Blood Vessels And The Heart

Question 1

Right side of the heart

Answer 1

Pumps deoxygenated blood to the lungs
Receives deoxygenated blood from the rest of the body tissues

Question 2

Right side of the heart blood vessels

Answer 2

Pulmonary artery = pumps deoxygenated blood to lungs
Vena cava = takes deoxygenated blood to heart from body tissues

Question 3

Left side of the heart

Answer 3

Pumps oxygenated blood to the rest of the body tissues
Receives oxygenated blood from the lungs

Question 4

Left side of the heart blood vessels

Answer 4

Aorta = pumps oxygenated blood to body tissues
Pulmonary vein = receives oxygenated blood from the lungs

Question 5

Atrioventricular valves

Answer 5

Pointing downwards
Separates atria from ventricles on both sides of the heart
Open when the pressure above is larger than below

Question 6

Semi lunar valve

Answer 6

Separates the ventricles from the pulmonary artery/ aorta (vessels carrying blood away from heart)
Open when pressure below is larger than above

Question 7

Cords

Answer 7

Attach the atrioventricular valves to the ventricles to stop them being forced up into the atria when the ventricles contract

Question 8

What does the blood carry?

Answer 8

Respiratory gases
Products of digestion
Hormones
Metabolic wastes

Question 9

What do arteries do?

Answer 9

Carries blood away from the heart to the rest of the body

Question 10

Arteries structure

Answer 10

Thick muscle layer
Elastic layer
Large overall wall thickness
No valves
Folded endothelium

Question 11

Why do arteries have a thick muscle layer?

Answer 11

Maintain and withstand high pressure flow of blood to tissues because blood travels down a pressure gradient and due to high pressure due to heart

Question 12

Why do arteries have an elastic layer and folded endothelium

Answer 12

To allow for arteries to stretch when blood surges under high pressure (due to heart contracting) then recoil under low pressure

Question 13

Why do arteries not need valves?

Answer 13

Because the pressure is very strong due to contraction thus can only flow in 1 direction

Question 14

What do arterioles do?

Answer 14

Do arteries can divide into smaller vessels then into capillaries to direct blood to flow to different areas of the body in demand

Question 15

Structure of Arteriole

Answer 15

Relatively thinner elastic layer
Relatively thicker smooth muscle layer
More numerous than arteries

Question 16

Why do arterioles have a thicker muscle layer?

Answer 16

To control and direct the blood flow to capillaries in vasoconstriction and vasodilation by contraction and relaxing of the muscle

Question 17

What is the function of capillaries?

Answer 17

To provide an exchange surface between the blood and body cells

Question 18

Structure of a capillary

Answer 18

1 cell thick endothelium
Contains fenestrations
Form capillary beds

Question 19

Why are capillaries composed of 1 cell thick endothelium?

Answer 19

To reduce diffusion distance between blood and tissue vessels

Question 20

Why do capillaries form capillary beds, by being highly branched and very numerous?

Answer 20

For a very large surface area so more exchange can happen at once

Question 21

Why are capillaries very narrow in diameter?

Answer 21

So they can squeeze between tissues making all cells close to the capillary + reduce diffusion distance

Question 22

Why do capillaries have a narrow lumen?

Answer 22

So that red blood cells are closer to body cells to reduce diffusion distance of substances within these cells

Question 23

Why do capillaries have fenestrations?

Answer 23

To form tissue fluid

Question 24

Vein function

Answer 24

To carry blood to the heart under low pressure

Question 25

Structure of heart

Answer 25

Thin muscle wall
Thin elastic wall
Large lumen
Contains valves

Question 26

Why do veins have small elastic layer and muscle layer?

Answer 26

Because the blood is transported slowly under low pressure

Question 27

Why do veins have large lumen?

Answer 27

Causes lower pressure inside

Question 28

Why do veins contain valves?

Answer 28

To prevent back flow of blood because the blood is travelling at low pressures

Question 29

Why does pressure decrease along a blood vessel?

Answer 29

Due to friction

Question 30

What do veins, arterioles and arteries have in common?

Answer 30

Tough fibrous outer layer to resist pressure changes from outside and inside
Thin endothelial lining which are smooth lining cells to reduce friction