Lecture Fifteen- Friday, February 5 , 2010h
know what’s in the textbook for test: Sections A-E of Chapter 12 (pgs 359-425)
Functions of the Cardiovascular System: TRANSPORT
Bringing oxygen from cells to lungs
Bringing fuel to cells (eg glucose from liver to brain)
Bringing nutrients to the body (eg from intestine to the liver)
Removal of waste products (eg Carbon dioxide to lungs, ammonia to
liverureakidneys) Waste products are toxic!
Circulation of hormones (eg adrenaline to skeletal muscles)
Circulation of immune cells and antibodies
Regulation of electrolytes
Regulation of pH
Water balance, osmoregulation
Thermoregulation (transport heat from where it’s produced to skin, where
it can be released) frostbite: flow of blood to the skin shut down to keep
heat in the body
Who doesn’t need a Cargiovascular System?
Ameoba! (~300 microns across)
no heart or vessels, doesn’t need them due to small size
if they get hungry, pseudopods engulf
in they need oxygen, it diffuses in from water surrounding it
wastes are diffused out as well
Single cell of a rabbit ventricle is about 100 microns long. Cardiovascular system has
millions of them. Therefore the scale of the cell is almost the same as the scale of
the amoeba. Therefore any organism big enough has cardiovascular system. see
Diffusion: The spontaneous movement of particles caused by random thermal
see picture of diffusion fro heart to lung to heart: Chain of events: convection to bring molecule into alveolus, then diffusion, then
convection in cardiovascular system (lungs to body part), then diffusion out.
[Partial pressure of oxygen in mitochondria very low]
Fick’s Law: Shows you what flow will be, in essence.
-The wall of the alveolus is very thin to make diffusion easier.
-Edema: coating of water in the alveolus. Now an oxygen molecule must diffuse
through water and then the wall, therefore flux is decreased. If it is very severe you
Pump = heart
Pipes = vessels
Fluid = blood
Kardia: heart; vas: vessel
The Insect Heart:
Has a long vessel that runs along the ba