Unit 4 - Specific Defenses Flashcards
How is the Specific Immune Response brought about?
When an antigen presenting cell (A phagocyte) finds the Th lymphocyte with antigen receptors that match the antigen it gathered from the pathogen, this causes the Th lymphocyte to become active. However, a circulating Th cell can find its matching antigen on its own, or with the help of a B cell.
Where are Lymphocytes made?
In the bone marrow
Where do the different types of lymphocytes (B and T lymphocytes) mature?
B lymphocytes mature in the bone marrow, while T lymphocytes mature in the Thymus Gland.
What do mature inactivated T and B lymphocytes do?
They travel around the body looking for foreign antigens on cells. When not doing this they will usually gather in the Lymph nodes.
What happens when a lymphocyte is activated?
It begins to clone itself thousands of times. This clone army splits into two: the active half which fights off the current infection and the memory cells which are stored for the next time this exact pathogen infects the body.
When activated, what do B lymphocytes produce?
Antibodies.
What do Helper T lymphocytes (Th cells) do in the specific immune response?
They clone themselves thousands of times, and the active half of the clones begin to produce specific cytokines which attract the matching Cytotoxic T cells and B cells for that antigen.
What are antibodies and what do they do?
They a proteins in the shape of a ‘Y’ with two antigen receptors at the heads. They use their antigen receptors to attach themselves to the pathogens with the matching antigen, thus binding the pathogen in place. This makes the pathogens more susceptible to Phagocytosis.
How do Cytotoxic T lymphocytes help in the specific immune response?
The Tc Cells release enzymes which create pores in the target cell. These enzymes then enter the cell and activate the self destruct pathways, which cause the cell to self destruct. This is called Apoptosis.
What do memory cells do?
They wait until the current pathogen’s second infection (or any after that), and then they cause the specific immune response to react more quickly and become more efficient, causing the pathogen to have less of a chance.
What are names of the two response that T and B lymphocytes in involved in?
T-Lymphocytes are involved in a cell-mediated response, and B-Lymphocytes are involved in the Humeral response.
What is an over-reaction to a usually harmless non-self antigen called?
An allergy.
What is an immune reaction to self antigens called?
Autoimmune disease.
