the heart Flashcards
what does an open circulatory system mean
the blood is not always held within the blood vessels and can circulate through the body cavity (so cells are immersed directly in the blood)
how do insects pump blood towards the head
peristalsis
state 3 features of an open circulatory system
- little control over direction of circulation
- no respiratory pigment (insect blood doesn’t contain oxygen)
- blood pumped at low pressure into fluid filled cavity (haemocoel)
what is a fluid filled cavity called (open circulatory system in insects)
haemocoel
what does a closed circulatory system mean
the blood is enclosed within the blood vessels and tissues are not in direct contact with the blood (separate fluid exits capillaries and bathes the cells – tissue fluid)
what are 3 advantages of closed circulatory systems
- the blood flow is more rapid and efficient
- blood flow can be directed where needed by vasoconstriction/dilation
- more efficient delivery of oxygen and nutrients and removal of waste products
whats the separate fluid that bathes the cells called in closed circulatory systems
tissue fluid
why can closed circulatory systems pump blood at a higher pressure
the tissues are not in contact with the blood and the tissues are bathed in tissue fluid
what does a single closed circulatory system mean
the blood stays in vessels on a single pathway around the body, blood only passes through the heart once before returning to the gills
describe the route blood takes through a single closed circulatory system in fish
heart–>gills–>body–>heart
what does a double circulation system mean
the heart pumps the blood and it goes twice through the heart
why do mammals need double circulatory systems
they are endothermic (produce their own body heat), so have high metabolic rate and high energy requirement – cells need large amount of glucose and oxygen and removal of waste products
what are the 2 components of the double circulatory system
pulmonary circulatory system, systemic circulatory system
explain the route of blood in the pulmonary circulatory system
heart–>lungs–>heart
explain the route of blood through the systemic circulatory system
heart–>body–>heart
4 advantages of double circulatory system
- heart increases pressure after passing through lungs= blood flows quicker to body tissues
- more efficient delivery of oxygen and nutrients to body tissues
- oxygen supply to heart muscles is better
- systemic circulation can carry blood at higher pressure than pulmonary
features of the mammalian heart
4 chambered pump, double pump working synchronously keeping oxygenated and deoxygenated blood separated, cardiac muscle (myogenic) beats from within the muscle itself
