Updated 04/21/2010

 The  Caduceus Club       

2005 – 2006
 
Curriculum Guide for Teaching Faculty

     The Caduceus Club of the John Locke Society of Greater Kansas City provides volunteer teachers to elementary schools in the Kansas City Metropolitan Area to teach 5th grade students about health and hygiene. These teachers are retired physicians who care about the welfare of children and wish to make a contribution to their education and development.
    The program consists of fourteen sessions held over the course of the school year. These sessions have been developed during use over the past eight years by several physician/teachers. The material in the current curriculum guide was written and edited by Keith Ashcraft, MD.

Copyright � 2004 by Keith Ashcraft,MD. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form (electronic, mechanical, photocopying, recording or otherwise) without prior written permission from the author.
Permission requests to photocopy portions for internal or personal use or to reprint this text in part or in whole for noncommercial uses must be submitted in writing to the author.

Caduceus Club

Table of Contents

Session 1 – Health:   Self Assessment 

Session 2 – Consumer Health 

Session 3 – The Circulatory System 

Session 4 – The Respiratory System

Session 5 – Nutrition and Obesity Prevention 

Session 6 – The Reproductive System 

Session 7 – Social Skills  

Session 8 – Learning to Handle Conflicts, Bullies, and Peer Pressure 

Session 9 – Blood 

Session 10 – Feelings and Communication Skills 

Session 11 – The Digestive System and the Urinary System 

Session 12 – The Nervous System 

Session 13 – The Skeletal System 

Session 14 – The Endocrine System 

SESSION 1
HEALTH, SELF-ASSESSMENT:

This is a time of my life when I must begin to make some decisions about how I will live and how I may eventually die.  It is a time to take a close look at myself and at the other members of my family so that I can make some predictions about what I will become if nothing changes in my life-style.  It is a time to realize that I can take control of some parts of my life that will help me grow in a healthy way and will help me become what I want to be.  It is a time to realize that I am a responsible person.

The first thing I must look at is my body size and shape.   Obesity is a condition where the body is too fat. I must realize that unless something changes, my life will be shortened by approximately 7 years just because of being obese.

Obesity is almost an epidemic in America, especially among children.  The usual causes are too many calories ingested (fat and sugar) and too little exercise.  Obesity increases the workload on my heart, my lungs, my knees and feet—all of which can cause me a lot of pain or shorten my life.  Obesity may be the cause of type II diabetes that can cause me to lose my sight, have skin ulcers and shorten my life.  I don’t want to be obese and I can control it.

My height is _________ inches.    My weight is ________ pounds.

According to the chart, my BMI is _________.

There are some health problems that I cannot control.  I cannot control having asthma, a physical deformity, or some inherited forms of heart disease for instance, but I can prevent a lot of other diseases that are caused by making bad life-style choices.  Using tobacco will do nothing to make my life better but it may cause heart disease and cancer.  Using drugs will affect my nervous system in ways that will cause me to make bad decisions including lying and stealing to support a habit.  Using drugs will make me associate with people who are often criminals.  Being in jail for drug related crimes will certainly shorten my life. 

Alcohol is a drug that, if used at all, should only be used in situations where I should not be responsible for driving a car or making important decisions.  I know that tobacco and most other drugs are much more addictive than alcohol but if there is a history of alcohol addiction in my family, I might more easily become an alcoholic. 

Sexually transmitted diseases (STD) are very common.  It is important that I protect my body and my health by practicing safe sex.  This means not having sex until I am old enough and responsible enough to live with the consequences. HIV/AIDS is an STD that is not curable and is a miserable way to die. 

I realize that keeping clean is the way to prevent many infections that can be just a minor inconvenience or may be more serious.  Colds are transmitted by hand-to-hand contact.  Hand washing before eating or during the season when colds are very common will reduce the chances that I will come down with the respiratory diseases that others have.   

Some diseases “run in a family” and are inherited diseases because of the genes I have inherited from my parents and ancestors.   These inherited diseases include some types of cancer, some types of heart disease, cystic fibrosis and others.  It is important for me to know what diseases have been common in my family.  Part of my health assessment is to know what those diseases are.  I should particularly know the cause of death of family members.  I should also realize that some of these diseases are preventable. 

Most diseases are acquired diseases and are related to the way I live.  Some of these may also “run in the family.”  Obesity is the most common familial disease because my family usually eats the same things.  These diseases are almost all preventable. 

Exercise and proper nutrition are keys to keeping my body in good shape.  I think I will choose a life-style where I live healthy because it will make me live happier and longer.   I can then live by example when I have a family that will make my health and theirs better.

� KODA

Revised 8/05

 SESSION 2:
CONSUMER HEALTH  

Your money, your choice:  What determines the kind of cereal you ask your parent to purchase?  Is it the TV ads on Saturday morning?  Is it the kind of kids you see enjoying a bowl of Frosted Flakes?  Is it Tony the Tiger or Count Chocula?  Could it be the label on the side of the box that tells you that the cereal is full of fiber, low in sugar and fat that you know are the best kinds of food to eat?  You are what you eat. If you eat wholesome foods you will likely be healthy.  If you eat excessive fat and sugar you will likely become fat and may develop diabetes. 

Labels tell you what is in the food that you are considering.  The Nutrition Facts are required to be listed on nearly all pre-packaged foods sold in the USA.  The serving size, calorie content, calories from fat, kinds of fat, sodium, potassium, sugar content, dietary fiber and protein contents are all listed.  It is very important to your health to pay attention to these nutrition facts and to eat foods whenever possible that are low in fat and carbohydrates, have reasonable fiber content and that do not contain excessive sodium.  For some people with diabetes, for instance, these choices may be a matter of life or death. 

Simple sugars make food and drinks taste good but they do almost nothing good to our body.  The most common simple sugar is Sucrose.  Complex carbohydrates (starches) are a much healthier source of energy.  If the sugar content of a cereal is half or more of the total carbohydrates, that cereal is not a healthy choice.  Dietary Fiber may be either soluble or insoluble, meaning that it may be absorbed by the intestine or just simply passed on through.  Soluble fiber often helps lower the cholesterol in your blood which is a good thing.  Insoluble fiber helps keep your bowel movements regular.  A cereal that contains more than 4 grams of fiber in each serving is considered to be good.  Because of taste, many cereals will contain a lot of sugar and nearly no fiber.  Stay away from these. 

Over-the-counter Medicines: If you have a cough or a runny nose you may want to see what the drug-store or supermarket has to offer for relief of your symptoms.  Most large stores will carry both the brand names of medicines as well as their own generic remedies.  The brand name may be twice the price of the generic yet you may be getting exactly the same medication.  Read the Labels.  You will find from the label that the brand name contains exactly the same active ingredient in exactly the same concentration as does the generic.  Learn to shop for the ingredients and not just for the name.   

Brand Names are the names that manufacturers put on products that make you think of their product when you go to buy something.  They use this name for advertising in print and on television.   You will eventually come to ask for a Kleenex when you really want a disposable tissue.  Other packaging of the same tissue may carry the name of the store that sells tissues—for example the tissue you could buy at Target would be less expensive but would really be the same tissue.  These labels are called generic—a term that comes from the family of item rather than the manufacturer.   

