organisation - the heart and circulation Flashcards
what type of circulatory system does fish have?
single - blood looses pressure before reaching organs so moves slowly not giving a lot of oxygen
what type of circulatory system do humans have?
double
heart to the lungs back to the heart then organs then back to the heart. travels rapidly providing oxygen needed
what is the heart?
an organ consisting of mainly muscle tissue that pumps blood around body
how many chambers does heart have and what are their names?
4; right atrium, left atrium, right ventricle, left ventricle
how are the atrias separated?
by valves
what does the vena cava, pulmonary vein, pulmonary artery and aorta do in movement of blood do?
vena cava brings deoxygenated blood from the body. blood then passes from heart to lungs in the pulmonary vein. in lungs blood collects oxygen. oxygenated blood passes from the lungs to the heart in the pulmonary vein. then pumped from heart tot he body through aorta
what is the pattern of blood flow through the heart?
blood first enters left atrium and right atrium. atria now contract and blood forced into the ventricles. ventricles now contract forcing blood out of the heart.
function of valves
stop blood from flowing backwards into the atria when the ventricles contract
which side of the heart has a thicker muscular wall and why?
left because left ventricle pumps blood around entire body so needs to provide a greater force whereas right only pumps blood to the lungs
where are coronary arteries found?
branch out of the aorta and spread into the heart muscle
what is the purpose of the coronary arteries?
provide oxygen to the muscle cells of the heart. oxygen then used in respiration to provide energy for contraction
what is natural heart rate controlled by?
pacemaker cells in the right atrium
what is used if natural pacemakers don’t work properly?
plant an artificial pacemaker
what is an artificial pacemaker?
a small electrical device and it corrects heart irregularities in the heart rate
