animal transport Flashcards
what happens in a closed circulation system?
the blood travels through blood vessels with the impetus being generated by a muscular pump or heart
what happens in an open circulation system?
the ‘blood’ bathes all the cells and organs of the body. It is a feature of all arthropods
what is the blood of insects called?
haemolymph or haemocoel
what is the vascular system of earthworms?
- vascularisation
- closed circulatory system and pumps
- carriage of respiratory gases in blood
what is the vascular system of insects?
- open circulatory system, dorsal tube-shaped heart, lack of respiratory gases in blood
what is the vascular system of fish?
single circulatory system, closed
what is the vascular system of mammals?
double circulatory system, closed
function of arteries
carry blood away from the heart
structure of arteries
- thick walls to resist high blood pressure
- elastic fibres stretch to accommodate blood + elastic recoil pushes blood along the artery
what is the pressure of the arteries like?
high pressure shows a rhythmical rise and fall, corresponding to ventricular systole
what is the structure of the arterioles?
large total surface area + narrow lumen causing reduction in pressure. Smooth muscle tissue can widen or narrow the lumen to in/decrease blood flow
structure of the capillaries
narrow lumen but large total cross-sectional area.
function of capillaries
supply oxygen and nutrients and absorb carbon dioxide and waste.
function of veins
carry blood back to the heart
what is the pressure in the veins like?
low
how is blood returned to the heart through the veins?
by contractions of the skeletal muscle, the vein is squeezed which reduces the volume and increases the pressure inside the vein
- this forces blood through the valve.
what is the function of the valves in the heart?
prevents backflow of blood
- unidirectional flow
