The Lymphatic System and Immunity - Vocabulary Flashcards

A set of vocabulary flashcards covering key concepts in immunity and the lymphatic system from the lecture notes.

Immunity

The ability to fight off pathogens and prevent disease; main types are innate and adaptive.

Innate immunity

Present at birth; rapid, nonspecific defense with physical barriers, internal defenses, and antimicrobial substances.

Adaptive immunity

Develops after exposure to specific pathogens; slower but targeted; involves memory.

Physical barriers

First line of defense (e.g., skin) that blocks pathogen entry.

Mucous membranes

Membranes lining body cavities that trap microbes.

Cilia and mucus

Mechanical barrier that traps and expels microbes from airways and digestive tracts.

Internal defenses

Non-skin defenses such as phagocytes, natural killer cells, fever, and antimicrobial substances.

Phagocytes

Cells that engulf and destroy pathogens (e.g., neutrophils, macrophages).

Macrophages

A type of phagocyte that ingests pathogens and presents antigens.

Natural killer cells

Lymphocytes that destroy infected or cancerous cells without prior exposure.

Fever

Elevated body temperature that inhibits microbes and enhances immune responses.

Interferons

Proteins that inhibit viral replication and activate neighboring cells in innate defense.

Complement system

Group of plasma proteins that enhance immune responses and can lyse pathogens.

Iron-binding proteins

Proteins that limit iron availability to microbes, inhibiting growth.

Antimicrobial peptides

Short peptides that directly kill microbes.

Inflammation

Localized nonspecific response to tissue damage; recruits immune cells; increases blood flow and permeability.

Antigens

Foreign substances that trigger an immune response.

Cell-mediated immunity

Adaptive immunity where T cells directly attack infected cells.

Antibody-mediated immunity

Adaptive immunity where B cells produce antibodies to neutralize pathogens.

Lymphatic system

Network of lymphatic vessels and organs; maintains fluid balance and participates in immunity.

Lymph

Clear fluid similar to blood plasma that circulates in lymphatic vessels.

Lymphatic vessels

Thin-walled vessels that transport lymph throughout the body.

Lymph nodes

Filters lymph and houses B cells and T cells; makes immune responses.

Thymus

Primary lymphatic organ where T cells mature.

Spleen

Largest lymphatic organ; white pulp for immune responses, red pulp for filtering blood and storing platelets.

Lymphatic nodules

Egg-shaped, capsule-free masses of lymphatic tissue in mucous membranes.

Lymphatic capillaries

Small, blind-ended vessels that absorb interstitial fluid to form lymph.

Thoracic duct

Lymphatic duct draining the left side of the body and lower limbs; empties into left internal jugular and left subclavian veins.

Right lymphatic duct

Drains lymph from the right side of the head/neck, right upper limb, and right thorax; empties into the junction of the right internal jugular and right subclavian veins.

Primary lymphatic organs

Organs where lymphocytes mature (red bone marrow and thymus).

Red bone marrow

Produces mature B cells and immature T cells; located in flat bones and ends of long bones.

Secondary lymphatic organs

Sites where immune responses are activated (lymph nodes, spleen, lymphatic nodules).

White pulp

Lymphatic tissue in the spleen involved in immune responses.

Red pulp

Spleen region that filters blood, removes old red blood cells, and stores platelets.

Lymphocyte proliferation

Clonal expansion of lymphocytes to fight a specific antigen.

Clonal selection

Process by which specific lymphocytes are selected and multiplied for a given antigen.

Helper T cells

Activate B cells and cytotoxic T cells; coordinate immune responses.

Cytotoxic T cells

Destroy infected or abnormal cells directly.

B cells

Differentiate into plasma cells and produce antibodies.

Plasma cells

Antibody-secreting cells derived from B cells.

Antibodies

Immunoglobulins that bind to antigens and neutralize or mark pathogens.

Immunoglobulins

Classes of antibodies (IgG, IgA, IgM, IgD, IgE).

IgG

Most abundant antibody; provides long-term immunity.

IgA

Antibody found in mucous membranes; protects mucosal surfaces.

IgM

First antibodies produced during an immune response.

IgD

Involved in B cell activation.

IgE

Associated with allergic reactions and defense against parasites.

Vaccination

Introduction of harmless antigen to stimulate memory cell formation and long-term immunity.

Immune memory

Ability to respond more rapidly and effectively on re-exposure to a previously encountered antigen.

Memory cells

Long-lived lymphocytes that persist and respond quickly upon re-exposure.

Aging & Immunity

Aging reduces immune function; T and B cells become less responsive, increasing infection risk.

Autoantibodies

Antibodies that target the body's own tissues.

Influenza vaccine

A vaccine example recommended for elderly to boost immunity.

Vaccination & Aging

Elderly should receive regular vaccines; protection remains, though response may be reduced.

Lymph nodes afferent/efferent

Afferent vessels bring lymph into a node; efferent vessels carry lymph away.

Lymphatic nodules location

Located in mucous membranes of GI, urinary, reproductive, and respiratory tracts.

Lymphatic nodules lack capsule

Not surrounded by a connective tissue capsule.

Lymph flow pumps

Skeletal muscle pump and respiratory pump assist lymph movement.

Lymph flow

Movement of lymph toward the venous system within the body.

Primary vs Secondary lymphatic organs

Primary: maturation sites (red bone marrow, thymus); Secondary: sites of immune activation (lymph nodes, spleen, nodules).