(P2)Heart And Circulatory System Flashcards
List the 4 parts of the blood, and describe what they do
Plasma (liquid part): carries blood cells through the blood vessels, contains dissolved substances
White blood cells: attacks pathogens and produces antibodies
Red blood cells: carries oxygen
Platelets: cause blood to clot when blood vessel has been damaged to prevent pathogens from entering blood
Describe how red blood cells are adapted to their function
Large surface area (due to biconcave disc shape) for diffusion of oxygen.
No nucleus - more room for haemoglobin to carry oxygen
Describe the role of arteries, capillaries and veins (all types of blood vessels)
Arteries carry blood away from heart. All arteries except pulmonary arteries carry oxygenated blood to body.
Veins carry blood to heart. All veins except for pulmonary veins carry deoxygenated blood from body back to heart.
Capillaries exchange materials such as oxygen , glucose and CO2 with body tissues
How are veins adapted to their function?
Veins have valves to stop blood flowing backwards.
The left side of the heart pumps oxygenated blood around the body. List the 4 parts on the left side, and describe what two of them do
Left atrium, left ventricle, aorta (carries oxygenated blood from heart to body) and pulmonary vein (brings oxygenated blood from lungs to heart)
Describe blood circulation from the atria back to the heart.
Blood enters the atria, which contracts to to force the blood into the ventricles, which contract to force the blood into the arteries. Blood flows through the arteries to the organs and returns to the heart through the veins
The right side of the heart pumps deoxygenated blood to the lungs and back. List the 4 parts on the right side, and describe what two of them do
Right atrium, right ventricle, pulmonary artery (carries deoxygenated blood from heart to lungs) and the vena cava (carries deoxygenated blood from body to heart
Describe the role of the AV valves and tendons (heart strings)
AV valves prevent blood flowing backwards (backflow). Heart strings stop valves turning inside out
Why is the left ventricle muscle wall thicker than that of the right ventricle?
The right ventricle only pumps blood to the lungs, whereas the left ventricle pumps blood around the whole body, so it requires a greater force
What do alveoli in the lungs do?
Create a large surface area for diffusion of gases into capillaries
Capillaries are one cell thick, minimising diffusion distance
