7.3 + 7.4

Question 1

Why large organisms have specialised transport system

Answer 1

With increasing size, SA : vol ratio decreases and the more active the organism is

Greater need for specialises system with pump so nutrient and respiratory gases can be absorbed

Question 2

7 Features of transport system

Answer 2

1. suitable medium in which to carry materials e.g. blood
2. form of mass transport in which transport medium is moved around in bulk over large distances
3. closed system of tubular vessels that contains transport medium and forms branching network to distribute all around the organisms
4. mechanism for moving transport medium within vessels(pressure difference via muscular contraction or passive processes)
5. mechanism to maintain mass flow of movement in one direction
6. means of controlling flow of transport medium to suit changing needs of different parts
7. mechanism for mass flow of water or gases

Question 3

Circulatory system in mammal

Answer 3

closed, double system
blood is confined to vessels and passed twice through heart for each complete circuit

Question 4

Double circulatory system description

Answer 4

When blood is passed through lungs, pressure is reduced.
Forces blood to return to heart to boost its pressure before being circulated to rest of tissues
Allows substances to be delivered quickly- necessary because mammals have high body temp and high metabolism rate

Question 5

right ventricle

Answer 5

pumps blood only to the lungs
has thinner muscular wall

Question 6

left ventricle

Answer 6

thick muscular wall
contracts to create enough pressure to pump blood to rest of body

Question 7

aorta

Answer 7

connected to left ventricle
carries oxygenated blood to all parts of the body except lungs

Question 8

vena cava

Answer 8

connected to right atrium
brings deoxygenated blood back from the tissues of the body(except lungs)

Question 9

pulmonary artery

Answer 9

connected to right ventricle
carries deoxygenated blood to the lungs
oxygen is replenished
carbon dioxide is removed

Question 10

pulmonary vein

Answer 10

connected to left atrium
brings oxygenated blood back from the lungs

Question 11

supplying heart muscle with oxygen

Answer 11

supplied by own vessels- coronary arteries
branch off the aorta shortly after leaves heart

Question 12

myocardial infraction(heart attack)

Answer 12

blockage of coronary arteries
area of heart muscle is deprived of blood and o2 so die