The makers of “brand names” are often the same makers of the generic forms of over-the-counter medications.  They simply depend upon the consumer to recognize the advertised brand name and to associate that with more “effective relief” or “faster action.”  This is especially true of the commonly used medications such as aspirin or Tylenol.   

Shopping for these kinds of things has been made easier by the use of “unit pricing.”  On the shelf label for generic and brand name items there is often a price related to the unit dosage of a drug.  This will help you in getting the best value for your money.  Remember, most of these items are identical to the point of having been made by the same company. 

Dietary Supplements:  For many years there have been supplements offered in stores that are touted as being wonderful in lowering cholesterol of making ingested fat pass on through your gut without being absorbed.  Many of these products are not effective and some may be dangerous to your health.  Here are some “Tip offs to Rip offs.” 

            A claim that a product is “natural” or “non-toxic.”

            Claims of “amazing results.”

            Promotions that use the words “Scientific breakthrough,” 

 “Miraculous cure.” “Exclusive product;” or “Not available in stores.”

Claims that a product is quick and effective cure for several          ailments.

           Claims of limited time offers.

           Products that require payment in advance.

           Claims of no-risk, money-back guarantees.  

Beware of foods labeled LITE because the word really has no definite meaning.  Lite foods simply mean that the manufacturer has reduced the fat or sugar content below what they formerly put in the food.  It may still be very unwholesome. 

Remember; be wary of things that sound too good to be true.  Most of the time they aren’t.  Read the labels whenever you are considering a purchase that might make a difference to your health.  

Vocabulary:

Sucrose

Complex Carbohydrates

Fiber

Active Ingredients 

Student activities: 

1.  Select the most wholesome food from an overhead of 3 labels of cereal.  

2.    Compare the prices of a Bayer Aspirin and Target Aspirin, show labels and emphasize unit pricing.

Revised 8/05

SESSION 3:
THE CIRCULATORY SYSTEM 

The function of the circulatory system is to transport (carry) materials to the places in the body where they are needed.  Every cell in the body needs oxygen and other substances such as nutrients, minerals, vitamins, hormones, and antibodies in order to grow and to function properly.    

The circulatory system is made up of a pump (the heart) that pushes blood through a network of tubes (blood vessels) to every part of the body.  The blood flows (circulates) in the same direction all the time like cars going around a racetrack.  The blood vessels that circulate blood away from the heart are called arteries.  The artery that takes blood to the lungs is the pulmonary artery.  The main artery that takes blood to the body is called the aorta.    

Arteries divide and get smaller and smaller as the leave the heart to distribute blood to all the cells of the body.  In order for the body’s cells to use materials from the blood for growth and for the blood to receive waste products from the cells the cells must be in direct contact with very thin, tiny blood vessels at the end of the arteries that are called capillaries.  They are microscopic in size.  It is through the walls of the capillaries where oxygen and nutrients are exchanged for carbon dioxide and waste products.   

After the blood has delivered its materials to the cells, capillaries will join together to form small veins that return the blood toward the heart.   The veins get progressively larger as they near the heart.  The veins that bring blood back from the lungs to the heart are called the pulmonary veins.  The large veins that bring blood to the heart from the body are called the superior vena cava and the inferior vena cava. 

The heart is composed of two pumps, side-by-side.    There is a receiving chamber and a pumping chamber on both the right and the left sides of the heart.  The receiving chamber (the right atrium) receives blood from the body. When the pumping chamber of the right heart (the right ventricle) relaxes, blood flows from the atrium into the ventricle.  When the ventricle contracts it pumps blood to the lungs.  The blood picks up oxygen from the lungs and becomes bright red in color.  This blood comes back to the left atrium from the lungs and then is pumped to the body through the aorta by the left ventricle.  There are 4 one-way valves inside the heart to keep the blood flowing in the correct direction. 

The first branches off the aorta are the coronary arteries that supply oxygen and nutrients to the heart muscle itself.  The cardiac muscle has the ability to beat on and on without tiring.  If the coronary arteries become clogged up the heart muscle may stop working entirely--a condition known as a heart attack.  Smoking, diabetes, a high fat diet are the major causes of heart attacks.   

Your resting heart rate is about 70 beats per minute.  By the time you reach 11 years of age your heart has already pumped over 433,,000,000 times and you can reasonably expect it to beat another two and a half billion times over your lifetime.  It will beat longer and better if you treat it well. 

Every cell in your body requires a continuous supply of oxygen (O²) delivered by the cardiovascular system.  Most cells in your brain will die if they are deprived of O² for more than 5 minutes. Other cells in your body can withstand being without O² for much longer periods but all of them will eventually die as well.  The muscle cells in the heart that pump the blood to your body will cease to pump if they are deprived of O².  When the heart muscle is getting to little O² severe chest pain will usually be felt.  This is called a Heart Attack.   

As the oxygen is delivered to the cells, carbon dioxide is transferred from the body’s cells to the blood.  The blood now is dark because it has little oxygen and a lot of carbon dioxide.   As the blood is pumped through the lungs, the red cells get new oxygen and the carbon dioxide is passed into the lungs to be exhaled with the next breath. 

The blood circulates through the body continuously from before you are born until you die.  A given blood cell makes the round trip about every 3-4 minutes delivering its cargo of oxygen to the body cells and carbon dioxide to the lungs.  When you exercise or get excited your heart speeds up and more blood is pumped to your body.   

The blood is pumped from the heart into the arteries under pressure.  Normal blood pressure in an 11-year-old child is about 100/60 and is expressed in millimeters of mercury.   Normal blood pressure in a healthy adult is about 120/80.  If the person has hardening of the small arteries in the body the heart has to pump at a much higher pressure and the blood doesn’t circulate as fast or as efficiently as it should.  This extra workload on the heart can cause the heart to fail and the person will develop swollen ankles and shortness of breath. 

 In addition to the blood vessels that supply blood to the body there is a network of small vessels known as the lymphatic system.  These very tiny vessels gather fluid that has leaked from blood vessels and return it to the vein near the heart.  The lymphatic vessels are the primary way for nutrients and fats to get from the intestine to the circulatory system.  The lymph vessels also filter their fluid through lymph nodes that help remove bacteria that have gotten into the body through breaks in the skin and from the intestine. 

Keeping your circulatory system healthy is not very hard to do.   Regular exercise helps your coronary blood vessels to develop for those times when your heart needs an extra boost.  Maintaining a healthy BMI by eating sensibly will reduce the workload on your heart. The diabetes that develops from obesity and smoking tobacco causes the coronary arteries to become clogged and will greatly increase your risk of having a heart attack.

Student Activities: 

1. Have each student draw a cutaway view of the heart and great vessels.  Show overhead as they do this. 

� KODA

Revised 8/05

SESSION 4:
THE RESPIRATORY SYSTEM

Mammals breathe by inhaling air and extracting oxygen from it.   The body system that we have to do the job of taking oxygen from the air and making it available to the body is called the respiratory system.  The respiratory system consists of the air passages and the lungs. 

