5 - Blood and Organs Flashcards
What are the four main components in blood?
Plasma
Platelets
Red Blood Cells
White Blood Cells
What is plasma?
A pale yellow liquid that carries everything that needs transporting around the body
e. g.
- Red and white blood cells and platelets
- Digested food products from the gut to body cells
- CO2 from the body cells to the lungs
- Urea from the liver to kidneys
- Hormones (acting as chemical messengers)
- Heat energy
What are platelets?
Small fragments of cells that help blood clot
- When you damage a blood vessel platelets clump together to ‘plug’ the hole
- Known as blood clotting which stops too much blood being lost and microorganisms entering the wound
What holds protein together?
The platelets are held together by a protein called fibrin
What is the function of Red Blood Cells?
Transport oxygen from the lungs to all the cells in the body
What are some adaptations for Red Blood Cells?
- Biconcave shape to give a large surface area for absorbing and releasing oxygen
- Contain haemoglobin (which gives blood its colour) which contains lots of iron
- No nucleus so there is more space for haemoglobin and oxygen
What does haemoglobin do?
- Gives blood its colour
- Contains lots of iron
In the lungs - reacts with oxygen to become oxyhaemoglobin
In body tissues - reverse reaction to release oxygen to the cells
What does haemoglobin do?
- Gives blood its colour
- Contains lots of iron
In the lungs - reacts with oxygen to become oxyhaemoglobin
In body tissues - reverse reaction to release oxygen to the cells
What is the role of the immune system?
Deals with pathogens to make the body healthy
What is the role of phagocytes?
- Detect things that are ‘foreign’ to the body
- Engulf the pathogens and digest them
- Are non-specific so will attack anything that is not meant to be there
What is the role of lymphocytes?
- When they come across a foreign antigen they will produce proteins called antibodies
- Antibodies lock onto the invading pathogens and mark them for destruction by other white blood cells
- Specific so only attack one type of antigen
- Some are kept as memory cells (making you more immune to the disease)
What are pathogens?
- Microorganisms that cause disease
- Once in the body they will reproduce rapidly unless stopped and destroyed
- They have antigens on their surface
How do vaccinations protect from disease?
- A dead or inactive pathogen is injected into the body
- The harmless antigens are detected by the lymphocytes and the body produces antibodies to fight the antigens
- Some antibodies are kept as memory cells
- If the real disease were to attack the body there would already by antibodies to fight it off quickly
How do vaccinations protect from disease?
- A dead or inactive pathogen is injected into the body
- The harmless antigens are detected by the lymphocytes and the body produces antibodies to fight the antigens
- Some antibodies are kept as memory cells
- If the real disease were to attack the body there would already by antibodies to fight it off quickly
What are the three types of blood vessels?
- Arteries
- Capillaries
- Veins
What is role of arteries?
- Carries blood away from the heart
- Blood is pumped at high pressure (it has to go all around the body) so the walls are strong and elastic
- Thick walls compared to the lumen because they contain a lot of muscle
- The largest artery is the aorta
- Branch into capillaries
What is the role of capillaries?
- Involved in exchange of materials at the tissue
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What is the role of capillaries?
- Involved in exchange of materials at the tissue
- Really tiny and carry blood very close to every cell in the body to exchange substances
- Permeable walls for things to diffuse in and out
- Supply food and oxygen and take away waste like CO2
- Walls only one cell thick which increases the rate of diffusion by decreasing the distance to travel
- Nucleus in the small wall and small lumen
- Join up to form veins
