InPharm Tours

Prepared by Geoff Barnett

In any league table of the ten or so body systems ranked by level of public understanding, it's a fair bet that the lymphatic (or lymphoid) system would come some way down the list. Why this should be is difficult to say; maybe its complexity has something to do with it or perhaps Lymph Flows Breed Lymph Woes provides other clues. For example, it contends that the lymphatic system receives scant attention during our educational years and has a negative image because we're only made aware of it when things go wrong. This is an oddball site to say the least, but I tend to agree with its core message. What do you think?

Why not begin the main part of our tour by testing your baseline knowledge of the lymphatic system. Don't look for the answers at this stage but go straight to Human Anatomy and Physiology: the Lymphatic System and fill in the missing words. Although this is fairly basic stuff and it's not the most explicit test ever devised, did you, like me, find yourself resorting to guesswork with many of the questions and feel that you should have done better? Take heart! I'll ask you to repeat the test at the end of the tour and will be disappointed if your score doesn't show a marked improvement! Mind you, you'll have to ferret around some of the sites to find the answers.

Make a start on our educational journey at The Lymphatic System: Thymus which shows diagrammatically the layout of the major parts of the system: lymphatic vessels; bone marrow; lymph nodes (or lymph glands); thymus and spleen. For a more detailed anatomical representation, go to Atlas of the Body: the Lymphatic System and spot the missing lymph organs.

Let's now turn to what the system does. Two of its key functions are:

• Defence of the body against infection
• Collection of excess tissue fluid for return to the bloodstream.

We need to amplify these roles, but the first takes us into the field of immunology - one of the most complex of all medical subjects and dreaded by the majority of medical students. Fear not! The Immune System - An Overview is a well written site that pitches its content at just the right level for our purposes. Although the site is 5-years old and therefore in need of updating and ideally illustrating, the first two pages are the ones of direct relevance to our tour and would probably change little. Do take time to look up further sites on the remarkable thymus, perhaps exploring more fully the amazing process of thymic education. The second function is described at Lymphatic System. Here the style of the text, in the form of telegraphese stab points, is completely different to the previous site, yet it succeeds equally in communicating the information. The site benefits from excellent graphics, but I would prefer to see them larger, or capable of being enlarged when clicked.

Next, we'll proceed to a clinical examination of some of the diseases of the lymphatic system - a subject that's summarised as item 6 at Human Lymphatic System. Most of us have had tonsillitis at some stage in our lives, but although there are still 70,000 tonsillectomies carried out in the UK every year, surgery is no longer the standard treatment that it was before the days of antibiotics and more clearly defined indications. A US site, Tonsillectomy provides enlargeable illustrations and answers to all your likely questions about the operation, while My Tonsils! is a personal account of the procedure that includes before, during and after photographs, as well as one of an extracted tonsil.

The body has about 600 lymph nodes varying in size from microscopic to approximately 2.5 cm (1 inch) in diameter. Common areas where they can be easily felt, especially if enlarged, are in the neck, the groin, armpits and above the collar bone. Lymphoedema - blockage or dysfunction of the nodes or lymph vessels - is often a consequence of surgery and treatment for breast, prostate and reproductive organ cancers. This is a painful and often disfiguring disease characterised by excessive swelling that affects an estimated 150 million people worldwide. Click on Lymphedema: Effective Treatment & Management is Possible! to see photographs of this distressing condition.

The usual cause of elephantiasis, a horrendous disease characterised by an enormous enlargement of the infected area, is Wuchereria bancrofti, a threadlike filarial worm transmitted by mosquitoes. Damage is caused directly to the lymphatic system and through the immune system's response to the worms' presence. Read at Free Drugs to Wipe Out Disfiguring Disease how SmithKline Beecham have agreed to donate their anthelmintic Eskazole (albendazole) free of charge to the WHO until the disease has been eradicated.

At about 13 cm (5 in) long and weighing roughly 200 g (7 oz) in adults, the spleen is the largest of the lymphoid tissues. Normal Spleen is a good example of a 'how not to' site. For a start it's an orphan file - there are no internal or external links - and I can't remember how I arrived there. I'm fairly sure I clicked on 'normal spleen' at the previous site, but as the photograph is uncaptioned, you'll have to take my word for it. (More correctly it should say 'sectioned normal spleen'.) If that's not enough, the scale is unlabelled, but having given you the dimensions of a normal spleen, I'll let you decide what units should have been shown. Splenomegaly, abnormal enlargement of the spleen, may occur in association with a wide variety of diseases, and its weight can increase ten-fold. See a 5-minute video of the removal of such a spleen at Hand-Assisted Laparoscopic Splenectomy - a Smith & Nephew sponsored site.

Now, why don't you return to the opening test at Human Anatomy and Physiology: the Lymphatic System and try to complete the missing words again, checking your answers by clicking Jump to the Ch 21 Notes. Better results this time I trust!

To make any comments on this article, or to ask a question of the author, please contact the publisher. If you would like to submit an article please subscribe to our PL Intelligence service.

The opinions expressed in the articles published in this section do not necessarily reflect those of Pharmalicensing or UTEK Corporation. No actions including proposals to or agreements with other companies should be taken by any reader without obtaining specific business or legal advice. Neither the publisher nor the authors accept any liability for any actions or activities undertaken by any reader or other third party as a consequence of these articles or for any errors or omissions therein.