Transport in animals Flashcards
Describe the circulatory system
a system of blood vessels with a pump and valves to ensure
one-way flow of blood
Describe the single circulation of a fish
fish have a TWO chambered heart
meaning that for every 1 circuit of the body, the blood passes through through the heart ONCE
What does it mean to have a double circulation?
just means that for every circuit, the blood passes through the heart TWICE
Describe the double circulation of a mammal
mammals have a FOUR chamber heart
meaning that for every circuit, blood passes through the heart TWICE
Explain the advantages of a double circulation
oxygenated blood is separated from the deoxygenated blood which ensures a more efficient supply of oxygenated blood to body tissue
a double circulation can also increase the pressure of the blood after it has passed through the lungs= a systematic circulation carries blood at higher pressure than the pulmonary circulation, this therefore then allows for more rapid circulation of blood to body tissues
name structures of the mammalian heart
muscular wall
septum
left and right ventricles
left and right atria
one-way valves
coronary arteries
What does it mean to have a single circulation
means that for every circuit, blood passes through the heart ONCE
Explain the relative thickness of the muscle walls of the left and right ventricles
LEFT
thicker muscle wall as it has to plump blood at a high pressure around the entire body
RIGHT
has a less thick muscle wall as it has to plump wall at a lower pressure to the lungs
Explain the relative thickness of the muscle walls of the atria compared to those of the ventricles
the ventricles have thicker muscular walls than the atria
this is because blood is pumped out at a greater pressure from these chambers compared to the atria
Explain the importance of the septum in
separating oxygenated and deoxygenated blood
muscle wall that separates deoxygenated and oxygenated blood, preventing mixture
Describe the functioning of the heart
the contraction of muscles of the atria and
ventricles and the action of the valves
what type of blood vessel pumps away blood from the heart
arteries
What blood vessel returns blood to the heart?
veins
Why does the heart rate increase during exercise?
so that sufficient blood is taken o the working muscles to provide them with enough oxygen and nutrients for the increased respiration
describe the effect of physical activity on the heart rate
Following continuous exercise, the heart begins to beat at a faster rate for a while to ensure that all excess waste products are removed from the muscle cells
increased exercise- increased heart rate, it can take up to several minutes until exercise has come to an end to get back to normal bmp
Explain how coronary arteries are affected and the effect of this on the heart.
They have a build up of fatty deposits on the walls of the arteries which reduces the lumen inside the artery causing them to reduce the blood flow to the heart which basically means that less oxygenated blood is supplied to the heart= making the heart work less efficiently.
Describe coronary heart disease
the blockage of coronary arteries due to coronary arteries having fatty build-up in the walls causing them to have reduced lumen space for oxygenated blood to reach the heart which causes blood flow to be restricted and as less oxygen can reach the heart muscle, this can therefore this can result in a heart attack.
Discuss the roles of diet and exercise in reducing
the risk of coronary heart disease
A poor diet, excess of fatty food intakes and poor exercise habits can cause the augmentation of Cholesterol LDL that puts those with that type of cholesterol at high risk of CHD as the fatty build-up in the walls are more likely to happen in the arteries
Describe the structure of arteries
Relative thickness of wall- thick muscular walls containing elastic fibres
diameter of lumen- quite narrow
Speed of flow- fast
Describe the structure of veins
Relative thickness of wall- thin
diameter of lumen- large
Has valves for one -way blood flow
Describe the structure of capillaries
Relative thickness of wall- one cell thick
diameter of lumen- very small lumen