Functions of the Blood Flashcards
What are the four main components of blood?
- Plasma
- Platelets
- Red Blood Cells
- White Blood Cells
What is plasma?
Pale yellow liquid which carries everything needed to transport around body
Made of mainly water
What does plasma carry?
- Red and white blood cells, and platelets
- Digested food products - from gut to body cells
- CO2 - from body cells to lungs
- Urea - from liver to kidneys
- Hormones
- Heat energy
What do red blood cells do?
carry oxygen from lungs to all around the body
How are red blood cells adapted to carry oxygen?
- They are Biconcave - to give large surface area for absorbing and releasing oxygen
- They contain haemoglobin
- They do not have a nucleus - frees up space for more haemoglobin, so can carry more oxygen
Name two types of white blood cell
Phagocytes
Lymphocytes
What are pathogens?
Micro-organisms that cause disease
What do phagocytes do?
Engulf pathogens and digest them
What do pathogens have on their surface?
unique molecules called antigens
What do lymphocytes produce when they detect a foreign antigen?
Produce proteins called antibodies
These lock on to invading pathogens and mark them out for destruction by other white blood cells
Some lymphocytes stay around in the blood as…
memory cells - can reproduce very quickly if same antigen enters body a second time
What are the three types of blood vessel?
Arteries
Capillaries
Veins
What do arteries do?
carry blood AWAY from the heart
What do capillaries do?
-involved in the exchange of materials at the tissues
carry the blood really close to every cell in the body to exchange substances with them
What do veins do?
carry blood TO heart
Why are artery walls strong and elastic?
Because the heart pumps out blood at a high pressure
What is the largest arty in the body?
The aorta
How big are capillaries?
Really small
Why do capillaries have permeable walls?
So substances can diffuse in and out
What do capillaries supply and take away?
- supply food and oxygen
- take away wastes i.e CO2
How thick are capillaries walls?
one cell thick - increases rate of diffusion
What do capillaries join ip to form?
veins
Why aren’t the vein walls as thick as artery walls?
The blood is at a lower pressure
What do veins have to keep the blood flowing in the right direction?
valves
What is the largest vein in the human body?
The vena cava
What does the right atrium of the heart receive?
deoxygenated blood (through the vena cava)
After deoxygenated blood moves through the right atrium where does it go?
To the right ventricle, which pumps it to the lungs via the pulmonary artery
What does the left atrium of the heart receive?
oxygenated blood from the lungs (through the pulmonary vein)