Lymphatic & Immune Systems

This is Unit Eight of Medical Terminology: the lymphatic and immune systems. At twenty entries it is the shortest unit in the course. It is also the first unit that leans on another system unit. Units One through Four supply the machine — word parts, joining rules, suffixes, prefixes, orientation. Unit Seven supplies the blood and the vessels this system runs alongside, and five of its numbers are cited here. The system has two halves and the vocabulary splits the same way. One half is drainage: a fluid, the vessels that carry it, the nodes that filter it, and three organs. The other half is the response itself — immunity, and the terms for how it works and how it misfires. Almost every disease term here is a Unit Two suffix on a root introduced in the first ten entries. Itis, oma, pathy, megaly, ectomy, logy. Two suffixes are new, and each is defined against something already taught: globulin against globin from the blood unit, phylaxis against the prefix that reverses it. Four terms arrive as two pairs that cannot be learned separately. Antigen with antibody, active immunity with passive. Each definition contains the other, and the book numbers each pair adjacently for that reason. By the end you will be able to do five things. One: name the combining forms for lymph, the node, and the vessel. Two: name the three lymphatic organs and the two immune forms. Three: state what phylaxis and globulin contribute, and how one gets reversed. Four: trace lymph out of the bloodstream and back, and say what a node does. Five: tell antigen from antibody, and active immunity from passive.

Three combining forms open the unit, and they name three things that get run together. Lymph is the fluid. A lymph node is the structure that filters it. A lymphatic vessel is the tube it travels in. Each entry's warning exists to keep those three apart — and the third has a second job, because the vessel root it is built on came from the cardiovascular unit and names a blood vessel on its own.

The fluid itself.

MedTerm 0481 lymph/o: Lymph

The combining form lymph slash o names lymph, the clear fluid draining from tissues into the lymphatic vessels. Lymphoma is a tumor of lymphatic tissue, built on the suffix oma from Unit Two. Lymph is a fluid distinct from blood, though the two systems connect.

The structure that filters it.

MedTerm 0482 lymphaden/o: Lymph Node

The combining form lymphaden slash o names a lymph node, a small structure filtering lymph. Lymphadenopathy is disease of the lymph nodes, on the suffix pathy from Unit Two. Lymphaden names the node; lymph alone names the fluid passing through it.

The vessel it travels in.

MedTerm 0483 lymphangi/o: Lymph Vessel

The combining form lymphangi slash o names a lymphatic vessel. Lymphangitis is inflammation of a lymphatic vessel. Angi slash o on its own, carried forward from the cardiovascular unit, names a blood vessel — the added lymph specifies which kind of vessel is meant.

Three organs and three combining forms, each attached in the book to a Unit Two suffix you already own. The spleen filters blood and stores lymphocytes, the thymus is where certain immune cells mature, and the tonsils are lymphatic tissue at the back of the throat. Two of the three are spelled differently in the combining form than in the ordinary English word, and both warnings say exactly how.

The blood filter.

MedTerm 0484 splen/o: Spleen

The combining form splen slash o names the spleen, the organ filtering blood and storing lymphocytes. Splenomegaly is enlargement of the spleen, on the suffix megaly from Unit Two. Splen has one e in the combining form. Spleen, the English word, has two.

Where immune cells mature.

MedTerm 0485 thym/o: Thymus

The combining form thym slash o names the thymus, the gland in which certain immune cells mature. Thymectomy is surgical removal of the thymus, on the suffix ectomy from Unit Two. Thym slash o also names the mind in a small number of older terms.

Tissue at the throat.

MedTerm 0486 tonsill/o: Tonsil

The combining form tonsill slash o names a tonsil, lymphatic tissue at the back of the throat. Tonsillitis is inflammation of the tonsils, on the suffix itis from Unit Two. Tonsill takes two l's in the combining form, though the English word tonsil takes one.

Four entries turn from the plumbing to the response. Two combining forms name immunity itself and the act of engulfing, and the second of those is borrowed by the digestive unit later with its meaning unchanged. Then come the only two suffixes this unit contributes to the course, and both are defined against something already in hand: globulin against globin from the blood unit, phylaxis against a prefix that will reverse it before this unit is over.

The response itself.

MedTerm 0487 immun/o: Immune

The combining form immun slash o names immunity, the body's protection against disease. Immunology is the study of the immune system, on the suffix logy from Unit Two. Immun slash o names the protective response, not any one organ producing it.

Eating, and engulfing.

MedTerm 0488 phag/o: Eating or Swallowing

The combining form phag slash o names eating, swallowing, or engulfing. A phagocyte is a cell that engulfs and destroys foreign material, built on cyt slash o from Unit Four. Phag slash o appears in immune terms and in digestive terms with the same meaning.

The first new suffix.

MedTerm 0489 -phylaxis: Protection

The suffix phylaxis names protection or guarding against what its root identifies. Prophylaxis is a measure taken to protect against disease before it occurs. Phylaxis names protection, and a prefix placed in front of it can reverse that sense entirely — as one term later in this unit does.

The second new suffix.

MedTerm 0490 -globulin: Protein

The suffix globulin names a class of proteins, and in immune terms names the antibody proteins. An immunoglobulin is an antibody protein. Globulin names a protein family. Globin alone, numbered in the blood unit, names the oxygen-carrying protein of red cells.

Two anatomy entries. The first traces a one-way circuit: fluid leaves the bloodstream into tissues, the lymphatic vessels collect it, and it is returned to the bloodstream. What carries is the thing the system does not have. There is no pump, so the valves numbered in the cardiovascular unit and ordinary muscle activity are what move lymph at all.

