Circulatory System

Question 1

What do all cells require?

Answer 1

the intake of oxygen and nutrients as well as the release of waste products

Question 2

Describe the responsibility of the Circulatory System

Answer 2

it is responsible for transportation of oxygen, nutrients and waste products

Question 3

What are the four main components of the circulatory system?

Answer 3

Arteries

Capillaries

Veins

the Heart

Question 4

Describe the Red Blood Cell

Answer 4

the carrier of oxygen and carbon dioxide

contain hemoglobin, a special protein that uses four iron ions as cofactors to bind oxygen and carbon dioxide

Question 5

Describe the composition of RBCs

Answer 5

they are 1/3rd hemoglobin, which allows for the blood to carry 70x more oxygen

Question 6

Describe Blood Vessels

Answer 6

how blood is circulated through the circulatory system

include : arteries, capillaries and veins

Question 7

Describe Arteries

Answer 7

blood vessels that carry blood away from the heart

they have very thick, strong walls to withstand the pulses of pressure from the heart

they are also very elastic which allows the diameter of the arteries to change

Question 8

Explain Vasodilation

Answer 8

the increase in diameter of a blood vessel, resulting in increased blood flow

Question 9

Explain Vasoconstriction

Answer 9

the decrease in diameter of a blood vessel, resulting in decreased blood flow

Question 10

Describe a Pulse

Answer 10

the cycle of vasodilation and vasoconstriction as the heart pumps into the arteries

Question 11

Describe an Aneurysm

Answer 11

a bulge in the artery wall when the artery walls thin or weaken,

occurs from the pressure of the pulse

Question 12

Explain which arteries carry oxygenated blood

Answer 12

most arteries carry oxygenated blood

one exception is the Pulmonary Artery, which carries deoxygenated blood from the heart to the lungs

Question 13

Describe Capillaries

Answer 13

tiny blood vessels found in the tissue

unlike arteries and veins, capillaries contain no muscle

are often only one-cell thick

Question 14

Explain Nutrient and Gas Exchange

Answer 14

occurs at the capillaries

exchanges between the blood and the cells

mostly exchanged through diffusion, since the capillary walls are so thin that active transport is not necessary

Question 15

Describe Bruising

Answer 15

the dispersal of blood in the tissue due to damaged capillaries

the capillaries walls are very thin and are vulnerable to rupture due to high blood pressure or damage

Question 16

Describe Veins

Answer 16

blood vessels that carry blood towards the heart

*usually from capillaries

due to vasoconstriction in the capillaries, blood pressure/flow is significantly lower in the veins

Question 17

Describe Venous Valves

Answer 17

valves that ensure blood doesn’t move backwards through the veins

muscle contractions help move blood through venous valves, similar to peristalsis

Question 18

Describe Varicose Veins

Answer 18

the pooling of in blood stretched and twisted vessels

when the venous valves become weakened, the blood can flow backwards and pool

usually occurs in the legs

Question 19

Explain why Varicose Veins usually occur in the legs

Answer 19

due to low blood pressure, the muscles must contract harder to move blood

these contractions increase the likelihood of damaging the valves

Question 20

Describe Hemorrhoids

Answer 20

Varicose Veins that occur along the rectum

Question 21

Describe Thermoregulation

Answer 21

the process of maintaining temperature homeostasis in the body

Question 22

Describe how Thermoregulation works

Answer 22

when body temp is high, veins near the body surface expand so that more blood can pass by the surface

blood near the surface exchange heat with the environment, cooling the body

when the environment is cold, veins near the surface constrict so that blood doesn’t lose heat

Question 23

How many blood vessels does the body contain?

