Chapter 11 Immunity

Question 1

Physical barrier to infection

Answer 1

▪️Skin which is a tough physical barrier consisting of keratin
▪️stomach acid(HCL) which kills bacteria
▪️gut and skin flora - natural bacterial flora completes with pathogens for food and space

Question 2

Phagocytosis

Answer 2

▪️Process in which phagocytes engulf pathogens thus destroying them by fusing a pathogen such as bacteria enclosed ina phagocutic vacuole with a lysosome
▪️ nuetrophils and macrophages ; both made in bone marrow

Question 3

Antigens

Answer 3

▪️After the pathogen is engulfed and destroyed its chemical markers called antigens are then presented on the surface of the phagocyte.
▪️ the phagocyte then becomes an antigen presenting call which activates other types of immune system , immune response will be stimulated if the antigen is reconginised as foreign

Question 4

Specific immune response

Answer 4

Specific immune response is antigen specific and produces responses specific to one type of pathogen only .

It relies on lymphocytes produces in the bone marrow

Question 5

B cells
And
T cells

Answer 5

▪️ B cells Mature in bone marrow and are involved in humoral response
▪️T cells move from bone marrow to the thymus gland where they mature , they are involved in cell mediated response

Question 6

Memory cells

Answer 6

Cells which replicate themselves when exposed to an invading pathogen
Remains in lymph nodes searching for the same antigen this resulting in a much faster immmune response .
Allows long term immunity

Question 7

B effector

Answer 7

Anti body producing cells
When the correct antibody is produced to fit the pathogen ,the antibody divides by mitosis in order to multiply so that the infection can be prevented called as Colman selection

Question 8

T helper and T killer cells

Answer 8

T helper cells: Stimulate B cells and T killer cells to divide
T killer: Cells destroy pathogen infected cells

Question 9

Monoclonal antibodies

Answer 9

Produces via hybridoma method

1) antigens injected into mouse to provoke an immune response
2) B cells are removed from mouse and fused with tumor cells that are grown in a culture . (Hybridomas)
3) antibody producing hybridomas are grown in a culture to produce many identical antibodies .

Question 10

Diagnosing diseases ( ELISA TEST)

Answer 10

1) mobile monoclonal antibodies are attached to a coloured dye and placed near the bottom of vertical strip of a plastic. Non mobile antibodies are placed near the top .
2) bottom of strip is placed near the urine sample . (Contain pathogen )
3) as urine moves up strip the antigens on the pathogen will bind to the coloured antibodies and continue to move up the strip
4) ether the pathogen reach the non mobile antibodies they will bind together .
Create coloured strip = patient has disease

Question 11

Natural active immunity and passive immunity

Answer 11

Natural active It arises from being exposed to an antigen getting the disease
Natural passive is the result of crossing of mothers antibodies through the placenta and their presence in breast milk

Question 12

Active and passive artificial

Answer 12

Active is acquired through vaccination which stimulates the immune system and lead to production of antibodies

Passive is where antibodies are injected into the body .