The circuit.

MedTerm 0491 Lymph and Its Circulation

Lymph is fluid that leaves the bloodstream into tissues, is collected by lymphatic vessels, and is returned to the bloodstream. It travels in one direction only, toward the heart. The lymphatic system has no pump: movement depends on muscle activity and on vessel valves, taught in the cardiovascular unit.

The filter on the line.

MedTerm 0492 A Lymph Node

A lymph node is a small structure along a lymphatic vessel that filters lymph and houses immune cells. Nodes cluster in the neck, armpit, and groin. An enlarged node is described as lymphadenopathy, a term that names the finding rather than its cause.

Four entries in two pairs, and the book numbers each pair adjacently with links running both ways. Antigen and antibody name opposite sides of a single event and differ by three letters. Active and passive immunity differ by who made the antibodies. Neither pair can be learned one member at a time, because each term's definition contains the other one.

What provokes the response.

MedTerm 0493 An Antigen

An antigen is any substance the body recognizes as foreign and responds to. A protein on the surface of a bacterium can act as an antigen. The term carries anti, the Unit Three prefix meaning against. An antigen provokes the response; a different substance carries it out.

What carries it out.

MedTerm 0494 An Antibody

An antibody is a protein produced by the immune system that binds to a specific antigen. An antibody produced against one antigen does not bind another. Antigen and antibody differ by three letters and name opposite sides of the same event.

Protection you make.

MedTerm 0495 Active Immunity

Active immunity is protection produced when a person's own immune system makes the antibodies. Recovering from an infection can produce active immunity to it. Active immunity develops over time and tends to last, which is what separates it from the form named next.

Protection you receive.

MedTerm 0496 Passive Immunity

Passive immunity is protection produced when antibodies made elsewhere are transferred to a person. Antibodies passing from parent to infant give passive immunity. Active immunity is made by the recipient; passive immunity is received ready-made, and it fades.

Two entries, and both describe the immune system working against the person who has it. An allergy is a response to a substance that is harmless in itself, which is exactly what separates it from an infection. Anaphylaxis is that response at whole-body scale, and its name is a demonstration of the unit's own suffix: a Unit Three prefix placed on protection to mean protection's opposite.

An exaggerated response.

MedTerm 0497 An Allergy

An allergy is an exaggerated immune response to a substance most people tolerate. An allergen is the substance provoking the response. An allergy is a response to something harmless in itself, and that is what separates an allergy from an infection.

The suffix, reversed.

MedTerm 0498 Anaphylaxis

Anaphylaxis is a severe, rapid, whole-body allergic reaction. The term joins the prefix ana, numbered in Unit Three, with the suffix phylaxis, protection, and names its opposite. The term names a reaction and nothing else. What follows one belongs to clinical training.

Two entries close the unit and neither introduces a new root. The first walks four builds and names the join at each one, including two terms that differ only in the first letter of their suffix — which is the letter that decides whether the combining vowel appears. The second decodes ten terms suffix first, and its own closing note is the finding worth keeping.

Four builds, each join named.

MedTerm 0499 Building Lymphatic and Immune Terms

Building a term here means selecting the combining form, then the suffix, then applying Unit One's joining rules. Lymphaden plus itis: a vowel suffix, so the bare root links it — lymphadenitis, inflammation of a lymph node. Lymphaden slash o plus pathy: a consonant suffix, so the combining form links it — lymphadenopathy. Splen slash o plus megaly gives splenomegaly; immun slash o plus logy gives immunology. Builds one and two differ only in the first letter of the suffix, and that letter decides whether the o appears.

The capstone. Ten terms, suffix first.

MedTerm 0500 Capstone: Ten Lymphatic and Immune Terms Decoded

Ten terms decoded suffix first, using the word parts of Units Two through Eight. Oma on lymph gives lymphoma, a tumor of lymphatic tissue. Itis on lymphaden and on lymphangi gives lymphadenitis and lymphangitis. Megaly and ectomy on splen give splenomegaly and splenectomy; ectomy again on thym and on tonsill gives thymectomy and tonsillectomy. Logy on immun gives immunology, cyte on phag gives phagocyte, and globulin on immun gives immunoglobulin. Five of the ten used ectomy or itis, both numbered in Unit Two. This unit supplied only the roots.

Five things to carry out of Unit Eight. Lymph slash o names the fluid, lymphaden slash o names the node that filters it, and lymphangi slash o names the vessel it travels in. Angi slash o alone, from the cardiovascular unit, names a blood vessel — the added lymph is what narrows it. Splen slash o is the spleen with one e, thym slash o is the thymus where certain immune cells mature, and tonsill slash o is the tonsil with two l's. Immun slash o names the protective response rather than any organ, and phag slash o names engulfing, with the same sense in immune and digestive terms. Phylaxis names protection, and globulin names the antibody proteins as against globin, the oxygen-carrying protein of red cells. An allergy is an exaggerated response to something harmless in itself. Anaphylaxis is that response whole-body, its name built by placing a Unit Three prefix on protection to mean its opposite. Lymph leaves the bloodstream into tissues, is collected by lymphatic vessels, and is returned. It moves in one direction only, and there is no pump — muscle activity and vessel valves do the work. A node along the line filters lymph, and an enlarged one is lymphadenopathy, which names the finding and not its cause. An antigen provokes the response and an antibody carries it out, three letters and opposite sides of one event. Active immunity is made by the recipient and tends to last; passive immunity is received ready-made and fades. Unit Nine opens the respiratory system, which cites this unit and Unit Seven the same way this one cited Unit Seven.