immune system

Question 1

primary defences

Answer 1

• skin: dermis and epidermis

- mucous membrane

Question 2

what is the mucus membrane

Answer 2

protects the non-skin covered area

• cells produce and secrete a lining of sticky mucous witch traps pathogens and prevents infection
• often found with cilia

Question 3

what are clotting proteins

Answer 3

• prothrombin
• fibrogen

they block cuts at the site of injury to prevent entry of pathogens and continous bleeding

Question 4

what happens when you get a cut

Answer 4

1. damaged blood cells release chemicals that stimulate platelets to group at that area
2. platelets and damaged tissue release clotting factor
3. clotting factor chemicals convert prothrombin into thrombin (an active enzyme)
4. thrombin catalyzes conversion of soluble fibrogin into insoluble fibrin/fibrin

Question 5

secondary defences

Answer 5

when a pathogen enters the body;

1. primary immune response; first encounter with particular pathogen
2. secondary immune respose; quicker and more intense; immunity (not the first encounter)

Question 6

phagocyte

Answer 6

white blood cells are called leucocytes

• macrophage; can change cellular shape to surround invading cell by phagocytosis
• NO REAL IMMUNITY AS ITS RANDOM
• 1. macrophage encounters cells and determines whether it is a natural ‘self cell’ or a ‘not self cell’
     
     2. macrophage engulfs ‘not self cell’ and lyosomes chemically digest them

Question 7

lymphocyte

Answer 7

a plasma white blood cell that produces antibodies by recognizing specific bacteria by their antigen

-each lymphocyte is specific to a pathogen

antibodies; y-shaped protein moleucles produced in response to a specific pathogen; has a binding site to attach to the bacteria antigen

Question 8

primary immune response

Answer 8

1. a specific antigen type is identified
2. a specific plasma cell is identified that can produce an antibody to bind to the antigen
3. the specific plasma cell clones itself to increase amount
4. army of plasma cells being antibody production
5. antibodies find their antigen match and eliminate the pathogen
6. some plasma cells remain in bloodstream and provide immunity incase of a second infection
7. these ‘memory cells’ respond quickly if the same antigen is encountered again by self-replicating (SECONDARY IMMUNE RESPONSE)

Question 9

HIV

Answer 9

human immunodeficiency virus

• infects lymphocytes and therefore causes drop in them and their antibody production
• it becomes aids (acquired immune deficiency syndrome) when person loses immune response capability

transmitted by;

• unprotected sex
• unclean needles
• pregnancy, labour, delivery and breastfeeding
• blood transfusion

Question 10

antibiotics

Answer 10

combat bacterial infections by blocking bacteria’s metabolisms or processes (e.g.g cell wall production)

• no effect on virsues; only target prokaryotic effect with not effect on eukaryotic cells

Question 11

bacterial ressistance

Answer 11

• bacteria divide quickly therefore can quickly mutate
• genetic variation
• resistant bacteria can rapidly repopulate colonies
• longterm and overuse of antibiotics
• in response, variations of antibiotics exist