Chapter 21

Drain excess tissue fluid

Returns it to the bloodstream through the lymphatic system.

Absorbs fats

The lymphatic system absorbs fats from the digestive tract.

Protects body from disease

The lymphatic system plays a role in the immune response.

Interstitial Fluid

Fluid found between cells that comes from blood plasma.

Lymph

Interstitial fluid once it enters lymphatic vessels.

Skeletal muscle contractions

One of the mechanisms that help lymph move since lymph does not have a pump.

Breathing movements

Another mechanism that assists in the movement of lymph.

One-way valves

Valves in the lymphatic system that prevent backflow of lymph.

Lymphatic Capillaries

Tiny vessels that collect interstitial fluid.

Lacteals

Specialized lymph capillaries in the small intestine that absorb fats.

Cisterna Chyli

Enlarged sac that collects lymph from the legs, pelvis, and digestive organs.

Right Lymphatic Duct

Drains the right side of the head, right arm, and right chest, emptying into the right subclavian vein.

Thoracic Duct

Drains all the rest of the body, emptying into the left subclavian vein.

Antigen

A foreign substance/pathogen marker that causes an immune response.

Antibody

A protein made by B cells that attacks a specific antigen.

B Cells

Cells that produce antibodies when activated.

T Cells

Cells that attack infected cells and help regulate the immune response.

Natural Killer (NK) Cells

Cells that kill virus-infected cells and cancer cells.

Innate Immunity

Fast and nonspecific immunity that you're born with.

Adaptive Immunity

Specific immunity that builds memory and is slower at first.

Humoral Immunity

Immunity involving B cells and antibodies.

Cellular Immunity

Immunity involving T cells that kill infected cells.

Thymus

Organ where T cells mature.

Bone Marrow

Produces blood cells and is where B cells mature.

Lymph Nodes

Filter lymph and remove pathogens, debris, and foreign material.

Spleen

Filters blood and removes old red blood cells and bacteria.

Tonsils

Protect against inhaled or swallowed pathogens.

Peyer’s Patches

Located in the small intestine, they protect against swallowed pathogens.

IgM

First antibody made during an infection.

IgG

Most common antibody and the main antibody in a second infection.

IgA

Found in saliva, tears, mucus, and breast milk; protects body surfaces.

IgE

Antibody associated with allergies and anaphylaxis.

IgD

Found on B cell surfaces; acts as a B cell receptor.

Active Immunity

Immunity where you make your own antibodies.

Passive Immunity

Immunity where you receive antibodies from another source.

Type IV Hypersensitivity

Delayed allergic reaction, examples include poison ivy and TB skin test.