Structure Of The Cardiovascular System

Question 1

How does the blood circulate?

Answer 1

From the heart through the arteries to the capillaries to the veins and back to the heart

Question 2

What happens as blood moves away from the heart?

Answer 2

There is a drop in blood pressure

Question 3

What is the endothelium lining the central lumen of blood vessels surrounded by?

Answer 3

Layers of tissue

Question 4

Arteries carry blood______________

Answer 4

Away from the heart

Question 5

What do arteries have an outer layer of ?

Answer 5

Connective tissue containing elastic fibres

Question 6

What does the middle layer of arteries contain?

Answer 6

Smooth muscle with more elastic fibres

Question 7

What do the elastic walls of the arteries do after each contraction of the heart?

Answer 7

Stretch and recoil to accommodate the surge of blood

Question 8

What does contraction and relaxation of the smooth muscle in the walls of arterioles (small arteries) cause?

Answer 8

Vasoconstriction or vasodilation to control blood flow

Question 9

What happens to arterioles leading to working muscles during strenuous exercise ?

Answer 9

They vasodilate which increases blood flow

Question 10

What happens to arterioles leading to abdominal organs during strenuous exercise?

Answer 10

They vasocontract which reduces blood flow

Question 11

How is blood transported from arterioles to venules (small veins) ?

Answer 11

It is passed through a dense network of capillaries

Question 12

What do capillaries allow?

Answer 12

The exchange of substances with tissues

Question 13

Size of capillaries?

Answer 13

One cell thick, so allows quick and efficient exchange of materials

Question 14

Veins carry blood___________

Answer 14

Towards the heart

Question 15

What do veins have an outer layer of ?

Answer 15

Connective tissue containing elastic fibres

Question 16

Veins have a much thinner ____________ than arteries

Answer 16

Muscular wall

Question 17

Blood flows along veins at a ___________ pressure that arteries

Answer 17

Lower

Question 18

The ________ of a vein is wider than that of an artery

Answer 18

Lumen

Question 19

What are present in veins to prevent the back flow of blood ?

Answer 19

Valves

Question 20

What supplies oxygenated blood to the heart muscle ?

Answer 20

Coronary arteries

Question 21

What supplies oxygenated blood to the brain?

Answer 21

Carotid artery

Question 22

What supplies oxygenated blood to the kidneys ?

Answer 22

Renal artery

Question 23

What supplies oxygenated blood to the liver?

Answer 23

Hepatic artery

Question 24

What vein carries deoxygenated blood from the brain to the heart?

Answer 24

Jugular vein

Question 25

What vein carries deoxygenated blood from the liver to the heart?

Answer 25

Hepatic vein

Question 26

What vein carries blood from the gut to the liver ?

Answer 26

Hepatic portal vein

Question 27

What vein carries deoxygenated blood from the kidney to the heart ?

Answer 27

Renal vein

Question 28

How is blood carries to the tissues ?

Answer 28

In thick walled arteries

Question 29

What happens when thick walled arteries enter an organ ?

Answer 29

They divide into many arterioles which agin divide into capillaries

Question 30

What does blood pressure force out of the capillaries into the tissue fluid and what does it leave behind ?

Answer 30

Forces out plasma , with small soluble molecules Leaves behind the blood cells with large plasma protein molecules

Question 31

What do the cells exchange by diffusion down concentration gradients ?

Answer 31

Molecules with the tissue fluid

Question 32

What useful molecules diffuse into cells?

Answer 32

Food and oxygen

Question 33

What diffuses out of cells?

Answer 33

Carbon dioxide and waste

Question 34

At the venule end of the capillary Bed what enters the capillaries by osmosis and what causes a water concentration gradient?

Answer 34

Tissue fluid Blood cells and plasma proteins

Question 35

What do capillaries merge together to form in order to carry blood back to the heart ?

Answer 35

Venules which again merge to form veins

Question 36

On balance blood pressure forces more ______ out of the capillaries than diffuses back by _______

Answer 36

Water Osmosis

Question 37

Where is excess tissue fluid collected?

Answer 37

In lymph vessels which have thin walls and valves f

Question 38

How is lymph returned to the blood then the heart?

Answer 38

By skeletal muscles squeezing it past the next valve