Section 5 - Blood and Organs Flashcards
Name the 4 main components of blood (4)
- Plasma - Platelets - Red Blood Cells - White Blood Cells
What is the function of plasma (1)
- Carries everything around the body
What does plasma transport (7)
- Red and white blood cells
- Platelets -
Heat energy - Hormones-
- Urea, from liver to kidneys
- Carbon dioxide, from body cells to the lungs
- Digested food products, gut to all body cells
What are platelets, and how do they help blood clot (4)
- Platelets are small fragments of cells that help blood clot
- Platelets clump together to ‘plug’ the damaged area
- Stops you losing blood, and prevents microorganisms from entering the wound
- Platelets held together by a mesh of a protein, fibrin
What are platelets held together by (1)
- A mesh of protein, fibrin
What do red blood cells do (1)
- Transport oxygen from the lungs to all cells in the body
How are red blood cells adapted to transporting oxygen (3)
- Small and biconcave : large surface area for absorbing and releasing oxygen
- Contain haemoglobin, which contains lots of iron. Reacts in the lungs with oxygen to form oxyhaemoglobin
- Don’t have a nucleas, frees up space for more haemoglobin, so they can carry more oxygen
How does your immune system deal with pathogens (4)
- Pathogens are microorgansisms that cause disease, e.g certain types of bacteria and viruses
- Once pathogens enter your body, they’ll reproduce rapidly unless destroyed.
- Destroying pathogens is the job of your immune system, and white blood cells
- Two types of white blood cell used by the body : phagocytes and lymphocytes
What are pathogens (1)
Pathogens are microorgansisms that cause disease, e.g certain types of bacteria and viruses
What happens once a pathogen gets inside your body (2)
- Reproduces rapidly unless destroyed
- Causing disease
What are phagocytes and what is there job (3)
- Phagocytes detect things that are ‘foriegn’ to the body, e.g pathogens
- They then engulf and digest the pathogens
- They are non specific, they attack anything that’s not meant to be there
What is the job of lymphocytes (5)
- Every pathogen has unique molecules called antigens; on its surface
- When lymphocytes come across foriegn antigens, they produce proteins called antibodies
- Antibodies lock onto invading pathogens and mark them for destruction
- Antibodies produced are specfic to the type of antigen
- Antibodies are produced rapidly and flow round the body, to mark all similar pathogens
How does your body become immune to a disease using lymphocytes (3)
- Lymphoctyes stay in your blood as memory cells after the infection has been fought off
- They reproduce very fast if the same antigen enters the body a second time
- Body becomes immune
How do vaccinations protect from future infections (4)
- By the time your lymphocytes have produced antibodies to deal with a new pathogen, you can get very ill, or die
- To avoid this you get vaccinated against diseases; e.g polio or measles
- Vaccinations inject dead or inactive pathogens into the body; these carry antigens so trigger an immune response, as well as being harmless
- Some lymphocytes remain in the blood as memory cells, so live pathogens will be destroyed by antibodies faster and in greater numbers
What are the three different types of blood vessel, and what do they do (6)
- Arteries : Carry blood away from the heart
- Capillaries : Involved in exchange of materials at the tissues
- Veins : Carry the blood to the heart
What do arteries do and how are they adapted to do this (3)
- Arteries carry blood away from the heart at high pressure
- Artery walls are strong and elastic
- Walls are thick compard to the lumen, containing thick layers of muscle for strength
- Largest atery in the body is the aorta
What do capillaries do and how are they adapted for this (7)
- Involved in the exchange of materials at the tissues
- Arteries branch into capillaries
- Really small
- Carry the blood really close to every cell in the body; to exchange substances
- Permeable walls, allowing substances to diffuse in and out
- Supply food and oxygem. and take away waste, e.g carbon dioxide
- Walls are one cell thick, increases rate of diffusion, by decreasing the distance over which it happens
What do veins do and how are they adapted to do this (6)
- Capilleries eventually join up to form veins
- Blood is at lower prssure, so walls don’t need to be as thick as artery walls
- Bigger lumen, to help blood flow
- Have valves, to keep blood flowing the right direction
- Largest vein in the body is the vena cava
Label A, B and C
A - Artery
B - Capillery
C - Vein