The nose and the nasal passages are designed to allow the intake of air and to remove impurities that could be harmful to the lungs.  The mucus membranes that line the nose are designed to humidify and to warm inspired air. Smoke and some chemicals such as ammonia or chlorine are strong irritants to our respiratory system.  When humans take up the habit of smoking tobacco they must overcome the natural desire to avoid smoke that is an inherent protective mechanism.   

The Throat is a passageway for both air and food.   The epiglottis is a flap that rests up out-of-the-way most of the time while we breathe.  When we swallow the epiglottis turns down to cover the entrance to the larynx directing food and liquids into the esophagus.  If solids or liquids are aspirated (sucked into the airway) they produce a violent cough reaction to clear the airway.  If the food or other object is not coughed up it can block the airway and must be removed.   The Heimlich maneuver is a way of helping someone clear their larynx if they choke on a piece of food. 

The larynx (the voice-box) is located in the neck just below the throat.  It is the upper part of the windpipe or trachea.  The larynx is a cylinder that has a cartilaginous skeleton.  The cartilage prevents the airway from complete collapse during the process of inhalation.   It also forms a framework for the contraction of the vocal chords enabling speech and singing. 

The trachea or windpipe attaches to the lower end of the larynx and extends from the neck down to the middle of the chest where it divides into the right and left bronchi.  Each bronchus conducts air to its own lung and divides into progressively smaller air passages. The smallest air passages connect with sacs of thin lung tissue called alveoli.      

The cells that line the airway are specialized cells that trap dust or smoke particles, surround them with mucus and move them to the trachea by means of tiny hair-like fingers called cilia.  Normally we cough to bring up the mucus.  Smoking cigarettes paralyze the cilia and hampers the cleansing of the air passages.    The walls of the bronchioles and the small air passages contain muscular tissue that reacts to irritants in the air by contracting to protect the alveoli.  This reaction is called asthma. 

Each lung has hundreds of millions of alveoli for the exchange of Oxygen and CO₂.  The exchange of oxygen and carbon dioxide is virtually instantaneous.  This process is called respiration or breathing.  Each alveolus is surrounded by capillaries so the blood has close contact with the air in the alveolus.  It has been estimated that if all the alveoli were laid out in one "sheet" the area would equal about 70 Sq. Meters.  That is almost the same size as a standard classroom.   

The lungs reside within the chest cage.  The ribs form a relatively rigid structure to give the lungs room to expand.  The diaphragms do most of the work of breathing.  One diaphragm is located inside of the ribcage on each side.  When the diaphragm is relaxed it forms a dome shape within the ribcage.  When the diaphragm contracts its muscle fibers shorten and the diaphragm flattens.  This increases the volume of the chest cavity and air flows into the lungs--a process called inspiration.   Except for strenuous breathing the chest wall contributes very little to the process of inspiration.   

After the rapid exchange of gases within the alveoli, the diaphragm relaxes, rising to its dome shape within the lower chest cage.  The normal elasticity of the lung tissue forces air out of the alveoli through the airway in the process of exhalation.  The process is repeated over and over again for about 25,000 times a day.   The process of breathing is largely automatic and does not require our conscious effort. We can, with effort, hold our breath for a period of up to a minute. 

Many of the diseases that affect the respiratory system are related to environmental problems.  Smoking often causes cancer in the lungs.  Smoking also produces a disease known as emphysema (em-fi-sema)--a condition where the lungs lose their elasticity and the person must exert a lot of effort to exhale.   

Asthma is a constriction of the smaller airways in response to irritants in the air. Sometimes the asthmatic response is of an allergic nature and sometimes asthma results from irritants in the air that we breathe.  .  Second hand smoke is a major factor in the development of asthma in children. Learning to avoid the asthmatic producing situations also helps people have fewer problems with asthma as they grow older. 

Infections of the upper part of the respiratory tract are often caused by viruses and are called "colds."  Most colds are transmitted by improper hand washing rather than by breathing the air around a person with a cold.  When a person with a cold coughs or sneezes they will transmit the viruses to their hands.  When you touch something they have touched or shake hands with someone who has a cold the virus is transmitted to you.  The virus gets into your body by way of your mouth.  When you are around someone with a cold, wash your hands often and well. 

.    We are also the only known species of animals that regularly injures their own respiratory tract by inhaling tobacco smoke or other substances that cause damage to the delicate tissues.   Without a doubt smoking of cigarettes is the most damaging thing you can do to your lungs.  Don’t even start!  Dying of pulmonary insufficiency or lung cancer is not pleasant.  By one disease process or another, smoking will shorten your life by about 7 years.

Student Activities:

1.   Have a student demonstrate the Heimlich Maneuver. 

2.  Have each student hold their breath, time them.

� KODA

Revised  8/05

SESSION 5:
NUTRITION AND OBESITY PREVENTION

Today more children, adolescents and adults are overweight and more are becoming absolutely obese.  This has become a major health problem.  What is the definition of obesity?  The Body Mass Index (BMI) is a ratio of your height to your weight and is an indicator of obesity.   Any BMI of 25 (that corresponds to the 85^th percentile) puts you in the “at risk for being overweight” category.   A BMI of 30 (95^th percentile) or more for a child means that you are obese. 

If you practice “good nutrition” your diet will consist of proteins, fats, carbohydrates (sugars), minerals and vitamins.  Eating a varied diet is good for you.  Water is essential for life and it is  important to drink water.    Milk is important for growing children.  

The incidence of obesity is increasing rapidly.  More than half of the people in the United States are overweight or frankly obese.  It is most important to realize that obesity is preventable.  If you are overweight or obese it is not because you have some tendency to be fat, it is because you eat more calories than you should.  A child is not obese because their parents are obese, they are obese because the whole family eats too much of the wrong foods. 

Many simple eating changes can help you lose weight.  Even a reduction of 100 calories per day will add up to a 10# weight loss in a year.  This can be as simple as cutting our one slice of bread or one soda each day.  The fat content of your diet should not count for more than 30% of your caloric intake.  

Calories:  Calories are the units of energy that your food contains.  One gram of fat contains 9 calories, one gram of sugar 5 calories, and one gram of protein 4 calories.  Children require more calories per unit of body weight than do adults because they are growing.  The caloric requirement for an eleven year-old should be between 2000-2400 calories per day.   

The more active you are, the more calories will be burned.   Walking at a brisk pace for 30 minutes 5x per week is really good exercise and will help you lose weight if you cut out some calories.   The less active you are, the more calories will be stored as fat.  It is very difficult to get your body to burn (use up) stored fat as an energy source unless you are literally starving.  Remember, a Big Mac, Large Fries and a Coke will provide you with 1200 calories or half your daily requirement. 

Guidelines for Good Nutrition: 

     Eat a variety of foods and in moderation, this is most important!

    You should not eat just because the food is there.  You should not waste food but cleaning up your plate is not necessarily a good thing.

     Maintain a BMI below 25

     Choose a diet low in fat, saturated fat and cholesterol

     Eat plenty of fruit, vegetables and whole-grain
products

    Use sugar only in moderation, be aware of the sugar content of what you eat and drink.

