The Innate Immune System

This set of flashcards covers the mechanisms of the innate immune system, including physical barriers, chemical weaponry, phagocytic cells, and the inflammatory response.

What is the first line of defense in the immune system, primarily composed of physical and chemical barriers?

The innate, or nonspecific, defense system

What is the specific description of the skin's membrane that provides a physical barrier against microorganisms?

A tough, keratinized epithelial membrane

Which four body tracts are lined with mucous membranes to provide physical protection against the outside world?

Respiratory, digestive, urinary, and reproductive tracts

What are defensins?

Peptides in the skin and membranes that help keep bacteria and fungi from setting up shop around inflamed or scraped skin

What is the most abundant type of white blood cell, which self-destructs after devouring a pathogen?

Neutrophils

What substance is formed by the accumulation of dead neutrophils?

Pus

From which type of white blood cells are macrophages derived?

Monocyte white-blood cells

What protein found on the surface of normal, healthy cells allows Natural Killer (NK) cells to identify them?

$MHC1$, or major Histocompatibility Complex

What process of programmed cell death do Natural Killer (NK) cells trigger when they detect a defective cell?

Apoptosis

Which specialized cells in connective tissue release histamine molecules to trigger an inflammatory response?

Mast cells

What process, caused by histamine, creates redness and heat at the site of an injury?

Vasodilation

What term describes the release of neutrophils from the bone marrow into the bloodstream during an infection?

Leukocytosis

Which chemicals are released by white blood cells and macrophages to reset the body's thermostat and induce fever?

Pyrogen chemicals

Which part of the brain is targeted by pyrogens to raise the body's temperature?

The hypothalamus

During a fever, why does the body instruct the liver and spleen to sequester iron and zinc?

To prevent those minerals from contributing to bacterial growth