B4 Organising animals and plants Flashcards
what is the problem with a single circulatory system?
the blood looses lots of pressure so when it reaches the organs, it cannot deliver much oxygen
what is the advantage of a double circulatory system?
because the blood passes through the heart twice, the blood travels to the cells rapidly and delivers the oxygen needed
what is the function of the heart?
to pump blood around the body
what key structures are there in the heart? (aside from blood vessles)
the atria - top
ventricles - bottom
valves - separate the atria and ventricles
what are the 4 chambers of the heart and what do they transport?
vena cava - brings deoxygenated blood to the heart
pulmonary artery - transports blood from the heart to the lungs
pulmonary vein - transports blood from the lungs to the heart
aorta - transports blood from the heart to the rest of the body
what do the valves in the heart do?
prevent blood flowing backwards into the atria when the ventricles contract
why is the left side of the heart wall thicker?
they blood from the left side of the heart needs to travel around the entire body. this means the muscular wall needs to exert a greater force on the blood so it is at a higher pressure.
what are the coronary arteries?
arteries which branch out from the aorta into the heart muscle. they provide oxygenated blood to the muscle cells of the heart. the oxygen is used for respiration to provide energy for contraction
what is the pacemaker?
a group of cells in the right atrium which controls the natural resting heart rate
what do arteries carry?
very high pressure blood from the heart to the organs
what is the structure of an artery?
thick muscular wall - withstands high pressure blood
elastic fibres - stretches when a surge of blood passes through and recoils in between surges
what are capilliaries?
blood vessels which transport blood to the cells.
what are the adaptations of capilliaries?
very thin walls - diffusion path is short
what do veins transport?
deoxygenated blood back to the heart from the body
what is the issue with blood travelling in veins?
the blood is travelling slowly at low pressure so could stop or flow backwards
what are the adaptations of veins?
thin wall - pressure is low so a thick wall is not needed
large lumen - allows for a lot of blood to travel
valves - prevent backflow
what are the components of blood?
plasma
white blood cells
red blood cells
platelets
what is the function of blood plasma?
it transports:
- soluble products of digestion
- carbon dioxide
- urea
what is the function of red blood cells?
to transport oxygen from the lungs to the cells
what are the adaptations of red blood cells?
haemoglobin - carries oxygen by turning it into oxyhaemoglobin
no nucleus - can carry more haemoglobin
biconcave disc - greater surface area so more oxygen can diffuse in and out rapidly
what are white blood cells part of?
the immune system
what are the features of a white blood cell?
contains a nucleus - this means it has DNA which encodes the instructions needed for the cell to do its job
what are platelets?
tiny fragments of cells which help the blood clot
what are the uses for donated blood in medicine?
to replace blood lost during injury
extracting platelets to help blood clot
extracting proteins
what are some issues with using donated blood?
the blood has to be the same blood type or the patient could die
diseases can be transmitted in the blood
what are cardiovascular diseases?
diseases of the heart and blood vessels
they are non-communicable