    Use salt only in moderation

   Drink water for at least half your daily fluid intake.  Drink more water in hot weather and when you are exercising.

   Avoid junk food

  Drink low fat milk

Learn the Food Pyramid and use it for your diet:

   Eat bread and cereals at least 4 x per day

  Eat vegetables and fruit at least 4 x per day

   Eat meat and eggs 2-3 x per day

  Use milk and dairy products 3 x per day 

You must look at the food pyramid from a healthy viewpoint.   For instance, whole grain bread is much healthier than white bread.  Some cereals contain a lot of sugar. Skim milk and low-fat dairy products are better for your body than whole milk and cream. 

Remember to read the labels on prepared foods such as cereal.

 Ask fast-food restaurants for their nutrition information, you’ll be amazed.

 Student Activities:

      1.  Draw a food pyramid.

SESSION 6:
THE REPRODUCTIVE SYSTEM

 The function of the reproductive systems of the male and the female are to produce a new human being.  This happens when a sperm from a man fertilizes an egg from the woman.  Humans are mammals so the young are born live and the mother produces milk for the baby. 

The male sex organs are the testicles and the penis.  Males have two testicles that reside in the scrotum because the sperm require a lower temperature to develop properly than would be found within the abdomen.  The testicles are egg-shaped and about 4-5 centimeters long in an adult man.   The scrotum is a muscular sac covered with skin that will relax to let the testicles hang lower when they are warm and will contract to lift the testicles near to the body when they are colder.  In addition to producing millions of sperm every day, the testicles produce testosterone, a male hormone that causes the development of male body characteristics when the male reaches puberty. 

The penis serves two purposes.  The most common one is as a passage for urine from the bladder.   The other is to deliver sperm through the same tube, the urethra, into the female vagina.  This happens when the erect or stiffened penis is inserted into the vagina and an orgasm occurs.  The sperm/fluid mixture is called semen.  The process of releasing the semen is called ejaculation.   

Sexual arousal in the male occurs with conscious thought.  The penis becomes erect when the venous blood is prevented from leaving and engorgement with incoming blood produces the erection.  Erection of the penis, however, occurs often during sleep without any sexual thoughts at all.  Sometimes during sleep both an erection and ejaculation occur in what is known as a wet dream. 

The female reproductive system consists of the vagina, the uterus, the fallopian tubes and the ovaries.  The ovaries are somewhat egg-shaped and are located within the lower abdomen of the woman.  When a girl is born, her ovaries already contain all the eggs that she will ever have.  As a girl enters puberty, the eggs begin to mature, usually only one per 28-day cycle.  The egg matures within a sac called a follicle, which will burst and the egg finds its way into the fallopian tube that connects with the uterus. 

Although the male produces sperm continuously, the female usually releases one mature egg per cycle and is therefore capable of having the egg fertilized for only a few days after the egg is released.  It requires only one sperm to fertilize one egg.  The sperm usually contacts the egg in the fallopian tube and the fertilized egg then continues downward to the uterus where it will implant in the soft, receptive lining (the endometrium) and begin the process of development into an embryo, then a fetus, and then a baby. 

Every 28 days, the female hormones will prepare the lining of the uterus for the implantation of the fertilized egg.  If fertilization does not occur, the lining of the uterus is discharged in a mixture of tissue and blood known as the menstrual flow or menstrual period.  The cycle then begins again with the maturation of another egg occurring about 12 days after the end of the menstrual period.  The onset of menstrual periods signals the beginning of the reproductive life of the female and the cessation of menstrual periods signals the end of the woman’s reproductive life.  The end of the menses is called the menopause and usually occurs at or about age 50. 

The lower part of the female reproductive tract is the vagina.  It serves not only as the place where sperm are deposited during sexual intercourse, but also as a birth canal for the passage of the baby from the uterus. The process of inserting the penis into the vagina and reaching orgasm is also called coitus or copulation.  When ejaculation occurs, the sperm begin a journey from the vagina into the uterus and up the fallopian tubes.  This trip usually takes about two hours.  All except the one sperm that fertilizes the egg will die.  A sperm moves by way of a tail that propels it along much like a tadpole moves in the water. 

Each sperm contains 23 chromosomes from the male that are added to 23 chromosomes from the female’s egg to produce an embryo that has the normal 46 chromosomes of a human being.  Each gamete (sperm or egg) has only one sex chromosome.  The sex chromosomes are called X and Y chromosomes.  A male has one X and one Y chromosome while the female has two X chromosomes.  All female eggs have an X chromosome.  Half of the sperm will have an X chromosome and half will have a Y chromosome.  If the sperm that fertilizes the egg is an X the baby will be a girl (XX) and if the sperm that fertilizes the egg is a Y the baby will be male (XY).  

An embryo is the early stage of development where organs and tissue become recognizable as the structures they are destined to become.   Starting from one fertilized egg/sperm combination, the embryo rapidly develops by mitotic division that ensures each cell has the requisite 46 chromosomes.  After several months, the embryo had developed to the point where it resembles a very small human being and becomes a fetus.  The fetus becomes a baby when it is expelled from the uterus.  Although born live, like many other mammals, a human baby is not capable of living without a great deal of support from its mother. 

The normal time for gestation (development from fertilization to birth) is 280 days or about 9 months.  Some babies are born early and may be premature.  If so they may require intensive life support in order to survive the early weeks of life.  Although a normal baby will weigh about 6-7 pounds at birth, healthy babies may weigh as little as 5 or as much as 11 pounds.  Shortly after giving birth a mother will begin to produce milk for the baby, a process called lactation.   Milk production will stop after a few days when the mother stops breast-feeding the baby.

Vocabulary:

Testicles                          Ovaries  

Penis                               Sex Chromosomes

Vagina                             Embryo

Uterus                                  Fetus

Fallopian Tubes                       Lactation                  

Gestation

� KODA

(Revised 8/05)

SESSION 7:
SOCIAL SKILLS

There have been “rules” for getting along peaceably with people for thousands of years.  Many of these rules were made into laws by which people formed “societies” so that they could live and work in groups.  Most of these laws required respect for authority (parents, teachers, “the law,” etc.) and most could be simplified by urging people to “treat others as you would like to be treated.” 

MAKING AND KEEPING FRIENDS:  Having friends is an important part of life.  It does not matter if you have a lot of friends but it matters a lot that you have some close friends.  A good friend should demonstrate eight core values:

1.       Compassion (caring) about you

2.       Fairness, sharing with you

3.       Bravery, standing up for what is right

4.       Respect for you and for others

5.       Responsibility or dependability

6.       Wisdom, making good choices when there are decisions to      be made.

7.       Truthfulness or honesty

8.       Optimism about the future

You will be faced with making choices about your behavior when it comes to making and keeping friends.  You want friends who are fun to be with and who do the right thing.   

