circulation Flashcards
transport system criteria
suitable carrying medium
pump for moving blood
valves to maintain flow
SOME have vessels and respiratory pigments
insect circulation
open
no respiratory pigment
dorsal tube shaped heart
why do insects have no respiratory pigment
oxygen diffuses directly into tissues
earthworm circulation
closed, single
respiratory pigment, haemoglobin
they have ‘pseudohearts’
fish circulation
closed
single
respiratory pigment/myoglobin
1 atrium one ventricle
mammal circulation
closed
double
haemoglobin, respiratory pigment
2 atria 2 ventricles
closed circulatory system in earthworms
blood is inclosed in blood vessels and tissue fluids exit capillaries
blood moves forward into dorsal vessel and back to ventral vessel
5 pseudohearts pump blood
closed circulatory system advantages
rapid and efficient
-blood flow can be directed by vasoconstriction and vasodilation
-delivers o2 and removes co2 without mixing
open circulatory system in sects
blood is not always held in vessels but circulates through haemocoel which bathes the cells
blood is pumped by the heart directly towards the head by peristalsis and re enters through ostia(insect valves)
haemocoel
body cavity(the space that contains and protects internal organs)
single circulation in fish
blood stays in vessels on a single pathway, passes the heart once
heart->gills->body->heart
insect blood
haemolymph which is in haemocoel
mammals being endothermic means
mammals are endothermic=high metabolic rate= higher need for delivery of o2 and removal of co2
mammals double circulatory system
heart is passed twice
haemoglobin carries o2
high pressure for efficient supply and delivery
BUT is reduced in capillaries of lungs so returnsto heart to pump to rest of body
two circulatory systems
pulmonary
systemic
