Immunology I - Innate Immunity

Flashcards covering key concepts in Innate Immunity, including lines of defense, cells, and processes.

What is susceptibility in the context of immunity?

Lack of resistance to a disease.

What is immunity?

The ability to ward off disease.

What is susceptibility in the context of immunity?

Lack of resistance to a disease.

What is immunity?

The ability to ward off disease.

What is the difference between innate and adaptive immunity?

Innate immunity is defenses against any pathogen, while adaptive immunity is resistance to a specific pathogen.

What are the three lines of defense?

1) Intact skin, mucous membranes; 2) Phagocytes/ inflammation/fever/antimicrobial substances; 3) Specialized lymphocytes, antibodies.

What is the role of Toll-like receptors (TLRs)?

TLRs attach to pathogen-associated molecular patterns (PAMPs) and induce cytokines.

What is the role of cytokines?

Regulate the intensity and duration of immune responses.

What is the function of keratin in the epidermis?

Protective protein.

What is the function of mucus membranes?

Traps microbes.

What is the function of the ciliary escalator?

Transports microbes trapped in mucus away from the lungs.

How does the lacrimal apparatus contribute to defense?

Washes the eye.

How do saliva and urine contribute to defense?

Saliva washes microbes off, urine flows out.

What are some chemical factors involved in innate immunity?

Fungistatic fatty acid in sebum, low pH of skin, lysozyme, low pH of gastric juice and vaginal secretions.

What is microbial antagonism/competitive exclusion?

Normal microbiota compete with pathogens or alter the environment.

What are commensal microbiota?

One organism benefits, the other is unharmed; may be opportunistic pathogens.

What are granulocytes?

Leukocytes with granules in their cytoplasm that are visible with a light microscope.

What is the function of neutrophils?

Phagocytic; work in early stages of infection.

What is the function of basophils?

Release histamine; work in allergic responses.

What is the function of eosinophils?

Phagocytic; toxic against parasites and helminths.

What are agranulocytes?

Leukocytes with granules in their cytoplasm that are not visible with a light microscope.

What is the function of monocytes?

Mature into macrophages in tissues where they are phagocytic.

What is the function of dendritic cells?

Phagocytic cells found in the skin, mucous membranes, and thymus.

What is the function of lymphocytes.

T cells, B cells, and NK cells; play a role in adaptive immunity

What is phagocytosis?

Ingestion of microbes or particles by a cell, performed by phagocytes.

What are the phases of phagocytosis?

Chemotaxis and adherence, ingestion, formation of phagosome, fusion with lysosome, digestion, formation of residual body, discharge.

What is the role of M protein in microbial evasion of phagocytosis?

Inhibit adherence.

What is the role of leukocidins in microbial evasion of phagocytosis?

Kill phagocytes.

What is the role of membrane attack complex in microbial evasion of phagocytosis?

Lyse phagocytes.

What are some vasoactive mediators activated during inflammation?

Histamine, Kinins, Prostaglandins, Leukotrienes, Cytokines

List the events of inflammation

1) Tissue damage; 2) Vasodilation and increased permeability of blood vessels; 3) Phagocyte migration and phagocytosis; 4) Tissue repair

What are the advantages of fever?

Increases transferrins, increases IL-1 activity, produces interferon.

What are the disadvantages of fever?

Tachycardia, acidosis, dehydration, can be fatal.

How do cytokines cause fever?

Cytokines cause the hypothalamus to release prostaglandins that reset the hypothalamus to a higher temperature.

What is the complement system?

Serum proteins activated in a cascade.

What are the outcomes of complement activation?

Opsonization, cytolysis, and inflammation.

How do capsules help bacteria evade complement?

Prevent C activation.

What is the role of IFN-a and IFN-b?

Cause cells to produce antiviral proteins that inhibit viral replication.

What is the role of IFN-g?

Causes neutrophils and macrophages to phagocytize bacteria.