bio: ch. 21/42 - blood typing, immunology & viruses

ABO blood group

Features 2 antigens - A antigen & B antigen.

Type A

Only the A antigen is present.

Type B

Only the B antigen is present.

Type AB

Both A & B antigens are present.

Type O

Neither A nor B antigens are present.

Rh antigen

Also known as the D-antigen; indicates Rh positive or negative.

Rh positive

Presence of the Rh antigen.

Rh negative

Absence of the Rh antigen.

Antigens

Proteins on the cell that can cause an immune response.

Antibodies

Plasma proteins that bind to foreign antigens, produced by B-lymphocytes.

Agglutination

Process where antibodies cause bound antigens to clump together.

Hemolysis

Destruction of red blood cells due to agglutination.

Erythrocytes

Another term for red blood cells.

Leukocytes

White blood cells involved in immune responses.

Monocytes

Type of agranulocytes that can differentiate into macrophages.

Lymphocytes

Second most abundant type of leukocyte; includes T-cells and B-cells.

Neutrophils

Most common type of leukocyte, active phagocytes.

Eosinophils

Leukocytes involved in responses to parasitic infections and allergies.

Basophils

The rarest leukocyte that releases chemicals mediating inflammation.

T-cells

Lymphocytes that mature in the thymus and do not produce antibodies.

B-cells

Lymphocytes that mature in bone marrow and produce antibodies.

Spleen

Organ that filters blood and houses leukocytes.

Thymus

Organ where T-lymphocytes mature.

Lymphatic system

System that collects excess fluid, transports fats, and plays a role in immune functions.

Lymph nodes

Small structures that filter lymph and trap pathogens.

Cytosol

Fluid component of the cytoplasm where metabolic reactions occur.

Reticular connective tissue

Primary tissue in the lymphatic system that traps pathogens.

Macrophages

Large phagocytes that consume dead cells and pathogens.

Chemotaxis

Movement of leukocytes towards the site of injury or infection.

MALT

Mucosa-associated lymphoid tissue involved in immune responses.

Peyer’s patches

Specialized lymphoid follicles in the ileum of the small intestine.

Tonsils

Lymphoid tissues located around the oral and nasal cavities.

Appendix

Lymphoid tissue in the large intestine that helps defend against bacteria.

Innate immunity

Immediate and non-specific immune response.

Adaptive immunity

Slower immune response that is specific to particular antigens.

Specific immunity

Targets unique antigens from specific pathogens.

Nonspecific immunity

Responds to any pathogen or class of pathogens.

Complement system

Group of proteins involved in innate immunity that enhance immune responses.

Classical pathway

Activation pathway of the complement system via antibodies.

Alternative pathway

Activation pathway that begins when complement proteins bind to pathogens.

Opsonization

Binding of complement proteins to pathogens enhancing phagocytosis.

Cytokines

Proteins secreted by immune cells that regulate immune responses.

Tumor necrosis factor (TNF)

Cytokine that induces inflammation and attracts phagocytes.

Interferons (INF)

Cytokines produced in response to viral infections, inhibiting viral replication.

Interleukins

A class of cytokines that stimulate immune responses.

Inflammatory response

Reaction to cellular injury, involving vasodilation and immune cell recruitment.

Helper T-cells

CD4 T-cells that assist in the immune response.

Cytotoxic T-cells

CD8 T-cells that kill infected or abnormal cells.

Immunogen

Type of antigen that generates an immune response.

Self-antigens

Normal proteins on the body’s cells that are not immunogenic.

Hapten

A non-immunogenic substance that becomes immunogenic when attached to a protein.

Exogenous antigen

Antigen that originates outside the cell.

Endogenous antigen

Antigen that originates inside the cell.

Clone

Population of T-cells specific to an antigen.

Major histocompatibility complex (MHC)

Molecules presenting antigens on cell surfaces.

Lytic cycle

Phage replicative cycle culminating in host cell death.

Lysogenic cycle

Phage remains within the host cell without destroying it.

Provirus

Viral DNA integrated into the host cell's DNA.

Retrovirus

Virus that uses reverse transcriptase to convert RNA to DNA.

Vaccine

Substance that triggers immune protection using weakened or killed pathogens.

Prions

Infectious proteins that cause disease without nucleic acids.