Heart Flashcards
how do insects breathe?
through spiracles - to the trachea
why does passive diffusion not work for big animals?
can’t deliver enough oxygen
why do we need a transport system?
nutrients/oxygen
have to loose waste products
need water for diffusion
small artery?
arteriole
small vein?
venule
what kind of cicrculatory system do vertebrates have?
closed
fish heart?
two chambers
low pressure
gills/capillaries in sync
fine for ectotherms
amphibian heart?
three chambers
little mixing of blood
can be directed to skin - good as frogs breathe through skin
reptile heart?
septum divides ventricles
r-l shunt allows blood to by pass lung when submerged
mammal heart cycle?
aorta to body to vena cava to pulmonary artery to lungs to pulmonary vein to aorta
correlation between heart beat and size?
smaller the animal faster the heart beat
how does contraction work?
spontaneously - myogenic property
heart beat initiated at SA node then spreads over atria then ventricle
what are the parts that make up contractipn?
sa node - fastest
atria - fast
ventricle - slow
how does excitement spread?
from sa node to au node then to atria and then ventricle
what is an ECG?
using electrodes on skin to measure electrical current
