Host Defense I: Innate Immunity Flashcards

A set of 30 vocabulary flashcards covering the physical, chemical, and cellular components of the innate immune system based on the lecture notes.

First Line Defense

A non-specific defense that includes any barrier blocking invasion at a portal of entry.

Second Line Defense

A non-specific internalized system of protective cells and fluids, including inflammation, fever, and phagocytosis.

Third Line Defense

A specific defense acquired on an individual basis as white blood cells encounter foreign substances, resulting in a memory response.

Keratin

A protein in the epidermis that, along with continuous layering and closely packed cells, provides a physical barrier against microorganisms.

Ciliated cells

Cells in the respiratory tract that move microorganisms to the pharynx to be cleared, preventing them from entering the lower respiratory system.

Microbial Antagonism

The antagonistic effect good microbes have against intruder microorganisms by competing for nutrients, attachment points, or altering the environment.

Lysozyme

An enzyme found in tears and saliva that breaks down peptidoglycan in the cell walls of bacteria.

Gastric juices

Stomach fluids with an acidic pH that kill most bacteria.

Phagocytosis

The process by which phagocytes ingest or engulf other cells or particles.

Neutrophils

General purpose phagocytes that react early in inflammation and are the primary component of pus.

Monocytes

Phagocytes that travel in the blood before emigrating into tissues.

Macrophages

The cell type into which monocytes transform after they emigrate out of the bloodstream and into the tissues.

PAMPs (Pathogen Associated Molecular Patterns)

Molecules present only on microorganisms that act as red flags for the immune system.

PRRs (Pattern Recognition Receptors)

Receptors used by host phagocytes to recognize Pathogen Associated Molecular Patterns.

Chemotaxis

The first stage of phagocytosis where phagocytes migrate to the region of inflammation.

Adhesion

The stage of phagocytosis where phagocytes identify and stick to foreign cells using pattern recognition.

Phagosome

A vacuole formed when a phagocyte engulfs and internalizes a microorganism.

Phagolysosome

A structure formed when a lysosome migrates and fuses with a phagosome to destroy ingested material.

Exocytosis

The process by which small bits of indigestible debris are released from the phagocyte during the elimination stage.

Histamine

A chemical substance released from basophils and mast cells when cells are damaged, causing blood vessel dilation.

Vasodilation

The dilation of blood vessel walls which increases blood flow to a damaged area, causing redness and warmth.

Leukocytosis

An increase in the number of white blood cells in the blood.

Diapedesis

The process where neutrophils exit the blood and enter the tissue to aid an infection.

Granuloma

A pocket of tissue that surrounds and walls off an inflammatory agent during chronic inflammation.

Pyrogens

Substances that stimulate the hypothalamus to raise the body temperature.

Hypothalamus

The part of the brain that controls the body's temperature.

Complement

A group of $26$ different interacting proteins found in blood plasma that can form a Membrane Attack Complex.

Membrane Attack Complex (MAC)

A complex formed by complement proteins that serves to lyse foreign cells.

Opsonization

A process where the attachment of the Membrane Attack Complex allows phagocytic cells to recognize and attach to foreign cells faster.

Interferons (IFN)

Proteins synthesized by a virus-infected cell that induce nearby uninfected cells to produce proteins that eliminate foreign genes.