Chapter 16: Lymphatic System

Lymphatic system

A network of vessels, nodes, and organs that returns fluid to the bloodstream and helps defend against infection.

Lymph

A clear fluid that circulates through the lymphatic system, containing white blood cells and waste products.

Lymph vessels

Thin-walled vessels that transport lymph throughout the body.

Lymph nodes

Small, bean-shaped structures that filter lymph and house lymphocytes to fight infection.

Lymphocytes

A type of white blood cell involved in the immune response.

T cells

Lymphocytes that mature in the thymus and destroy infected or cancerous cells.

B cells

Lymphocytes that produce antibodies to fight infections.

Thymus gland

An organ in the chest where T cells mature; most active during childhood.

Spleen

The largest lymphatic organ; filters blood, removes old red blood cells, and stores lymphocytes.

Tonsils

Lymphatic tissue in the throat that helps trap and destroy pathogens.

Adenoids

Lymphatic tissue located behind the nose that helps fight infections.

Peyer’s patches

Lymphoid tissue found in the walls of the small intestine that monitors intestinal bacteria.

Thoracic duct

The main lymphatic duct that drains lymph from most of the body into the left subclavian vein.

Right lymphatic duct

Drains lymph from the upper right side of the body into the right subclavian vein.

Interstitial fluid

Fluid between cells that becomes lymph when it enters lymphatic vessels.

Lacteals

Specialized lymph capillaries in the intestines that absorb fats.

Chyle

Milky fluid consisting of lymph and absorbed fats from the digestive system.

Immune system

A system of cells and organs that protects the body from infection and disease.

Innate immunity

Nonspecific defense mechanisms present at birth, such as skin and inflammation.

Adaptive immunity

Specific immune responses developed after exposure to pathogens.

Antigen

A substance that stimulates an immune response, often found on the surface of pathogens.

Antibody

A protein produced by B cells that binds to a specific antigen to neutralize it.

Immunity

The body's ability to resist disease through immune responses.

Active immunity

Immunity developed after exposure to an antigen through infection or vaccination.

Passive immunity

Temporary immunity obtained by receiving antibodies from another person or source.

Autoimmune disorder

A condition in which the immune system mistakenly attacks the body’s own tissues.

Allergy

An exaggerated immune response to a harmless substance (allergen).

Anaphylaxis

A severe, life-threatening allergic reaction that can cause shock and difficulty breathing.

Lymphedema

Swelling caused by accumulation of lymph due to blocked or damaged lymphatic vessels.

Lymphadenitis

Inflammation of the lymph nodes, often due to infection.

Hodgkin’s lymphoma

A cancer of the lymphatic system characterized by the presence of Reed-Sternberg cells.

Non-Hodgkin’s lymphoma

A group of blood cancers affecting the lymphatic system, not involving Reed-Sternberg cells.

Immunization

The process of developing resistance to disease through vaccination.

congenital myasthenia gravis

born with abnormally large thymus gland that produces too many antibodies that attack neuromuscular junction

immunoglobulins

proteins that function as antibodies coming in GAMED classes