Immune system

Non-specific physical barriers

Fluora found on skin, along lining of digestive tract, vagina.

Fluora compete for sites

Suitable in certain conditions (temps, saltiness)

Non-specific chemical barriers

Anti microbial sebum, prevents pathogens from passing through

Acidic pH low enough to break down pathogens

Lysosomes in tears break down pathogens

Non-specific immune system

White blood cells (phagocytes) that carry out phagocytosis ingesting any invading microbes.

Secondary defence system

Phagocytes (non-specific) —> ingest pathogens

Lymphocytes (specific to antigens) —> B lymphocytes produce antibodies/ t lymphocytes assist in b lymphocytes in doing their role.

Neutrophils

Made in bone marrow, multi-lobe nucleus

Patrol on tissue fluid

Short lived

Collect in an area and form pus.

Macrophages

Made/ produced in bone marrow, larger cells

Monocytes in blood when there is no infection

When there is an infection, monocytes become macrophages

Macrophages breaks and ingests pathogens, where the antigens are released from microbes, macrophages uses the antigens on surface of cell, aids rest of immune system cells.

Antigen presenting cell (APC)

Processes an antigen and presents fragments of it on it’s cell surface bound to MHC molecules, in order to activate T lymphocytes and initiate an immune response.

Clonal selection

Process by which a lymphocyte with a complementary receptor to an antigen is selected, activated, and divides by mitosis to form a clone of identical cells.

Cytokines

Cell signaling molecules, released by cells of the immune system

Opsonins

Proteins responsible for assisting process of phagocytosis.