Question

Immunology Activity

Using the following components of the immune system, decide which component will act first, second, third, etc. . . to combat the following pathogens.

Skin

Mucous membranes

Mucus

Sebum

Gastric juices

T helper cells

Cytotoxic T cells

B cells

Antibodies

Cytokines

Interferons

NK cells

Macrophages and dendritic cells

Basophils

Neutrophils

Eosinophils

Complement

Lacrimal apparatus

Scenarios:

Staph aureus infection of the follicle on skin. S. aureus can produce toxins and tissue destruction as it invades the tissues.

E. coli found inside a poorly cooked hamburger patty. Remember, E. coli has the capability to produce toxins and is Gram-negative therefore has endotoxin present as well.

Mycobacterium tuberculosis breathed in after being exposed to a patient with active disease. M. tuberculosis can live inside phagocytic cells as its cell wall is resistant to digestion.

Influenza virus infection from sharing a glass of water with a sick friend. This virus causes inflammation of the upper respiratory tract leading to further complications.

Herpes Simplex Type 2, causes ulcerous lesions, contracted through skin to skin contact with a person with an active lesion. This virus goes into latency in the patient.

Cat dander exposure to someone who is intensely allergic to cats.

Immune System Component:	Action of the component:

Answer 1

Immune system of the component	Action of the component
Skin	acts as a water proof mechanical barrier
Mucous membranes	traps microbe
Mucus	flushing action, contains enzyme that breaks down the cell wall of many bacteria.
Lacrimal apparatus	secretes tears which causes flushing action and contains enzyme tha breaks down cell wall of many bacteria.
Gastric juices	kills swallowed bacteria and parasites
Sebum	contains fatty acid which is fungistatic
Neutrophils	find, kill and ingest pathogens
T helper cells	Each T helper cell specific for specific pathogen
Cytotoxic T cells	they form holes in walls of pathogens and kill them.
Macrophages and dendritic cells	ingest dead cells and waste products. Show the proof of invasion to T-cells in the lymph nodes.

B cells	they produce antibodies that immobilized them until consumed by macrophage. A few B cells also act as memory cells.
Complement	they bind to pathogens and destroy them
Cytokines	act as chemical messengers in immune response
Interferons	give protection against viruses and tumor cells
Antibodies	bind to pathogens and damage them
Basophil	involved in allergic reactions
Neutrophil	phagocytes
NK cell	recognise and respond to viruses, parasites and bacteria

The first line of defence includes skin, mucous membranes, mucus, Lacrimal apparatus, gastric juices, sebum, NK cells.

The second line of defence includes neutrophils, T helper cells, cytotoxic T cells, macrophages and dendritic cells, B cells.

The third line of defence includes rest.