specialised transport + circulatory types

What are the different reasons why transport systems are needed

Metabolic demands

Sa:Vr decrease v diffusion distance increases

Amount of SA to absorb/ release gets smaller

Hormones + enzymes needed in another place

Waste products removed from cells + transported to excretory organs

what is open circulatory? what is an example of it?

Few vessels for transportation

EXAMPLE = INSECTS

Haemocoel (open body cavity where blood is pumped from heart and into blood)

direct contact

Returns to heart through open ended vessel

What is the blood of hameooel called?

What does it transport

HAEMOLYMPH

transports food, nitrogen! Waste products

carries no oxygen or carbon dioxide

What is a downside with open circulatory

Can’t meet changing demands

what is closed