Chapter 13: Immunity Flashcards

A set of vocabulary flashcards covering the concepts, anatomical structures, and defenses of the immune system based on Chapter 13.

Immunity

The resistance of the body against pathogenic living things and organisms, allowing it to block pathogen entry, neutralize released toxins, and destroy abnormal or foreign cells.

Immune System

A collection of cells and proteins that work in an integrated fashion to protect the body from potentially harmful, infectious microorganisms, and plays an important role in controlling cancer, allergy, hypersensitivity, and tissue/organ transplant rejection.

Immunology

The study of the functioning and disorders of the immune system.

Innate Immune System

The functional division of the immune system that provides natural, non-specific immunity against any pathogenic organism attempting to enter the body, consisting of the first and second lines of defense.

Adaptive Immune System

The functional division of the immune system that provides specific immunity, representing the third line of defense which includes Cell Mediated Immunity and Antibody Mediated Immunity utilizing B and T cells.

First Line of Defense

A non-specific defense division manifested by physical barriers (intact skin, mucous membrane, ciliated epithelium) and biochemical barriers (saliva, mucus, HCl, gastric juice, tears, and spermine in semen).

Second Line of Defense

A non-specific innate defense mechanism consisting of phagocytes, Natural Killer Cells, inflammation, antimicrobial proteins, and fever.

Third Line of Defense

A specific adaptive immune division comprising Cell Mediated Immunity and Antibody Mediated Immunity, executed by B and T cells.

Skin

One of the largest organs of the body, measuring $1.8\,\text{m}^2$, which acts as a barrier protecting against mechanical impacts, temperature variations, microorganisms, radiation, and chemicals, while regulating body temperature, fluid balance, and serving as a reservoir for Vitamin D synthesis.

Epidermis

The outermost layer of skin composed of closely packed dead cells containing keratin and fatty acids that create a dry, salty, and acidic environment to resist bacterial degradation and microbial growth.

Langerhans Cells

Skin-resident macrophages that wander among the skin layers along with T cells to eliminate intruding microbes.

Dermis

The layer of skin directly beneath the epidermis consisting of living cells, blood vessels, nerves, sweat glands, and sebaceous glands.

Sebum

An oil-like substance secreted by sebaceous glands into hair follicles that contains acids forming a thin chemical barrier on the skin surface.

Hypodermis

The layer located below the dermis containing mainly fat-storing adipose tissue and connective tissue, which serves as an insulating layer connecting the skin with underlying muscles and bones.

Mucosa

The internal epithelial lining of organs such as the digestive tract, respiratory passage, lungs, and urinary tract containing mucous-secreting cells that function as both a physical barrier and a biochemical barrier containing antimicrobial peptides.