(kms)

Answer 23

100,000kms of blood vessels

Question 24

Name the 4 arteries and 3 veins and what they service

Answer 24

pulmonary artery —> services lungs

carotid artery + jugular vein —> services brain

subclavian artery + veins —> services arms

femoral artery + veins —> services legs

Question 25

Describe the Heart

Answer 25

the organ **responsible for pumping blood throughout the circulatory system** contains 4 chambers: 2 atria + 2 ventricles

Question 26

Describe the Septum

Answer 26

**a thick wall of muscle that separates the left atrium and ventricle from the right atrium and ventricle**

Question 27

Describe the Atria

Answer 27

smaller chambers of the heart that receive blood from the body

Question 28

Describe the Ventricles

Answer 28

large chambers of the heart that are extremely muscular they pump blood out of the heart and to the rest of the body

Question 29

Describe the Right Atrium

Answer 29

the location **where the deoxygenated blood enters the heart from the rest of the body** **enters through one of the two vena cava veins**

Question 30

Describe the Superior Vena Cava

Answer 30

the vein that **carries blood that arrives from above the heart** ex- from the jugular or subclavian veins

Question 31

Describe the Inferior Vena Cava

Answer 31

**the vein that carries blood that arrives from below the heart** ex- femoral vein

Question 32

Where does blood go after the Right Atrium?

Answer 32

blood passes **from the Right Atrium to the Right Ventricle through the Right Atrioventricular (AV) Valve** right atrium—> AV—> right ventricle

Question 33

Describe the function of the Atrioventricular (AV) Valves

Answer 33

**to ensure that blood being pushed by the ventricles doesn’t move back into the atria**

Question 34

Where does blood go next after the Right Ventricle?

Answer 34

the blood from the Right Ventricle goes to the Pulmonary Artery

Question 35

Where does blood go after entering the Pulmonary Artery

Answer 35

blood **goes through the Pulmonary Artery into the Lungs to get oxygenated** it then **returns the heart into the left Atrium via the Pulmonary Vein**

Question 36

Where does the blood go after the re-entering the heart into the Left Atrium?

Answer 36

**blood passes through the the Left AV Valve into the Left Ventricle**

Question 37

After the Left Ventricle, where does the blood go?

Answer 37

**the Left Ventricle pumps oxygenated blood through the body via the Aorta, the largest artery**

Question 38

Describe the function of the Semilunar Valves

Answer 38

they **prevent pumped blood from flowing back into the ventricles** **Semilunar Valves are present at both ventricles** *name bc of the shape (crescent moon)

Question 39

Describe Nodes

Answer 39

**how the heartbeat is created** nodes are **two concentrated areas of muscle fibers and nerves**

Question 40

Describe the Sinoatrial (SA) Node

Answer 40

**the SA node receives electrical signals from the brain,** **causing the atria to contract**

Question 41

Describe the Atrioventricular (AV) Node

Answer 41

**the AV Node receives electrical signals from the SA Node, causing the ventricles to contract** **atria contract first**,then the ventricles

Question 42

What are used to map electrical currents during a heartbeat?

Answer 42

Electrocardiograms (ECG)

Question 43

What does the P Wave indicate?

Answer 43

the **P wave** indicates the **concentration of the atria**

Question 44

What does the QRS wave indicate?

Answer 44

the **QRS wave** indicates the contraction of the ventricles

Question 45

Why is the QRS wave so much larger?

Answer 45

the **QRS wave is larger because it needs to pump blood through the whole body** **P waves just need to get blood into the next chamber**

Question 46

What does the T wave indicate?

Answer 46

the **T wave** indicates the **reset of the chambers before the next heartbeat**

Question 47

Describe the Lubb

Answer 47

when **ventricles contract, they push blood into the arteries and push against the AV valves, causing them to *slam* shut** the **slamming of the AV valves** due to the force of blood **produces the first sound of the heartbeat**

Question 48

Describe the Dubb

Answer 48

when the **ventricles relax, the blood that was pumped into the arteries want to return back into the ventricles, *slamming* shut the semilunar valves** the **closing of the semilunar valves** produces the **second sound of the heartbeat**

Question 49

Describe a heart murmur

Answer 49

**when the semilunar or AV valves don’t close properly, allowing some blood to leak through**

Question 50

Describe Diastolic Blood Pressure

Answer 50

the **pressure created from the blood while the heart is at rest** **normally around 80mm Hg**

Question 51

Describe Systolic Blood Pressure

Answer 51

**the pressure produced when ventricles contract** **normally around 120mm Hg**