Circulatory System Part 2 Flashcards
What are the four main components of blood?
Red blood cells, white blood cells, platelets and plasma
How many litres of blood do humans contain and what percentage of our body weight is it?
4-5 litres of blood, making up 8% of our body weight
What are red blood cells and what is their main role?
A biconcave disk that is round and flat without a nucleus, contains haemoglobin which is a molecule specially designed to hold oxygen and carry it to cells
What are the two main types of white blood cells?
Lymphocytes and macrophages
What is the role of lymphocytes?
To fight disease by making antibodies
What is the role of macrophages?
To eat and digest micro-organisms
What are platelets and what is their main role?
Bits of cell broken off larger cells and they are activated to form a clot when they encounter collagen as a result of a break in the blood vessel
What is plasma and what does is its main role?
Plasma makes up around 65% of blood volume, and is a straw-coloured liquid which carries the cells and platelets
How is cardiac output calculated?
Stroke volume multiplied by heart rate
What is stroke volume?
The amount of blood the left ventricle pumps out per beat
What is heart rate?
The number of beats the heart takes per minute
How is maximum heart rate of a person calculated?
220 minus age
