section 5: blood and organs Flashcards
list the four main components of the blood
- plasma
- platelets
- red blood cells
- white blood cells
What part of the blood is liquid?
Plasma
What does plasma carry?
- red and white blood cells
- platelets
- digested food products eg glucose, amino acids
- carbon dioxide
- urea
- hormones
- heat energy
What helps blood to clot? Why?
Platelets
- prevent microorganisms from entering the wound (infection)
- prevents blood loss
What, apart from platelets, does the blood need to clot?
- fibrin (a mesh of protein)
- clotting factors (also proteins)
how are RBCs adapted?
- BICONCAVE shape -> Large SA
- small
- haemoglobin -> contains iron
- no nucleus -> more space = more oxygen
What do haemoglobin and oxygen form?
Oxyhaemoglobin
What are pathogens?
Disease causing microorganisms
What do phagocytes do?
- detect pathogens and anything foreign
- ENGULF AND DIGEST them
- non specific - attack anything not usually there
What do lymphocytes do?
- pathogens have ANTIGENS (unique molecules) on surface
- lymphocytes make ANTIBODIES that lock onto & mark the pathogen to be destroyed by other WBCs. These are produced rapidly.
- the antibodies are specific to that type of antigen - will ignore other types
- memory cells are then produced
Expkein the process of vaccination
- involved injecting a person with dead or inactive pathogens
- carry antigens so still trigger an immune response and therefore antibodies
- makes memory cells
Why are memory cells important? (More for vaccinations tbh)
- reduce time it takes to make antibodies, so you are less likely to get really ill or die eg polio or measles
The three blood vessels are?
- arteries
- capillaries
- veins
Arteries carry the blood..?
Away
Veins carry the blood?
To the heart
For the purpose of Capillaries carry the blood..?
In the exchange of materials at the tissues
Arteries carry blood at what pressure
HIGH
What enables the arteries to carry blood under pressure?
- strong and elastic artery walls
- elastic fibres allow arteries to EXPAND
- walls are THICK with layers of muscle compared to the lumen
What is the lumen
The hole in the middle of the blood vessel
What is the purpose of valves?
to prevent the backflow of blood
What is the largest artery in the body?
The aorta