Ms. Judith Dixon
Immune system - there are two main types of immune cells in the body. The T or thymus cell lymphocytes are under the control of the thymus. The thymus cells are found in the blood. They are important to the body’s defense against disease. (White blood cells) the cells are also found in bone marrow, lymph glands, and the spleen. In the early years of life the thymus’s main concern is to program the body to resist infection. It’s quite large in the infant, by puberty it shrinks in size. It grows quickly until age seven then it slows down.
The second immune cell lymphocyte is responsible for manufacturing antibodies to foreign substances. Bacteria, microbes, and viruses are considered to be foreign substances. An important mechanism of the T cell lymphocyte is to allow the thymus to develop only these cells which can attack outside cells or foreign substances. Ninety-five percent of the new types of lymphocyte that are made in the thymus are destroyed before they can reach the rest of the body. White blood cells are classified into three groups. Lymphocytes, polymorphs, monocytes. Lymphocytes make up 25% of the white blood cells in the body.
Polymorphs are made in the bone marrow. They make up 50-75% of the white blood cells.
Lesson Plan IV - Immune System
Objectives:
To tell the process of how the immune system works
Materials:
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overhead projector
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picture of the immune cells function copied on overhead paper.
Procedures
The students will go through the steps with teacher as she teaches the parts of the immune system. Each student will then produce his or her own drawing of how the process works.
Heart
The parts of the heart are the aorta, superior vena cava, pulmonary arteries, pulmonary vein, pulmonary valve, tricuspid valve, mitral valve, and aortic valve. The four chambers the right atrium, left atrium, right ventricle, left ventricle and the inferior vena cava. The heart is a large muscular organ. Its location is in the middle of the chest area. The valves ensure that blood travels in one direction through the heart by preventing backflow. Two or three leaflets close off then the blood has passed through. The mitral and aortic valves control the flow of oxygenated blood on the left side of the heart. The tricuspid and pulmonary valves control the passage of deoxygenated blood on the right. The atrium (left and right) is the two low-pressure pumping chambers of the heart. The hearts pump the blood to their corresponding ventricle chambers. The coronary arteries supply the heart muscle with the oxygen and nutrients it needs. There are three main arteries. Two parts are on the left artery and one part on the right artery. The arteries are like pipes. They carry the blood outwards from the heart to the tissues. The veins carry the blood on the return journey.
Veins
The veins are similar to arteries. They are distributed the same way. The difference however, is that a vein can have valves an artery does not. Veins are tubes of muscular and fibrous tissue. The vein has a wall that is divided into three sections, the outer layer, middle layer, and inner lining. Veins only contain a very then layer of muscle. The vena cava is the large vein by which the blood returns to the heart.
Respiratory system
The respiratory system consists of the lungs, diaphragm, and the upper respiratory tract (nose, mouth, larynx, pharynx and trachea.)
Nose
An organ used for smell; the pathway by which air enters the body through normal breathing. External nose comprises of bones and cartilage. Internal the nose is divided into two narrow cavities that go from the front to the back. There is a partition between the two parts called the septum. It’s made of bone and cartilage. It’s covered with a soft, delicate membrane called mucous membrane.
Throat
This area leads to the respiratory and digestive tract. The throat is divided into two parts, the pharynx and trachea, and the larynx. The pharynx is located at the back of the mouth; it extends a little down inside the neck.
Larynx
The larynx is the voice box through which we speak. The outer tissue layer continues with the lining of the mouth. The lining contains mucus-producing glands, which keeps the throat and mouth lubricated, which is necessary for eating the speaking. Pharynx has three sections:
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The nasopharynx - the palate closes off the nasopharynx when you swallow to prevent food being forced up and out of the nose. In the roof of the nasopharynx are the adenoids, which are two clumps of tissue. They are found predominantly in children.
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The oropharynx - part of the airway between the mouth and lungs. The squeezing actions of the pharynx muscles help shape the sounds of speech when come from the larynx. The oropharynx organs that are important us are the tonsils. They are two mounds of soft tissue. They are often linked to sore throats.
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The laryngeal -- the lower part of the larynx is involved with swallowing.
Trachea
The front part of the throat. It consists of hoops of cartilage that hold open elastic tissue. It’s lined with mucous membrane, which keeps germs and dust from backing up into the throat to be swallowed.
Lungs
The lungs fill most of the thorax. The right lung is larger than the left. The heart takes up more room on the left side of the lung. The lungs are held up by surface tension. It’s created by fluid produced by a thin lining around the lungs and chest wall. This holds the lungs open. When the chest expands the lungs are pulled out and the air is taken into the alveoli. As the body exhales the rib muscles relax gradually. If the body relaxes completely the lungs would spring back rapidly. When air gets between the lungs and chest wall the surface tension breaks and the lungs collapse. The lung is connected to the trachea by the bronchus and to the pulmonary blood vessels. In normal lungs, oxygen from the air is transferred to the capillaries that surround each alveolus. A person who has a lung disorder experiences air construction.
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Pneumonia - air sacs are filled with fluid
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Emphysema - the walls of the air sacs break down
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Asthma - muscular walls of the bronchioles are narrowed
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Bronchitis - bronchus fills with mucus.
Kidney
Each body has two kidney located on the back wall of the abdomen. On the inner side of each kidney is a tube called the urethra. It runs down the back of the abdominal cavity and enters the bladder. The tube that leads from the bladder is called the urethra. It contains thousands of filtering units, which are very tiny. The units are thousands of filtering units, which are very tiny. The units are also called nephrons. Each nephron can be divided into two important parts - the filtering or glomerulus’s and the tubule. The tubule part is where water and essential nutrients are extracted from the blood. The glomerulus’s is a knot of tiny capillaries. The capillaries have then walls. Water and waste dissolve in the walls and can pass freely across them, into the collecting system of tubules on the other. The collection of system drains into the bladder.
Nervous System
The nervous system enables all organs and other systems of the body to function. It’s the body’s communication and control center. The system consists of approximately fourteen billion cells called neurons. They allow us to feel different sensations such as heat, cold, and pain. The cells work through tiny chemical signals that send messages. The signals reach the brain and thus the body knows what to do. The brain and the spinal are central nervous system, which controls the main functions of the body. Smaller nerves branch out to the outer part of the body. It’s called the peripheral nervous system. This system connects to the central nervous system.
There are two divisions of the peripheral system the somatic and autonomic system. Somatic system plays a two-part role. First it collects information from outer stimulus from the sensory organs, which are the eyes. Secondly, it signals are transmitted through motor fibers. These signals come from the central nervous system. It then goes to the skeletal muscles, which causes movement in the body.
(Tevor, 1993)