This Science quiz is called 'Anatomy - The Lymphatic System' and it has been written by teachers to help you if you are studying the subject at middle school. Playing educational quizzes is a fabulous way to learn if you are in the 6th, 7th or 8th grade - aged 11 to 14.
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In middle school you'll study the cardiovascular system, which is also referred to as the circulatory system. The cardiovascular system is made up of the heart and the blood vessels or arteries and veins. It is the process in which blood flows through the body in order to circulate oxygen to the tissues and organs. Even before studying this system you probably had heard about it because most people are aware of it. However, another very important and vital system of the body is one that you might not have heard of, at least not to the same extent as you have heard of the cardiovascular system. That other system is known as the lymphatic system.
The lymphatic system consists of a group of organs and tissues.
Among the organs are the lymph nodes, lymph veins, the thymus, the tonsils, the adenoids, the appendix and the spleen. These organs and tissues work to collect the excess fluid of the body and return that fluid to the blood. In addition, the lymphatic system helps the body fight against pathogens.
Lymph nodes are small, bean shaped masses of tissue that remove pathogens and dead cells from the lymph. The nodes are concentrated in the armpits, neck and groin area. In the human body there are somewhere between 600 and 700 lymph nodes.
The thymus is a thin, flat gland. The thymus secretes the hormone thymosin which then stimulates the activity of the lymphocytes. It also produces thymic or T-cells or T-lymphocytes. The thymus is far more prevalent in children than it is in adults. It reaches its full size during puberty and then it decreases in size until, in most adults, it completely disappears, being replaced by fatty connective tissue.
The tonsils are small, rounded masses of lymphatic tissue located in the pharynx and in the passage from the mouth to the pharynx. The tonsils help the body to fight against infection.
The adenoids are a single clump of lymphoid tissue located in the back of the nasal cavity, above and behind the uvula. It looks like a piece of teardrop-shaped tissue that hangs down between the tonsils. At around the age of 5 the adenoids begin to shrink in side and disappear during the teen years.
The appendix sits at the junction of the small intestine and large intestine. It is a thin tube about four inches long and sits in the lower right abdomen. The purpose of the appendix is still unknown but it is believed that it acted, at one time in the history of man, as a storehouse for good bacteria.
The spleen is largest lymphatic organ and it stores and produces lymphocytes (a type of white blood cell that helps your body fight pathogens). The spleen is about the size of your fist and is purple in coloring.
Just as the heart depended upon blood vessels, the lymphatic system depends upon lymphatic vessels. The lymphatic vessels are large vessels that carry fluid and lymph to the capillaries. Lymph originates as plasma (the fluid portion of blood) and is a clear, colorless fluid containing white blood cells that helps rid the body of toxins, waste and other unwanted materials that is collected by both the lymphatic vessels and the lymph nodes. In turn, the lymph capillaries are the smallest vessels of the lymphatic system. Their purpose is to absorb some of the fluid and particles that flow between the body’s cells.
The lymphatic system is connected to every organ of the body. It is a type of internal trash collector system as it literally sucks up metabolic garbage, toxins and excess fluids that are found in every organ. If the flow in removing this excess fluid and toxins becomes clogged, the fluid will become thick and create a breeding ground environment for infections. Viruses, bacteria and parasites can become locked within the lymphatic system which then cause a multitude of physical ailments, degenerative diseases, swollen glands and even death.
As the lymphatic system is not connected to the heart, it relies on other activities to pump and circulate the fluid. The three most common methods of lymphatic circulation are (1) external massage, (2) muscle activity, and (3) vigorous exercise.
The lymphatic system is filled with millions of one-way valves. These valves allow lymph fluid to flow unidirectional or, in other words, upwards away from gravity.
Swollen glands is a symptom of having blocked lymph nodes. However, there are many other examples of illnesses of the lymphatic system. Among just a few of these are:
Eczema and other skin conditions
Loss of energy
High blood pressure
Low back pain
Ear or balance problems
There you have a brief review of the lymphatic system. Now it’s your turn to see just how much of the lymphatic system you can remember. Take a look at the following questions and see if you can locate the correct answer.