GETTING ALONG WITH OTHERS: There are some social “skills” that you should practice in order to get along with others at school or work or in the family.  They are much like the values necessary for developing friends--if you make them part of your life, you’ll get along very well.  You will make a “first impression” on everyone you meet, make it be a good impression.  The social skills are:

1.       Introduce yourself with a smile

2.     Make sure you learn the name of the person you are meeting

3.     Make eye contact when someone is talking with you

4.       Be a good listener, most people like to talk

5.       Be polite.  Say please and thank you appropriately.

6.     Don’t be afraid to compliment someone when it is appropriate.

7.       Accept criticism from your teachers with eye contact and understanding

8.       Apologize when you have made a mistake.

9.       Follow instructions.  This means listening to explanations.

10.   Don’t be pushy in trying to get the teacher’s attention

11.   Disagree politely when you disagree

12.   Volunteer if you think you can help.

13.   Share.  If you play fair, others will too.

MAKING THE MOST OF YOUR FAMILY: Family relationships are very important in our lives.  Although very few families are like the TV families, your home should be the place where you can find shelter, food, a safe place to sleep and the people who will meet your emotional needs.  Some, maybe even many, families don’t always live together and don’t always make you feel good all the time.  You can contribute to the attitude of the family just the way you contribute to the friends that you have or to the school that you attend.  Practicing the social “skills” listed above is most important in the family.  Politeness, respect, listening and loving are most important in family life.   

The best families are not necessarily the families who have the most “things” or the best house.  The best families are those that hug and kiss and demonstrate affection for one another.   The best families are those that love you no matter what you may have done.  Being pleasant and helpful allows others in your family to do the same thing.  Families work best when everyone looks after their own things and when all contribute to the work around the house.      

Sometimes, however, family members abuse each other.  Abuse can be described as an action that injures another person.   Abuse doesn’t always mean physical violence.  Emotional abuse can be just as traumatic as hitting a person.  Often abuse is a “closely guarded secret” in a family that only makes things more difficult.  If you are abused as a child, you are likely to treat your children in the same manner.  It is important that this pattern of abuse, called a “cycle,” is not passed on.  If you are being abused it is important that you ask for help from your teacher or school counselor. 

STRESS MANAGEMENT: Stress is the worried feeling that you get when things just aren’t going right.  Lots of adults don’t think kids have stress but that is not true.  Things may not be going well in the family or in school or on a team.  Often kids feel stress in their belly—developing a stomachache when you know that school is likely to be unpleasant that day.  Adults demonstrate stress by having a headache, losing their appetite or by overeating.  Stress can be good like when it causes you to really try to do a good job or do well on a test.  When you feel the bad kind of stress there are some things you can do to relieve the stressful feelings.

     First, try to recognize the cause of your stress.

    Talk about your feelings with somebody you trust

    Take your mind off the problems if you can

   Write down how you feel and what might make you feel better

   Play with a pet if you have one but don’t kick the dog if you’re angry

   Do a chore that you know you need to get done (homework, reading)

   Ask for a hug or a kiss from your parents

There are bad things you can do when stressed

   Smoke a cigarette or marijuana

   Drink alcohol

   Become angry or violent

   Overeat

   Do something dishonest

Everybody feels stress of some sort every day.  Learn to handle it appropriately!

 � KODA

(Revised 8/05)

SESSION 8:
LEARNING TO HANDLE CONFLICTS, BULLIES, AND PEER PRESSURE

CONFLICT RESOLUTION:  A conflict is a disagreement or argument.  Resolution is the way that you get to a solution to the problem in the most satisfactory way.  Why is conflict resolution important?  It prevents fights and bad feelings!  Fights may be verbal (yelling) or nonverbal (hitting).  Fights are never really fun things and somebody usually gets hurt emotionally or physically.   Since we all will never agree on everything that comes up in our lives we need to know how to resolve conficts or disagreements without resorting to a fight. 

When you have a major disagreement or argument your breathing speeds up along with your heart rate.  Your blood pressure also goes up and often you will feel this as pounding in your head.  People sometimes say that an argument “makes their blood boil.”  When that happens, hurtful things are likely to be said or someone may actually hit another.  The best thing to do when you become angry with someone is to calm down before making any response.  Counting silently to 10 is a way to do that.  If the person with whom you disagree begins to shout or act agitated, encourage them to calm down.  You can then begin the process of conflict resolution.

1.   Remain calm, talk in a normal voice, no shouting

2.   Tell the person that you want to resolve the conflict peacefully

3.    Avoid blaming the other person or calling them names

4.   Agree on what the disagreement is about--define the argument

5.   Ask for the other person’s point of view on the disagreement

6.  Use “I” messages when you explain your point of view.   “I called you stupid because you tripped me.”

7.  Don’t be afraid to admit that you might have been partly at fault.

8.  Suggest a peaceful solution.  An apology beats a fight any day.

9.  When you agree on a solution, keep your end of the bargain

10.   If you can’t agree on a solution, ask an adult to help the two of you resolve your conflict peacefully.  Often a third party sees things better that either you or your opponent.

11.   Fairness is important.  Treat others fairly and they will do the same for you.

12.   Remember most conflicts will have been forgotten by the next day, so don’t hold a grudge

You will have conflicts almost every day of your life.  Learn to handle them peacefully.

DEALING WITH BULLIES:  Bullying is very common on the school bus, at recess and after school.  Most bullies are not very happy with themselves as people and try to make you notice them by intimidation (scaring you), physical violence, or name-calling.  Bullies often are victims of bullying by older siblings or parents and feel that passing it on is the right way to get their way.  Bullies can be very scary.  They may want to take your lunch money, your coat, shoes or back pack because they think this is the only way to get these things. 

How do you handle a bully?  In the first place, most bullies are cowards who will not try their bullying when there is anybody around that can come to your aid like a teacher or a bunch of your friends.  Sometimes it is not easy to get away from a bully but you should try.  Nothing makes a bully happier than seeing someone afraid.  When a bully comes on to you, if possible, you should:

    Avoid doing what they want you to do

    Make eye contact, look them in the eye

    Stand up as straight as you can, don’t slouch

Be as firm as you can be.  Tell them you don’t want to do    what they want you to do.

        Immediately turn your back and walk away

   Defend yourself as well as you can if the bully hits you and always report them to the teacher or the principal.

   If the bully has a knife or a gun, give them what they want and report them to the police ASAP

PEER PRESSURE:  Peer pressure is the pressure or influence someone near your age uses to encourage you to make a decision he or she wants you to make.  Peer pressure can be good when it encourages you to do something that is good and it can be bad when it is used to get you to do something that is illegal or dishonest or hurtful to someone else.  Many kids will give in to peer pressure to belong to a group or a gang.   

Sometimes your peers want you to join them in some activity that you may think is wrong.  They probably know that it is wrong but want you to join them so that they can feel better about doing whatever it is.  What are some unhealthy or risky behaviors your peers might want you to do?

         To fight another kid

         To shoplift

        To skip school

         Cheat on a test

         Copying someone’s homework

         To take a sip of beer or other alcoholic drink

         To smoke or use smokeless tobacco

         To use drugs

         To have sex

         To play with a gun

        To sneak out of the house at night

        To run away from home

Be sure you recognize peer pressure and do your best to avoid the bad influences. When peer pressure is used to encourage you to do something wrong you can 1) Say, “No, I don’t want to do that” and 2) Walk away, removing yourself from the temptation or situation.  Always ask yourself if your parents would like for you to be doing whatever is asked.   If the answer is no, don’t do it!

