gas exchange and immunity Flashcards
cardiovascular system is made of
heart, tubes, and blood
pulmonary circuit
blood is pumped to LUNGS by RIGHT side of heart
systematic circuit
blood is pumped throughout BODY by LEFT side of the heart
4 chambers in the heart
left/right ventricle; left/right atrium
ventricle functions:
contracts to put blood out of heart
blood enters ventricle from
atria
which chamber does blood enter first?
atria
atria function
absorb blood while ventricle is contracting; top off ventricle to increase efficiency
size: ventricle vs atria
ventricle is larger
4 valves of the heart
right/left atrioventricular valve ; left/right semilunar valves
atrioventricular valve functions
one way valve that allows blood into the ventricle but NOT the atrium
where is the atrioventricular valve located?
between atrium and ventricle
where is the semilunar valve located?
between ventricle and artery
semilunar valve function
one way valve that prevents blood from rushing back into ventricle
what creates the electrical signal of the heart rhythm?
the sinoatrial node wall of right atrium
atrioventricular node function
delays electrical signal so the atrium can contract and empty before the ventricle contracts
___ slows heart
parasympathetic NS
___ speeds heart up
sympathetic NS
what makes blood pass without friction?
endothelium (smooth epithelium) lining
capillary exchange:
???
artery carries blood
away from heart
vein carries blood
back to heart
blood pressure can be thought of as
“gas” for getting places
where is blood pressure measured?
the arteries
blood pressure is highest as
ventricle contracts
Systolic pressure:
forces blood into arteries and stretches them
Diastolic pressure:
some blood from last contraction has been pushed into capillaries
about how many miles worth of capillaries are there in a human?
60,000 miles
how much blood fills the 60,000 miles of capillaries?
5-10%
precapillary sphincters can allow blood to…
flow where it is needed most
respiratory system is designed to obtain oxygen by
extracting it from environment and distributing it to cells (via gills, trachea, lungs)
mammals: lungs exchange oxygen with
air
lungs are made of
microscope sacs called alveoli
how many alveoli per lung?
480 million