Circulatory System Flashcards
What are arteries?
Blood vessels that travel away from the heart.
What are veins?
Blood vessels that travel towards the heart.
What are capillaries?
Blood vessels that directly supply cells with blood.
What are the blood vessels that supply the heart muscle with blood?
Coronary Arteries
How are arteries adapted for their job?
They have a thick outer layer of collagen fibres, and a thick inner layer of muscle and elastin. This means that the walls can withstand the high pressure.
How are veins adapted to their job?
They have thin layers which allow for a larger central lumen. This means that it can carry more blood in one go. It also has valves to stop blood flowing backwards.
What is the Endothelium?
It is the inner wall of the blood vessel.
What is Plasma?
It is the liquid part of the blood. It is mostly water, but it has minerals and other things that the body needs to be supplied with, dissolved in it.
What are Erythrocytes (red blood cells)?
They have haemoglobin in them, which binds to oxygen, allowing them to carry oxygen. They have no nucleus and they are biconcave, in order for them to be able to fit through narrow capillaries.
What are Lymphocytes and Phagocytes (white blood cells)?
These cells protect you from infection. Lymphocytes release antibodies into the blood to bind to the pathogens. They are spherical and have a spherical nucleus. Phagocytes directly devour the pathogens and have lobed nucleuses so they can fit down narrow blood vessels.
What are Platelets?
They are bits of white blood cells that release fibrin when we cut ourselves, causing the blood to stick together and clot.
