Immune System and Lymphatic System Lecture

Comprehensive flashcards covering the components and functions of the nonspecific and specific immune systems, lymphatic organs, and cellular responses.

White blood cells

Large, nucleated blood cells that play a major role in protecting the body from foreign substances and microorganisms.

Nonspecific Immunity

Defenses not aimed at a spécifique pathogen that are directed against all pathogens to slow the progression of disease; includes the first and second lines of defense.

Specific Immunity

The most effective immune response aimed at a specific pathogen, involving developed immunity system defenses.

Lysozyme

An enzyme found in tears, saliva, and nasal secretions that kills bacteria by breaking down their cell walls.

Mucus

A protective barrier on the inner surface of the body that blocks bacteria from sticking to inner epithelial cells.

Stomach acid (HCl)

Secreted in the stomach to kill many microorganisms found in food.

Phagocytosis

The process by which phagocytic cells surround and internalize foreign microorganisms to destroy them using digestive enzymes.

Neutrophils

Phagocytic blood cells that ingest bacteria.

Macrophages

Phagocytic blood cells that ingest bacteria and remove dead neutrophils and other debris.

Interferon

A protein secreted by virus-infected cells that stimulates neighboring cells to produce antiviral proteins to prevent viral replication.

Complement proteins

$20$ proteins found in blood plasma that help phagocytic cells bind better to pathogens and destroy the pathogen's membrane.

Inflammatory response

A nonspecific defense reaction to tissue damage that increases blood flow and vessel permeability, resulting in redness, heat, and pain.

Lymph

The fluid that leaks out of capillaries and circulates among tissue cells before being collected by lymphatic vessels.

Lymph nodes

Organs that filter lymph fluid and remove foreign materials.

Tonsils

Lymphatic tissue that forms a protective ring between the nasal and oral cavities to protect against bacteria in the nose and mouth.

Spleen

A lymphatic organ that stores blood and destroys damaged red blood cells.

Thymus gland

An organ located above the heart where T cells mature.

Lymphocytes

A type of white blood cell produced in the red bone marrow that includes B cells and T cells.

Antigen

A substance foreign to the body that causes an immune response and can bind to an antibody or T cell.

Antibodies

Proteins produced by B lymphocytes that specifically react with foreign antigens.

B cells

Lymphocytes that specifically react with foreign antigens and act as antibody factories.

Helper T cell (CD4)

A cell that identifies antigens presented by macrophages and activates both B cells and cytotoxic T cells.

Cytotoxic T cell

A lymphocyte that binds to pathogens, releases a chemical attack (cytokines), and destroys the pathogens.

Cytokines

Chemical signals that stimulate immune cells to divide and recruit them to an area of infection.

Memory cells

Long-living B or T cells exposed to an antigen during the primary response that are ready to respond rapidly if the same pathogen invades again.

Passive immunity

Temporary protection occurs when an individual receives antibodies produced by another organism.

Active immunity

Immunity that occurs after the immune system is exposed to disease antigens, resulting in immune memory.

HIV (Human Immunodeficiency Virus)

An RNA virus that specifically infects and destroys helper T cells, leading to immune system failure.

Molecular weight of an antibody

Calculated as $2(25,000) + 2(50,000) = 150,000$ based on two light chains and two heavy chains.

Pathogen

An agent that causes an infectious disease.