer 14

nervous system causes arterioles to contract in times of emergency which increases blood pressure to certain parts of the blood while restricting it to others

Question 15

vasodilation

Answer 15

nervous system causes arterioles to relax (blushing)

Question 16

atherosclerosis

Answer 16

fat droplets block flow of blood and can lead to heart disease

Question 17

treatment of atherosclerosis

Answer 17

bypass surgery or angioplasty

Question 18

veins

Answer 18

thinner walls with a larger inner circumference, not muscular or elastic, cannot contract like arteries but can dilate to become very wide

Question 19

veins have one way valves

Answer 19

needed to prevent blood from flowing backwards (no pressure)

Question 20

blood is moved through veins by

Answer 20

contraction and relaxation of skeletal muscles around vein

Question 21

stretching

Answer 21

increases blood flow which has a massaging effect

Question 22

vericose veins

Answer 22

pooling and back pressure of blood causes damage to surrounding tissues. valves misfunction and venules burst because of age obesity, poor nutrition and posture

Question 23

capillaries are tiny

Answer 23

only one cell thick and wide enough for a single blood cell to fit it through

Question 24

bruise

Answer 24

capillaries get damaged and blood/plasma rushes into interstitial spaces

Question 25

capillaries nutrients

Answer 25

oxygen, monosaccharides, amino acids, fatty acids, and hormones

Question 26

functions of the heart

Answer 26

1. pumps blood to lungs (pulmonary circulation) and to body (systemic circulation) 2. keeping oxygen rich and oxygen poor blood separated 3. ensuring blood only flows in one direction

Question 27

waste products

Answer 27

CO2, Urea, Ammonia

Question 28

the heart walls

Answer 28

made of cardiac muscle

Question 29

the heart has valves so

Answer 29

blood only flows one way

Question 30

contractions of heart

Answer 30

rhythmic and involuntary

Question 31

the heart has four chambers

Answer 31

``` 2 atria (top) - collectors that are filled with blood returning to heart 2 ventricles (bottom) - pumps that send blood back out of heart ```

Question 32

the heart needs

Answer 32

its own supply of O2 and nutrients

Question 33

the coronary artery

Answer 33

supplies the heart with O2 and nutrients. This small artery, if blocked by fats, leads to heart disease

Question 34

atria

Answer 34

chambers that fill with blood returning to the heart either from the lungs (left) or from the body (right)

Question 35

ventricles

Answer 35

chambers that receive blood from the atria and pump it either to the lungs (right ventricle) or the body (left ventricle)

Question 36

septum

Answer 36

muscular wall that separates the left and right sides of the heart

Question 37

superior vena cava

Answer 37

collects deoxygenated blood from the head, chest, and arms

Question 38

inferior vena cava

Answer 38

collects deoxygenated blood from central and lower body

Question 39

vena cava

Answer 39

combine and dump blood into the right atrium

Question 40

pulmonary arteries

Answer 40

the blood vessels that carry the blood form the right ventricles to the lungs

Question 41

pulmonary veins

Answer 41

blood vessels that carry blood back from the lungs to the left atrium

Question 42

aorta

Answer 42

the largest blood vessels in the body that leaves the left ventricle carrying oxygenated blood to the body

Question 43

tricuspid valve

Answer 43

the atrioventricular valve that has three flaps and separates the right atrium from the right ventricle

Question 44

bicuspid valve

Answer 44

the atrioventricular valve that has two flaps and separates the left atrium from the left ventricle

Question 45

semilunar valves

Answer 45

half-mooned in shape, these valves are found both in the pulmonary trunk and the aorta