mammalian heart

Question 1

Diffusion is fast enough for

Answer 1

transport over short distances

Question 2

larger distances requires a…..

Answer 2

The efficient supply of materials over larger distances requires a mass transport system.

Question 3

small organism can

Answer 3

exchange materials directly from the surface of the body.

Question 4

what does increasing size causes

Answer 4

, the surface area to volume ratio to decrease

to a point where the needs of the organism cannot be met by the body surface alone

Question 5

what do transport systems do

Answer 5

To take materials from cells to exchange surfaces and from exchange surfaces
to cells.

Materials have to be transported between exchange surfaces and the environment.

They also need to be transported between
different parts of the organism.

Question 6

what do larger organism need to get nutrients and respiratory gases to the cells

Answer 6

). Specialist exchange surfaces are
therefore required to absorb nutrients and respiratory gases, and
remove excretory products.

Question 7

where are exchange surfaces located ?

Answer 7

These exchange surfaces are located in specific regions of the organism.

Question 8

what increases the needs for an organism to have specialised structures for mass transports

Answer 8

the surface area to volume ratio,

• how active the organism is.

Question 9

4 required factors for increasing exchange rates

Answer 9

A suitable medium

• A form of mass transport
• A closed system of tubular vessels

A mechanism

Question 10

A suitable medium

Answer 10

A suitable medium in which to carry materials,
This is normally a liquid based on water because water readily
dissolves substances and can be moved around easily,

gases such as air breathed in and out of the lungs.

Question 11

• A form of mass transport

Answer 11

• A form of mass transport in which the transport medium is moved
around in bulk over large distances - more rapid than diffusion.

Question 12

• A closed system

Answer 12

• A closed system of tubular vessels that contains the transport
medium and forms a branching network to distribute it to all parts
of the organism.

Question 13

• A mechanism

Answer 13

• A mechanism for moving the transport medium within vessels.
This requires a pressure difference be tween one part of the system
and another.

Question 14

mechanism in animals

Answer 14

Animals use muscular contraction.

Either from body muscles or specialist pumping organs such as the heart.

Question 15

plant mechanism

Answer 15

Plants rely on natural, passive processes such as the evaporation of water

Question 16

valves mechanism

Answer 16

maintains the mass flow movement in one

direction,

Question 17

intercostal muscles and diaphragm in breathing

Answer 17

• A mechanism for the mass flow of water or gases, for example,

Question 18

closed double circulatory system

Answer 18

closed -
blood is confined in organs such as heart and in vessels

double- blood passes through the heart twice.

Question 19

why does the blood passes through the heart twice

Answer 19

the heart pumps deoxygenated and nutrient lacking blookd to the lungs. The lungs oxygenate the blood. The blood is at a low pressure. this low pressure would cause the circulation rate to be too slow. The blood passes through the heart which increases pressure and speeds up circulation rate.

Question 20

since mammals have high temperatures the must have

Answer 20

high metabolism

Question 21

kidney

Answer 21

renal artery

renal veins

Question 22

body exchange surfaces

Answer 22

body
vena cava
right atrium 
right ventricles
pulmonary arteries
lungs
pulmonary veins
left atrium 
left ventricle
aorta 
body

Question 23

the heart

Answer 23

two closely associated pumps the left pump deals with oxygenated blood from lungs the right deals with deoxygenated blood from the body

Question 24

atrium

Answer 24

thin-walled and elastic and stretches as it collects

blood.

Question 25

ventricles

Answer 25

thicker muscular wall that contracts strongly to pump blood some distance, either to the
lungs or to the rest of the body.

Question 26

the aorta

Answer 26

The aorta is connected to the left ventricle and carries oxygenated
blood to all pans or the body except the lungs.

•
•

Question 27

The pulmonary vein

Answer 27

The pulmonary vein is connected to the left atrium and brings oxygenated blood back from the lungs. Unusually for a vein, it carries oxygenated blood.

Question 28

pulmonary artery

Answer 28

The pulmonary artery is connected to the right ventricle and carries deoxygenated blood to the lungs. where its oxygen is replenished and its carbon dioxide is removed. Unusually for an artery, it carries deoxygenated blood.

Question 29

vena cava

Answer 29

• The vena cava is connected to the right atrium and brings deoxygenated blood back from the tissues of the body

Question 30

the hearts blood vessels are called

Answer 30

coronary arteries, which branch off the aorta shortly after it leaves the heart.

Question 31

heart blockage of arteries

Answer 31

leads to myocardial infarction. or heart attack, because an area
of the heart muscle is deprived of blood and therefore oxygen also. The
muscle cells in this region are unable to respire (aerobically) and so die.