Immune system Flashcards
how do cells communicate?
Direct interaction, diffusible chemical communication, electrical signals
Threats handled by our immune system
Pathogens, abnormal cells such as tumour, our own dead or damaged cells, certain nonpathogenic foreign substances, out own healthy cells (Inappropriately)
Types of defence
Innate and adaptive they both communicate with one another
Innate defenses
Barriers- skin mucus membrane
phagocytes, macrophages, Natural killer cells (attack cancer)
inflammatory-response to tissue damage
Fever
Adaptive defence
Specificity
diversity
Self/nonself recognition
memory
Antibodies and T-cell receptors
an antibody is a individual molecule a set of antibodies (Ab) is called an immunoglobulin (lg) class
two regions constant region (C)- same in each lg class
Variable region (V) - Different in each antibody
What is an Epitope?
Part of the antigenic molecule that binds the antibody
How are different antibodies generated?
By editing fenes during development of B cells that produce antibodies. The lg genes are randomly and independently mutated in each develpoing B cell
What are T-cell receptors?
Glycoproteins located on the surface of T cells
- manifest specificity and diversity
- bind to antigens
- their diversity is also generated by gene rearrangments
What are Lymphocytes and what do they do?
They are adaptive defense cells derived from stem cells in the bone marrow
What are B lymphocytes
B-cells mature in bone marrow
What are T lymphocytes
T-cells mature in the thymus
What is the B cells Structure?
Have antibodies on surface that serve as antigen receptors. Binding tells the cell that there is a foreign molecule
B cell activation
Activated by antiden binding of by inter activation with a helper T cell
What do antibodies do?
Serve as membrane bound receptors in B cells
-coast virus and bacteria, preventing their attachment to epithelia
Coat cells, viruses and particals for macrophage recognition and destruction
