The Role of the Lymphatic System
Sarah Knotts
Product Management Coordinator
May 2017
The lymphatic system plays an important role in maintaining the body’s immunity against illness. It is made up of many vessels, tissues, and organs, including lymph nodes, tonsils, and the spleen. The cardiovascular system works closely with the lymphatic system to filter foreign substances through these tissues so they can be removed.
Lymph organs house a large number of white blood cells that help protect the body from invading microorganisms and other infectious agents. These white blood cells attack, deploy antibodies, and release histamines when a foreign substance enters the body. Unfortunately, viruses, bacteria, and other pathogens are not the only invaders the body will attack.
The allergic response
Allergies are an overreaction of the immune system to foreign substances. This type of response is known as an allergic response and can range from moderate to life-threatening. The steps involved in a typical allergic response are outlined below.
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| 1st Exposure to an Allergen The first time the body is exposed to an allergen, it is flooded with white blood cells, and the immune system starts producing antibodies to fight the response. |
2nd Exposure to an Allergen The second exposure to an allergen results in an increased production of antibodies. |
Histamines Are Released White blood cells release chemicals, such as histamines, that result in an inflammatory response. |
Levels of allergic reactions
The body can experience several levels of allergic reactions:
- Allergic rhinitis occurs when the body is exposed to allergens that irritate the lining of the nose and throat. Common allergens include pollen grains, dust mites, and pet dander, which can cause sneezing, coughing, and itchy, watery eyes.
- Food allergies are caused by an over-reactive immune response to certain foods, such as nuts and seafood. Symptoms of food allergies may occur as soon as the body is exposed to the food, or they may take several hours to develop. Skin rashes, swelling of the mouth and throat, vomiting, and diarrhea are just a few of the symptoms someone might experience.
- Anaphylaxis results from an extreme sensitivity to an allergen. This type of immune response involves the entire body. Massive amounts of histamines are released, causing a drop in blood pressure. This response can also cause airways to become restricted. Although this type of reaction is rare, it is potentially fatal.
The graph below illustrates the body’s primary and secondary responses to exposures to a foreign substance. The body’s response to a secondary exposure is faster and greater than to the first, whether the substance is a pathogen or an allergen.
Questions
Describe the steps of an allergic response.
Name some common allergens for each of the 3 levels of an allergic reaction.
Answer this question on your own:
What kinds of medications can be given to treat the different types of allergic reactions? Why?
