The heart

Question 1

what membrane surrounds the heart

Answer 1

the pericardium

Question 2

how many chambers are in the heart

Answer 2

4

Question 3

what are the different chambers in the heart

Answer 3

• right atrium
• left atrium
• right ventricle
• left ventricle

Question 4

what are the different veins in the heart

Answer 4

• inferior vena cava
• superior vena cava
• pulmonary vein

Question 5

what are the different arteries in the heart

Answer 5

• pulmonary arteries

- aorta

Question 6

what are the different valves in the heart

Answer 6

semilunar valves between ventricles and arteries

atrioventricular valves between atria and ventricles

Tricuspid valve - right side
bicuspid valve - left side

Question 7

what do arteries do

Answer 7

carry blood away from the heart

Question 8

what do veins do

Answer 8

carry blood towards the heart

Question 9

what do capillaries do

Answer 9

tiny vessels that carry blood between cells. Where the transported substances actually enter and leave the blood.

Question 10

describe in detail what veins do

Answer 10

Veins carry blood from every tissue in the body to the heart.

As the pressure is so much lower in the veins than in the arteries, there is little need for elastic fibres and smooth muscle in the walls.

Question 11

what do veins have

Answer 11

semi lunar valves to stop blood flowing backwards

Question 12

why does the exchange of material not take place in the arteries and veins

Answer 12

Because their walls are too thick and too impermeable

Question 13

describe the structure of capillaries

Answer 13

very narrow and thin-walled and compose of endothelium and are single-celled. Is often highly permeable, because its very thin and has holes between cells in some capillaries

Question 14

because there is a large number of capillaries what does this help with

Answer 14

there is a number of capillaries and have a huge surface area to volume ratio, helping rapid diffusion of substances between blood and cells.

Question 15

what is the arrangement of capillaries called

Answer 15

capillary beds

Question 16

what is double circulation

Answer 16

The first loop travels from the right side of the heart through the lungs to gain oxygen.

The second loop travels from the left side of the heart around the body to lose oxygen and gain carbon dioxide.

Question 17

what are antigens

Answer 17

Antigens are proteins found on the outside of the cells.

Question 18

what are antibodies

Answer 18

antibodies are produced by B cells in response to a specific antigen.

Question 19

what is the cardiac cycle

Answer 19

The cardiac cycle is the sequence of events that occurs in one complete heart beat

Question 20

what is the pumping phase of the cardiac cycle

Answer 20

systole

Question 21

what is the relaxing phase of the cardiac cycle

Answer 21

diatole

Question 22

what are the 3 stages of the cardiac cycle

Answer 22

• atrial systole
• ventricular systole
• diastole

Question 23

what is atrial systole

Answer 23

The Atria contract, and ventricles relax forcing blood into the ventricles

Question 24

what is ventricular systole

Answer 24

The ventricles contract forcing blood out of ventricle into arteries and the atria relax and fill with blood

Question 25

what is diastole

Answer 25

Is when both atria and ventricles relax

Question 26

what is stroke volume

Answer 26

is the volume of blood forced from a ventricle of the heart with each contraction.

Question 27

what is cardiac output

Answer 27

is the amount of blood leaving one of the ventricles every minute.

Question 28

how do you calculate cardiac output

Answer 28

stroke volume x heart rate

Question 29

how is blood flow altered

Answer 29

by altering the diameter of blood vessels

Question 30

describe how blood vessels alter there diameter

Answer 30

- arteries stretch to accommodate extra blood flow - Smooth muscle in arteries contracts to reduce diameter which reduces blood flow. - Smooth muscle in arteries relax to increase diameter which increases blood flow.

Question 31

can veins change their dimateretrer

Answer 31

no

Question 32

do arteries have valves

Answer 32

no

Question 33

do veins have valves

Answer 33

yes

Question 34

what type of walls do arteries have

Answer 34

thick, muscular, elastic walls

Question 35

what type of walls do veins have

Answer 35

have thin, inelastic walls with little muscle

Question 36

what is the difference between the left and right sides of the heart

Answer 36

The left ventricle is much thicker and muscular compared to the right ventricle which is thinner and less muscular because it has to pump blood all around the body