Immuntiy Flashcards
Inflammatory response causes the release of:
Histamine Kinins Prostaglandins PDGF Complement
Inflammatory response
A non-specific attack following an injury or introduction of pathogens
Histamine
Promotes vasodilation of local arterioles, increases permeability of local capillaries, and slows movement of bacteria and virus
Kinins
Introduce chemotaxis of leukocytes and cause pain
Prostaglandins
Sensitize blood vessels for the inflammatory response, cause pain
PDGF
Platelet Derived Growth Factor – stimulate fibroblast activity and repair of damaged tissue
Complement
Destroys bacteria.
A group of ~20 proteins. They are activated by a cascade reaction – one activates the next. They form a hollow pore, causing the cytoplasm to leak out of invading organisms
General effects –
Vasodilation and increased permeability.
Neutrophils, monocytes, & lymphocytes attracted to area, leak out of capillary & move to injury via chemotaxis.
Increased heat increases metabolic rate of cells.
Pain, swelling.
Blood clots wall off area to prevent injury to surrounding area.
Phagocytes remove cellular debris, bacteria, & pus.
Tissue heals.
Interferons
Chemicals produced by infected cells, which confer some protection to non-infected cells. “Warned” cells will produce proteins which inhibit viral replication.
MHC
Major Histo-compatibility Complex – a protein marker added to your cells at 3 months of age. This protein tells your immune system which cells belong to you. Cells without MHC are of right and destroyed.
Acquired immunity
Occurs when the immune system reacts with an antigen. Antibody is produced, memory cells circulate in the blood, and are activated upon re-infection, preventing you from getting sick again. I.e. Getting the mumps or measles.
Passive immunity
Antibody passed from mom to fetus via the placenta or breastmilk, especially the colostrums, or first milk produced. Gives the infant temporary immunity lasting from a few weeks to months.
Active immunity
Naturally acquired from a disease or artificially from a vaccination.
Humoral immunity
Antibody from lymphocytes that circulate as soluble proteins in plasma and lymph. Body fluids were called humors.
They provide immunity from toxins, bacteria, and virus in body fluids.
Cell-mediated Immunity
Depends on the actions of lymphocytes, not just the antibody.
They provide immunity from bacteria and virus host cells, fungus, cancer cells, protozoans, and worms.
Lymphocytes
B cells & T cells - both have antigen receptors on their surface.
All blood cells come from stem cells in bonemarrow or the liver in a fetus.
Initially, all are alike. Lymphocytes migrate to either the thymus & become T cells, or the bone and become B cells.
There’s a high concentration of B & T cells in lymph nodes & the spleen.
B Cells
From bone. Provide humoral immune response. Originally identified in the Bursa of Fabrinicus in birds. B cells have bound antibody on their surface.
T Cells
From the thymus. Provide cell mediated immune response. T cells have antigen receptors.
Antigen triggers:
Lymphocytes divide and produce effector cells.
B lymphocytes produce plasma cells, which produce antibody.
T-cells produce:
- Cytotoxic T cells
- Helper T cells
- Cytokine
I.e. Macrophage + antigen + helper T cells
- Cytotoxic T cells
Destroy infected cells and cancer cells, and release perforin which is a protein pore, and lyses open infected or cancer cells.
- Helper T cells
Stimulate humoral and cell mediated immunity
- Cytokine
A chemical produced in one cell that regulates the activity of neighbor cells
I.e. Macrophage + antigen + helper T cells
T cells produces the cytokine interleukin 1
This signals the release of interleukin 2
Interleukin 2 stimulates helper T cell growth
This triggers the increase of helper T cells and interleukin 2
Activates B cells for humoral response
Triggers the differentiation of T lymphocytes into cytotoxic T
cells which destroy the infected cells.
