Bio112 Topic 16: The Immune System Flashcards

Flashcards covering key vocabulary related to the immune system, based on lecture notes from Bio112 Topic 16.

Pathogen

An organism or molecular system capable of causing infection and cellular dysfunction

Leukocytes

White blood cells that originate in the bone marrow and circulate through the blood and lymph vessels.

Innate (nonspecific) Immunity

A rapid immune response that functions the same way regardless of the invader, acting as the first line of defense through cell-mediated and abiotic factors (barriers & chemical defenses).

Adaptive (acquired) Immunity

An immune response that develops after exposure to a pathogen, targeting specific molecules that are either freely circulating in blood or extracellular fluid, involving cell-mediated and humoral (antibodies) responses.

MAMPS or PAMPS

Molecules commonly found in or on pathogens but not self, which are recognized by Toll-like receptors (TLRs) to trigger an augmented innate immune response through signaling.

Cytokines

Innate immune system signaling molecules that attract other immune cells, stimulate immune cells, inhibit viral replication, and can induce fever and inflammation.

Interferons (IFNs)

A family of proteins secreted by virus-infected cells, stimulating nearby cells to produce PKR, mobilizing natural killer cells, and promoting the development of macrophages from monocytes.

Pyrogens

Cytokines that cause fever by targeting the hypothalamus to re-set the body’s thermostat to a higher level.

Antigen

A foreign molecule that triggers a humoral immune response or is recognized by an antibody.

Epitope

The specific small portion (domain) of an antigen involved in the physical interaction with a lymphocyte or antibody.

T cells

Lymphocytes that mature in the thymus gland and include cytotoxic T cells (TC) and helper T cells (TH).

B cells

Lymphocytes that mature in the bone marrow and differentiate into plasma cells that synthesize and secrete antibodies.

Primary immune response

Occurs after initial exposure to an antigen; the response is slower and smaller.

Secondary Immune response

Occurs upon second exposure to the same antigen; resulting in a faster and larger response due to memory cells.