transport in animals Flashcards
what is circulation through the lungs called
pulmonary circulation
what is circulation around the rest of the body called
systemic circulation
what is circulatory system
system of blood vessels with a pump and valves to ensure one way flow of blood
advantages of double circulatory system
more efficient in delivering nutrient and oxygen more quickly
control blood pressure so wont damage exchange system
increase pressure of blood flow
separation of oxygen rich and oxygen poor blood
why does valves have strong tendons
prevent valves from turning inside out
what is the use of coronary arteries
supply heart muscle with oxygen and nutrients
how does heart pump
initiated by pacemaker
nerve impulses cause atrium to contract (atrial systole) Av valve open
nerve impulses reaches ventricles and cause ventricle to contract (ventricular systole) semilunar valve open
cardiac muscle relax (ventricular diastole)
how is the pattern of contraction and relaxation of the heart controlled
pace maker
where is pacemaker
right atrium
what does the electrical signals from pacemaker ensure
atria contract before ventricles
heartbeat is fast enough to meet body’s demands
what affects heart rate
blood pressure
oxygen and carbon dioxide level
adrenaline
what causes heart to beat faster
muscle need more energy so contract more often and powerfully
increased respiration rate means more co2 in blood
lower pH and brain detect this and trigger increase in the electrical signals sent by the pacemaker
how to measure heart rate
electrocardiogram, heart sounds and pulse rate
how to treat coronary heart disease
drugs, angioplasty, coronary bypass and heart transplant
how does drug help treat CGD
stations lower blood cholesterol
lower blood pressure
asprin lowers chance of blood clots
describe how angioplasty works
opens up a blocked or narrowed coronary arteries
catheter is threaded through blood vessel in arm up to blocked artery
balloon at end is inflated to push the plaque outwards
stent placed in artery to keep it open
describe coronary bypass
divert flow of blood around the section of blocked coronary artery
piece of blood vessel is removed from another part of body
connect it above and below blocked coronary artery
blood flow in heart muscle improves and chest pain decreases
function of arterioles
receive blood from the arteries
constrict/ dilate to regulate blood flow
function of venules
receive blood from arterioles and connect back to the veins
function of shunt vessels
blood vessel that link artery directly to vein allowing blood to bypass the capillaries in certain areas
control blood flow by vasodilation and vasoconstriction
function of blood
transport, defence and regulation
blood clotting mechanism
tissue damage, platelets arrive at site and form platelet plug
triggers release of clotting factors
cause conversion of prothrombin to thrombin with vit K and calcium ion
causes conversion of fibrinogen to fibrin
fibrin is insoluble plasma protein
forms network of fibres across wound
rbc trapped and forms blood clot, dries in air to from scab
