8.1 Transport Systems In Multicellular Organisms

Question 1

what do circulatory systems carry around the body

Answer 1

gases such as oxygen and carbon dioxide
nutrients
waste products
hormones

Question 2

what are common features of a circulatory system

Answer 2

a liquid transport medium that circulates around the system eg blood
vessels that carry the transport medium
a pumping mechanism to move fluid around the system

Question 3

what an open body cavity called

Answer 3

haemocael

Question 4

what’s an open circulatory system

Answer 4

a system where very few vessels contain the transport medium and its pumped straight from the heart to the animals body cavity the transport medium comes into direct contact with the tissues and cells and this is where exchange takes place

Question 5

what pressure is the transport medium under in an open circulatory system

Answer 5

low pressure

Question 6

how does exchange occur in open circulatory systems

Answer 6

in the open body cavity the transport medium comes into direct contact with the tissues and cells and this is where exchange occurs

Question 7

through what vessel does the transport medium return to the heart in, in an open circulatory system

Answer 7

and open ended vessel

Question 8

what’s insect blood called

Answer 8

haemolymph

Question 9

what animals typically have open circulatory systems

Answer 9

invertebrates and insects

Question 10

what does insect blood transport in open circulatory systems

Answer 10

nitrogenous waste products, food and the cells involved in defence against disease
but not co2 or o2

Question 11

where does gas exchange take place in insects

Answer 11

the tracheal system

Question 12

what’s insects body cavity and heart like

Answer 12

spilt by a membrane and the heart extends along the length of the thorax and abdomen

Question 13

what’s the disadvantage of open circulatory system in insects

Answer 13

the haemolymph circulates but a steep conc gradient can’t be maintained for efficient diffusion and the amount of haemolymph flowing to a particular tissue cannot be varied to meet changing demands

Question 14

what’s a closed circulatory system like

Answer 14

here the blood doesn’t come directly into contact with the body cells the heart pumps the blood around quickly and under high pressure and the blood returns directly to the heart substance leave and enter blood by diffusion through vessel walls

Question 15

what pressure is the blood in a closed circulatory system under

Answer 15

relatively high pressure

Question 16

how are substances exchanged in a closed circulatory system

Answer 16

substances leave and enter blood by diffusion through the walls of the blood vessels

Question 17

how can the amount of blood flowing to particular tissues in a closed circulatory system be controlled

Answer 17

by narrowing or widening the blood vessels

Question 18

in which animals are closed circulatory systems found

Answer 18

fish and all mammals

Question 19

why are specialised transport systems needed

Answer 19

high metabolic demands ( need lots of O2 and produce lots of waste products)

small sa:v ratio this means diffusion distances are bigger and sa to remove substances gets smaller

molecules or hormones may be made in one’s place but needed in another

waste products need to be removed from cells and transported to excretory organs

food will be digested in one organ system but needs to be transported to every other cells for use in respiration/other

Question 20

what are single closed circulatory systems

Answer 20

where the blood flows through the heart and is pumped out to travel all around the body where it passes through two sets of capillaries before returning to the heart so the blood only travels through the heart once for each complete blood circulation

Question 21

what happens each time the blood passes through set of capillaries in a single closed circulatory system

Answer 21

the first time oxygen and carbon dioxide are exchanged and the second set of capillaries are in the different organ system and substances are exchanged between the blood and cells

Question 22

what happens to the blood pressure and the blood passes through the two sets of capillaries

Answer 22

as a result of passing through these two sets of very narrow vessels the blood pressure in the system drops considerably so the blood returns to the heart quite slowly

Question 23

how efficient are single closed circulatory systems and why and what is the exception

Answer 23

not very efficient as the blood returns to the heart slowly after passing through the capillaries and activity of animals with this system tends to be quite slow

fish are an exception due to countercurrent system

Question 24

how does fishes countercurrent system allow for an effective circulatory system

Answer 24

it allows them to take lots of O2 from the water and their body weight is supported by water and they don’t have to maintain their body temp so this reduces their metabolic demand

Question 25

what are double closed circulatory systems and who has them

Answer 25

birds and most mammals have them as they are very active and have to maintain their own body temp the double system involves two separate circulations

1 the blood is pumped from the heart to the lungs to pick us oxygen and unload carbon dioxide then returns to the heart

2 blood flows through the heart and is pumped out to travel all around the body before returning to the heart again

Question 26

summary of double closed circulatory system

Answer 26

the blood travels twice through the heart for each circuit of the body (lungs and then other organs) and each circuit only passes through one capillary network which means relatively high pressure and so fast flow of blood can be maintained

Question 27

what’s the circulation to the lungs called in DCCS

Answer 27

pulmonary circulation

Question 28

what’s the circulation to the other organs called in DCCS

Answer 28

systematic circulation

Question 29

why are double closed circulatory system effective

Answer 29

in each circuit the blood travels through it only passes through one capillary network not two which means it has a relatively high pressure and a fast blood flow can be maintained