Answer :
good analogy
blood acts like a
train
when it reaches capillaries
oxygen gets off
carbon dioxide gets on
when you hear homeostasis think
temperature
body stays the same temperature
even if it's cold or hot outside
brain & nervous & body system use
"feedback loops"
when's it's cold
nervous system signals body to
construct blood vessels &
shiver
when it's hot
nervous system signals body to
dilate blood vessels &
sweat
http://www.pathwaymedicine.org/control-of-respiration