� KODA

(Revised 8/05)

SESSION 9:
BLOOD

About 8% of your body weight is blood.  Blood is made up of various cells suspended in liquid called plasma.   Blood, in normal circumstances, circulates in all your blood vessels throughout your body to deliver oxygen and nutrients to all of the cells and tissues; and to carry waste products from the body cells to the lungs and kidneys; to carry white blood cells to where ever they are needed to fight infection; and to carry platelets and the various clotting factors needed to control bleeding when blood vessels are injured.   

Plasma is the liquid part of the blood.  It is slightly yellow, straw-colored and comprises 55% of the volume of blood.  Plasma is mostly water in which red and white blood cells are suspended.   

Red Blood Cells are the most common cells in blood and comprise about 45% by volume normally.  The red cells distribute oxygen to and remove carbon dioxide from all the body cells.  Red blood cells contain hemoglobin—a protein used to carry oxygen (O₂).  Red blood cells will live for about 120 days in the body and are then destroyed.  The body recycles the iron to make new hemoglobin.  

White Blood Cells help the body fight infection.  The most common white blood cells are called neutrophils that work against bacteria that invade the body.  Neutrophils live for only about 1 day.   

The next most common white blood cells are called lymphocytes.  Lymphocytes help fight viral infections and also help your body’s immunity by making antibodies.   Antibodies give you long-term immunity when you are “immunized” against common childhood diseases. Lymphocytes live for a long time in the body—some may be with you for life.  

Platelets are very tiny cells that look like cockleburs under the microscope.  They provide the first step in stopping bleeding if there is a cut or other leak in a blood vessel.  Platelets live for about 10 days.  The ability of the body to stop bleeding is necessary for life.  As long as the blood is moving in the blood vessels it will remain in liquid form.  When the circulation stops because of blockage of a blood vessel, a clot can form that can be very harmful or even fatal if it then passes (embolizes) to an important artery. 

Blood Diseases:

Anemia is a condition in which there are fewer red blood cells (and hemoglobin) than normal.  An anemic person may have no symptoms but if the anemia becomes severe, the person develops symptoms as a result of insufficient O₂ being delivered to the tissues.   

Leukemia is a form of “cancer” in which the bone marrow produces white blood cells in an uncontrolled way

HIV-AIDS is a disease that interferes with the body’s ability to form immune antibodies.  It is transmitted from one person to another often by contact with an infected person’s blood.  Sharing needles for taking drugs is a common method of getting HIV. 

Hepatitis is another viral disease that can be transmitted by blood transfusions or by contact with the blood of an infected person.  Both HIV and Hepatitis can also be transmitted through other bodily fluids such as saliva or semen. 

Blood TYPES:  When people talk about their blood type, they usually mean the ABO typing system.  In this blood grouping system there are 4 types--A, B, AB or O.   Your blood type was inherited from your parents.   

BLOOD TRANSFUSIONS:  Blood transfusion can be life saving for patients who have suffered massive blood loss or who have had cancer treatments or surgery.  Blood must be matched by blood type so that the person getting the blood will not have a severe reaction to the blood.  There are many other blood group systems but none as important to blood transfusions as the ABO system.  Blood for transfusion can only come from people who care enough about others to go to the blood bank and donate their own blood.  Because blood can only be “stored” for about 8 weeks after it is donated.  Any person over 18 years old, in reasonably good health probably is an eligible donor. Donations can be made as often as every six weeks.  Some people have the misconception that blood donation may put the donor at risk for infections.  That is not true, it is impossible to get hepatitis, HIV or any other disease by being a blood donor.

Vocabulary:

Plasma                            Anemia

Red blood cells                   Leukocytosis

White blood cells                         Leukemia

Neutrophils                              ABO blood types

Lymphocytes                           Blood transfusions

Platelets 

(Revised8/05)

SESSION 10:
FEELINGS, COMMUNICATION SKILLS

FEELINGS:  We all experience many different emotions or “feelings” every day.  These include happiness or joy, sadness, anger, frustration, disappointment, embarrassment, loneliness, guilt, pride, and fear.  These are normal feelings that everybody has.  We need to be aware of our own feelings in order to be aware of the feelings of others.  Most people express their feelings verbally or non-verbally by the way that they look or the way that they act.   

Many of the feelings we experience are a direct result of the interactions that we have with our family members, teachers and peers.  If you can learn to identify your feelings, even anger, you can then learn to express them in a healthy way so that you don’t get into trouble. You can “hurt” a person’s feelings by what you say or by the way that you act toward them.  You don’t like to be hurt so don’t hurt others intentionally or on purpose.  Being good will make you happier than being bad. 

COMMUNICATION SKILLS:  We all communicate with each other verbally and non-verbally.   Both are very important and both help us to understand others and be understood by others.  The better you are at communication, the better you will be able to succeed in life.  As in all things, there are healthy and unhealthy ways to communicate.  Communication is really the sharing of feelings, thoughts, and information with another person.  It is one of the first things we learn to do.  A baby cannot communicate verbally but they learn very quickly to be able to let the parents know what they want or need.  Similarly, parents learn very quickly to know when the baby needs a diaper changed or is hungry or uncomfortable.  All this is non-verbal communication.   

As you grow your ability to communicate becomes more specific when it becomes verbal.  All through your life you will need to be able to express your needs and your feelings in a verbal way but your non-verbal actions also speak “a thousand words.”  Effective verbal communication involves using language appropriately.    

Verbal communications are messages you send to your listener by the way you select your words.  If you use “I” words, such as, “I would like for you to go with me” it is much gentler than if you were to say, “You come with me.”  “I am sad because we missed the bus” sounds better than “You are always late and you caused us to miss the bus.”  “I” messages are almost always healthier than “you” messages.  “You” messages almost always imply that you know the other person’s feelings and that you know best.  Speaking clearly and in a normal voice is very important if you wish to be understood. 

Nonverbal communication uses body language or facial expressions to convey feelings along with information.  When somebody looks you in the eye as they speak to you, you know that they are sincere.  When somebody asks you for something but will not make eye contact, you must wonder how much you can trust what they are saying.  When you look down as you speak, it means that you don’t feel confident in what you are saying.  Conversely, when someone is listening to you but not looking at you or is tapping their foot, you wonder how interested they are in what you are telling them.   When you sit with your arms crossed over your chest you are saying, nonverbally, to the person talking that you are “closed for business” and not interested in what they have to say.   

Active listening lets others know that you are indeed interested in what they have to say.  You make eye contact with the speaker and ask for clarification if you don’t understand.  You may find it helpful to restate the speaker’s comments in different words to make sure you understand what they are saying.  It is very difficult for you to communicate effectively with your parent while you are absorbed in a TV program or reading a book.  Active listening is the listening you do when you want to learn and it therefore most appropriate for schoolrooms.  Active listening is the non-verbal way of saying “I am paying attention to you.” 

