InterActive Medical Terminology

Based on the best selling text: An Introduction to Medical Terminology for Health Care (Fifth edition) by A.R.Hutton published by Elsevier Ltd

Unit 6: The Lymphatic System and Immunology

The interactive learning material in this unit is arranged into four sections. Click on a section and scroll down the page completing the exercises in the sequence they are presented:

• Section 1: Introduction
• Section 2: The Lymphatic System
• Section 3: The Immune Response
• Section 4: Self Assessment

Click on a section and scroll down the page completing the exercises in the sequence they are presented.

Note: FlashCards for revision of this unit are at the end of Section 3.

A short list of abbreviations, pathological conditions, clinical procedures and laboratory tests associated with the lymphatic system is available from the:Word Check.

Section 1: Introduction

The lymphatic system consists of capillaries, vessels, ducts and nodes that transport a clear fluid called lymph. Lymph is formed from tissue fluid that surrounds all tissue cells and it performs three important functions:

Section 2: The Lymphatic System

First look at Anatomy Exercise 1 to see the position of the main components of the lymphatic system:

Anatomy Exercise 1

Notice in the anatomical drawings in Anatomy Exercise 1(Word Set 2) that lymph vessels become larger as they join together eventually forming two large ducts the thoracic duct and the right lymphatic duct that empty into the subclavian veins near the heart. The thoracic duct begins at a dilated vessel called the cisterna chyli.

Within lymph vessels and duct are valves that ensure lymph flows in one direction only. There is no pump but muscle tissue in the walls of larger vessels contracts rhythmically to keep the lymph flowing. In addition contraction of adjacent muscles squeezes the vessels helping to move the lymph.