Types of circulatory systems

Created by

Ceri

Cards (10)

open circulatory system 
blood is not always enclosed in vessels all of the time
blood can flow freely through the body cavity
some invertebrates (e.g. insects)
closed circulatory system 
vessels containing a transport medium
single or double
vertebrates
single circulatory system  
blood passes through the heart once for each complete circuit of the body
double circulatory system 
blood passes through the heart twice for each complete circuit of the body
open circulatory system 
low pressure
transports food, nitrogenous waste and other things
direct exchange between between transport medium and tissue cells
slow, little control over direction of flow
flow cannot be varied to meet demands when there is change
closed circulatory system 
high pressure
transports CO2, O2, food, nitrogenous waste and other things
diffusion through walls of blood vessels to exchange with tissue cells
blood flow can be altered by narrowing or widening of blood vessels
allows steeper gradient for diffusion to be maintained
single circulatory system 
found in fish
one blood pressure that is lower
heart has two chambers and no septum
less efficient - one pump, pressure decreases as it passes through the gills
double circulatory system
found in mammals
lower pulmonary pressure
higher systemic pressure
heart has four chambers
more efficient - differential pressure, 1 pump for each section of circuit
single circulatory system 
heart -> gill -> body -> heart
double circulatory system 
body in separate loop to lungs
pulmonary circuit has low pressure to assist in gas exchange
allows rapid delivery of oxygen and nutrients to respiring tissues