Unit 3 - Blood and blood vessels Flashcards
What is plasma?
Liquid component of blood
What is the function of plasma?
Transports dissolved substances e.g glucose, amino acids, mineral ions, hormones, albumin and fibrinogens
What are platelets?
Small fragments of cells
Which is the function of platelets?
Start the process of blood clotting
What is the function of red blood cells?
transporting oxygen and carbon dioxide around the blood
What are the functions of blood as a whole?
-transport of oxygen and carbon dioxide to and from respiring cells
-transport hormones
-transport nitrogenous waste products from cells to excretory organs
-transporting cells and antibodies involved in the immune response
-helps to maintain steady body temperature
-acts as a buffer to minimise pH changes
Why do arteries need to maintain high pressure of the arteries?
So that blood can reach tissues in the body
What is the function of capillaries?
To exchange substances between the blood and tissues
What is the advantage of capillaries being one cell thick?
Gives a short diffusion path
What is the advantage of blood flow being slow through capillaries?
Gives a longer time for the exchange of substances
Why is the blood flow low pressure through capillaries?
Prevents them from bursting
Pressure is spread across many vessels
Why do veins have a wide lumen?
To accommodate the large volume of blood carried
Why are valves present in veins?
Prevent backflow