Respect: Ignoring the speaker is very disrespectful.  It tells whoever is talking to you that you do not care what they are saying.  If you do this very often, people will stop talking to you.  Why should they waste their breath and effort to try to teach you anything?  You are saying, non-verbally, that you know everything you need to know about the subject being discussed.  These actions are usually based on ignorance rather than knowledge and you will, in the end, be the loser.  Successful people are usually eager to learn.  You can sort out what you really need to know in your profession later, but learn everything you can on the way to growing up. 

Communicating effectively with teachers, friends and family is not always easy but it is important.  Good communication helps family members stay close.  Families who share their feelings find it easier to understand, support and like each other.   Good communication also involves showing your care for others.  Tell your family you love them.  Don’t forget to also do this non-verbally with hugs and smiles.

 Remember:

1. Speak clearly and make eye contact with the person you’re talking to.

2. Use “I” messages whenever possible.

3. Don’t use “You” messages, especially to blame somebody.

4. Be aware of your own and other people’s “body language”

5. Use active listening always.  You will be surprised how much you learn.

6. Be respectful of others. 

Vocabulary:

Feelings                     Communication

Verbal                             Non-verbal

Active listening                Respect

� KODA

(Revised8/05)

. 

SESSION 11:
THE DIGESTIVE SYSTEM AND THE URINARY SYSTEM

THE DIGESTIVE SYSTEM 

In order for you to live and to grow you must eat.  The digestive system changes the food that you eat into small particles that can be absorbed into the blood stream and circulated around to the cells of the body for nourishment and growth.  The basic elements of all foods are protein, fat and carbohydrate.  Most foods also contain vitamins and minerals that your body needs. 

Digestion begins when you think about food and you begin to produce saliva.  Saliva contains enzymes that help digest sugar into small particles that eventually are formed into glucose—the only sugar that your body can use.  Chewing your food is a very important process in breaking food into more digestible pieces.  If you don’t have teeth it may be necessary to grind up your food in a food processor.  Chewing your food well helps your digestive tract with digestion.

When you swallow a bite of food or take a drink the epiglottis closes to protect your windpipe.  This is a very important protective mechanism for your lungs.  The food goes from the throat into the esophagus and passes rapidly into the stomach.  In the stomach the food is mixed very well with acid and with water to form a liquid that is thick like a malt.  When the food has been diluted it passes into the first portion of the small intestine known as the duodenum.   

The liver and the pancreas both have small tubes that connect to the duodenum by which more digestive juices and other enzymes are added to the liquid formed in the stomach.  These are primarily for the digestion of fat and the remaining sugar that has not been broken down as yet.   As the food passes into the next portion of the small intestine known as the jejunum the enzymes break protein into smaller particles called amino acids that can be absorbed through the wall of the intestine.   

The amino acids, fat, and sugar are absorbed in the last part of the small intestine, the ileum.  Many of the vitamins and minerals are also absorbed through the lining cells of the ileum into the lymphatic vessels that are concentrated in this area. 

The putting together of the proteins and fat that are absorbed is called metabolism.  A certain portion of the absorbed food is used just to keep your body functioning—keeping the heart and muscles active, keeping your brain working, keep your skin healthy and just keep you generally healthy.  This is called the basal metabolism.

The left-over liquid that now contains mostly the indigestible fiber in the diet enters the large intestine or colon.  The intestinal contents are still very watery at this point.   The job of the colon is to reabsorb water from this waste and make it into reasonably solid feces that are passed when you have a bowel movement.  There are many bacteria that live in the large intestine.  They are what give feces its distinct and unpleasant odor.  Sometimes the bacteria or viruses get out of control and you have diarrhea.

THE URINARY SYSTEM 

Your kidneys have two very important functions for your body.   They filter or clean a lot of material from the blood stream that can’t be eliminated through the lungs and they regulate the amount of water that makes up your body.  Water makes up two thirds of your body weight.  If you weigh 100 pounds, 67 pounds are simply water.  Most of this water is inside the cells of the body. 

You have two kidneys located in the back, upper part of your abdomen.  Because the kidneys are so important to the body they receive a lot of blood through very large arteries.   The blood goes first through the small nests of blood vessels called glomeruli in the surface layer of the kidney called the cortex.  A lot of the water portion of the blood is filtered along with wastes in the glomeruli.  This water/waste mixture is called the filtrate.  The filtrate then passes through a long tube attached to each glomerulus where the proper amount of water is reabsorbed into the blood stream.    

People who have diabetes produce a lot more urine because there is sugar in the filtrate that prevents the reabsorption of water.  Your kidneys produce about 45 gallons of filtrate per day but most of this is reabsorbed through the tubules so that you will only pass about 1 quart of urine per day. 

The urine passes from each kidney through a tube called a ureter into the bladder.  Your bladder is able to store a large amount of urine until you can get to the toilet to empty it.  Sometimes the urine in the bladder will get infected by bacteria from outside your body.  This occurs most frequently in girls because the tube from the bladder to the outside, called the urethra, is very short.  Most infections in young girls come from sitting in the bathtub.  It is important for girls to empty their bladder after getting out of the bathtub or the swimming pool.  Showers are generally a much healthier way to wash your body. 

Sometimes diseases such as diabetes will cause the kidneys to not work properly.  These people will develop swelling of the ankles and gain a lot of weight which is just extra retained water.  Many people with kidney failure are able to have the extra water removed by a process called dialysis.  Sometimes when dialysis doesn’t work well, the person will need to have a kidney transplant.   The donor of the kidney is often a family member.  You actually have four times as much kidney tissue as your body needs so giving one kidney to a person with kidney failure leaves you with plenty for yourself.

Vocabulary:

enzymes               amino acids                 glucose

esophagus              stomach              duodenum

jejunum                ileum                   colon

ureter                       bladder               urethra

� KODA

(Revised 8/05)      

SESSION 12:
THE NERVOUS SYSTEM

As you are reading this page, your nervous system is performing several different tasks, quickly and efficiently.  It is directing the muscles of your eyes to move back and forth across the page.  Your eyes are sending images of letters and words to your brain.  Your brain is forming letters into words and sentences and ideas.  Some of this information is stored in your brain for later recall while your brain is busy matching up the new information with what you already know.   Your nervous system tells your body how to hold the paper and how to turn the page.  Your brain may also be telling you that lunch hour is near and you realize that you are hungry.  All of these messages are being sent back and forth in your nervous system by electrical impulses. 

The central nervous system (CNS) is composed of your brain and your spinal cord.  The brain is made up of the Brainstem which keeps you breathing and provides for other vital systems to keep working without your thinking about them.  The Cerebellum is the part of your brain that has to do with balance and coordinated movement.  The Cerebral Cortex is the part of the brain where you think and receive conscious information.   There are billions of nerve cells in the central nervous system and there are many ways for them to connect with each other.  Learning is a process of setting up a network of nerve cells that will be able to hook up again when you recall a fact or an action that you have learned.   The more you use your brain, the more connections it will learn to make. 

