TRANSPORT IN ANIMALS Flashcards
Why do you need a transport system
single celled organisms (bacteria and amoeba) can obtain nutrients and excrete waste just by simple diffusion
SA:V ratio
single celled organisms have a large SA V
make the diffusion path short
what makes effective transport systems
substances moved in the correct direction
materials move fast enough- supply organism
should have exchange surface toe enable substances to enter and leave blood
have a suitable transport medium( such as blood)
what makes an efficient transport system
two circuits - one to pick up oxygen and one to deliver
system of vessels carry substances where they are needed
what is an open circulatory system
heart that pumps haemolymph (fluid) through short vessels into the haemocoel (cavity)
what happens in the haemocoel ( large cavity)
the haemolymph
bathes organs and tissues enabling diffusion of substances
what happens when the heart relaxes in an open system
the haemolymph blood is sucked back via ostia (pores)
what time of circulatory system do humans have
closed
what is a closed circulatory system
blood is fully enclosed within vessels at all time
from the heart to smaller capillaries
diffusing in and out of the blood and into cells
the returns to heart
what are the two types of closed circulatory system
-single
-double
what is a single system
two chambered heart just once every circuit
what is a double system
four chambered heart
twice every circuit
what are the types of circulation in a double system
systemic
pulomary
what is the systemic ciruclation
what is the pulmonary circulation
