Circulatory System Flashcards
Define a double circulatory system
blood passes through the heart twice and has two different circuits
what is the function of valves
to prevent backflow of blood
where are pacemakers found
right atrium
what are pacemakers
small electrical impulses which regulate the rate of contraction
the order of bloodflow through the heart:
vena cava, right atrium, right ventrical, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta
coronary arteries
encircle the heart to ensure that muscle cells get all nutrients and oxygen needed
arteries carry blood…
away from the heart
veins carry blood…
towards the heart
capillaries exchange…
nutrients and oxygen with tissues
arteries have thick layers of muscle/elastic tissue in order to…
deal with the high pressure blood which flows through them
arteries have a small lumen so that…
high blood pressure is maintained
capillaries take away…
waste products like CO2
capillaries are one cell thick and permeable in order to…
allow for the diffusion of substances into and out of the capillaries to cells
the cross sectional area of capillaries is huge in order to…
allow bloodflow to run slower and give capillaries more time to exchange substances
veins have large lumens and thin walls because…
blood is low pressure
veins have valves in order to…
prevent the backflow of blood
rate of blood flow =
ammount of blood/time
blood is made up of…
red blood cells, white blood cells, platelets and plasma
red blood cells carry oxygen to cells for…
cellular respiration
haemoglobin combines with oxygen to become…
oxyhaemoglobin
oxyhaemoglobin splits back into…
oxygen and haemoglogin when it reaches the cells
red blood cells have no nucles in order to…
have more space for oxygen and haemoglobin
oxygen has a large surface area because it is shaped like a…
biconclave disk
white blood cells engulf and destroy: this is called…
phagocytosis
what do antibodies do?
bind onto pathogens and help destroy them
what do antitoxins do?
neutralise toxins that antigens produce
what do platelets do and how is it helpful?
act as glue when cuts occur (clotting) - stops infection from microorganisms
plasma makes blood watery so it can…
flow
what does plasma carry
red and white blood cells + platelets; glucose, amino acids; waste products (CO2);hormones, proteins
blood replacement is necessary because…
wounds can mean there is not enough blood to deliver oxygen and nutrients to tissues
artificial blood adds…
volume but doesnt contain red blood cells
blood transfusions have actual red blood cells which contain…
necessary composites like oxygen and nutrients for cellular respiration
