Immunity & Disease Flashcards
What is immunity?
It’s protection or defence against infections from:
- Bacteria
- Fungi
- Viruses
- Toxins
- Cancer
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What are the 2 main pathways of the immune system?
- Innate
- Adaptive
What is the innate immune system and give some examples…
The innate immune system is non-specific and is a protective mechanism even before infection:
- Skin, mucous membrane
- Phagocytic cells (Neutophils, macrophages, inflammation, fever)
What is the adaptive immune system and give examples.
It’s a specific response such as cell mediated immunity and humoral immunity.
The cells in this system have memory such as T-cell and B-cells
How does the skin protect our bodies from infection?
- Has an outer layer of keratin which is a mechanical barrier
- Dead skin cells constantly being sloughed off which makes it hard for invading bacteria to colonize
- Sweat and oils contain anti-microbial chemicals
How do mucous membranes help protect us from infections?
-Normal flow of mucous wash bacteria and viruses off mucous membranes For example: -Cilia in the respiratory tract. -Acid in the stomach+ vagina -Enzymes in saliva and the eyes
What are some chemical barriers in the prevention of infection in our bodies.
PROTEINS such as
- Complement, which works with other defence mechanisms of the body
- Interferons, which inhibit the replication of many viruses.
Name some Granulocytes and their role in defence…
-Neutophils, Eosinophils, Basophils
Their role is to remove dead cells and micro-organisms.
They are attracted by an inflammatory response of damaged cells.
Which cells are mainly responsible for phagocytosis?
Monocytes (macrophages)
They are in tissues and work as filters for trapping microbes.
They live longer than granulocytes and usually arrive later than granulocytes.
List some non-specific responses to infections…
Macrophages release protein signals- interluekin-1 and interleukin-6:
- Fever
- Pain, swelling redness (promote blood flow and phagocytic cells to area.
- Acute phase protein release from liver (bind to bacteria and activate complement proteins)
Which division of the immune system relies on antigens (specific substances found in foregn microbes) and Lymphocytes.
The Specific (ADAPTIVE) immune system.
Name the types of LYMPHOCYTES.
T-CELLS: produced in bone marrow and matured in thymus
B-CELLS: produced in bone marrow and matured in bone marrow and concentrated in lymph nodes and spleen.
Where are Lymphocytes produced?
They’re produced in Bone Marrow and matured in different areas:
T-CELLS: Thymus
B-CELLS: Bone marrow and concentrated in spleen and lymph nodes
Why do lymphocytes circulate around the body (in lymph and blood)
To ensure they come into contact with pathogens and eachother.
What is the role of B-Cells (lymohocytes)
They secrete antibodies (Humoral immunity and recognise pathogens outside cells)