The cerebral cortex is the most sophisticated part of your brain.  It is the place where learning happens and where memory (recall) occurs.  It is the part of your CNS that is most closely related to your moods or feelings.  There are certain bits of information that cross from one side of the body to the other side of the brain.   Each of us has a dominant side of the brain just as we have a dominant hand, eye and even foot.  If your dominant side of the brain is the left side, then you will be right handed.   If the dominant side is the right side, you will be left handed.  The left side of the brain is used for producing and understanding speech, reading, writing, and logical thinking.  The right side of the brain is used in appreciation of music, artistic ability, creativity and emotions.  When we sleep, the brain activity slows down, rests and prepares for another day. 

Although the brain is only about 2% of your body weight it uses 20% of the energy that you take in.  The brain uses only oxygen and glucose for energy.  If either of these is lacking the brain begins to slow down.  If your brain is deprived of oxygen for longer than about 4-5 minutes, the brain will stop functioning and will not start again.  If your blood sugar gets low because you are hungry, your brain will tell you to eat.   If your blood sugar gets really low your brain will cease to function and you will “black out.”  If a blood vessel that supplies blood to your brain becomes blocked, you will have a “stroke” that will cause a small area of your brain to die.  Most often this produces weakness, paralysis or difficulty with speech. 

The spinal cord is the large bundle of nerve cells that extend down your back and connect your body’s nerves and muscles to the brain.   The individual nerve cells are called neurons and some of them may be several feet long.  The neuron may receive information from several small branches called dendrites.  They pass them along by one branch called an axon to the dendrites of the next neuron in the pathway.  The axons and dendrites don’t actually touch each other.   Rather they transmit their message by a chemical process across the gap which is called a synapse.  The release of a chemical, called a neurotransmitter, from the axon of one cell across the synapse to the dendrite of the next cell happens in less than 1/10,000^th of a second.   

As the axons progress down the spinal cord, bundles will be given off to connect with a specific group of muscles or a specific organ.  These bundles are called the spinal nerves and usually take the name of the part to which they connect.  Sensory nerve fibers transmit impulses up the spinal cord to the sensory cortex of the brain to tell you where your feet or hands are positioned or what they are touching. 

Because the sensations are transmitted at such fast speeds, many of the protective reactions that the body has are called reflexes.  If you touch something hot, the sensory nerve impulse from your finger will make a connection with a motor nerve in your spinal cord causing you to jerk your finger away even before your brain “feels” the pain.  Doctors will sometimes test your reflexes by tapping just below your kneecap to see if your lower leg jerks normally. 

Injuries to the brain or the spinal cord are usually not reversible.   If a person has a severe head injury because they were thrown out of a car, they will often die or have severe disabilities.  This is a good reason for wearing a seat belt whenever you get into a car!  Injuries to the spinal cord from athletics or gunshots are often permanent and result in either paraplegia where the legs are paralyzed or in quadriplegia where the arms are also paralyzed.   Often you will see a football player who has suffered a broken neck claim that through sheer force of will, he will walk or run again.  Don’t believe it. 

You have learned about the dangers of using tobacco, alcohol and other drugs.  Part of the reason these substances are so dangerous has to do with the bad effects that they have on the nervous system.  Nicotine in tobacco is exceedingly addictive.  Once started, some people find it virtually impossible to stop using tobacco.  The addiction is felt in the brain but the bad effects of tobacco on the body are felt in the lungs and blood vessels.  Alcohol is a chemical that is poison to neurons.  It will actually kill some of the neurons if the blood alcohol level reaches certain levels.  Mostly, alcohol slows the transmission of information in the nervous system giving the person a false sense of being able to function normally.  Most of the automobile fatalities in teens result directly from the use of alcohol.  Narcotics likewise are depressants of the nervous system and with repeated use can disrupt many of the neural connections that allow us to function normally in life.  They are addictive in different degrees, which add to their danger. 

Your nervous system is a remarkable thing.  It is far superior to any species of animals that we know.   Protect it by using helmets when you ride a bike, seat belts when you ride in a car and by not poisoning it with things that you can do without.  Make healthy choices in your life.

Vocabulary:

Brainstem                         Cerebellum

Cerebral Cortex                      Neurons

Spinal Cord                          Addiction

� KODA (Revised8/05)

.

SESSION 13:
THE MUSCULOSKELETAL SYSTEM 

THE SKELETON is made up of more than 200 bones.  They range in size from the large bone in the thigh called the femur, to the three small bones in the inner ear, the malleus, the stapes, and the incus.  Because you have a skeleton, you are able to stand, sit, walk and run.  Your skeleton is inside your body and so it is called an “endo-skeleton.”  Endo means inside or within.  Some animals have an exo-skeleton.  Exo means outside.   An example of an exoskeleton is a shrimp, lobster, clams, oysters where the shell is the skeleton.  Some animals, like the turtle, have both endo and exo-skeletons.   

Almost all bones are hollow.  Some animals like the elephant and the hippopotamus have bones that are very thick because the animals are very heavy and need the strong bones to support their weight.   Birds, bats, and many fish have very light bones because they weigh less and allow the birds to fly better.  Some birds like chickens and emus and ostriches have heavy bones because they don’t fly.  Humans have some heavy bones like the bones of the legs and some light bones like the bones of the inner ear and nose that don’t have to support any weight.  The inside part of a hollow bone is filled with “marrow.” In the marrow are cells that produce white blood cells, red blood cells and the platelets.  

Bones are covered by a thin membrane called the periosteum.  The periosteum is the part of the bone that allows a bone to grow and to heal after it has been broken.   The periosteum has many nerve endings in it and when you break a bone the periosteum is what feels the pain.  

The place where one bone meets another is called an articulation.  Moveable articulations are called joints.  Several types of joints allow for different forms of joint motion at various locations in the body. Joints are held together by ligaments that extend from one bone to another.  The joint surface is covered with cartilage, a very slick tissue which keeps the surface of one bone from grinding away at the other bone making up the joint.  Sometimes injury or diseases affects the major joints to the point where they don’t work very well or don’t move without a lot of pain.  Joint disease is called arthritis.  Sometimes arthritis is due to degeneration of cartilage due to ageing (degenerative arthritis) and sometimes it is due to inflammation of the tissue holding the joint together (rheumatoid arthritis).  Some bones meet up against another bone but don’t need to move like a joint.  An example of this type of articulation is the skull, made up of several plates of bone that never move.  Some bones like the ribs have joints but are not expected to move very much where they join the spine. 

Some bones have a major function to protect as well as support the animal.  Examples of these bones are the skull, which protects the brain, and the spine, which protects the spinal cord.  Other bones have a major function in allowing the animal to move.  An example of these is the bones of the legs.  Some bones are designed to allow the animal to have very special skills.  An example of these bones is the wrists and the hands.  Without the special joints in the wrists and the hands, we would not be able to button our clothes or write or use a computer keyboard.  Although the hands and the feet have very nearly the same bones and muscles the hands are much more specialized.   

Regular exercise and a good diet are important for bone growth and development.  Milk is a major source of calcium that is essential for bone growth and continued bone strength as you get older.  As we reach middle age or older our bone density--a means of expressing bone strength--diminishes.   This leads to a condition called osteoporosis that can increase the risk of bone fractures.  It is important that you drink milk from infancy to about 21 years to prevent osteoporosis.

THE SKELETAL MUSCLES 

There are three kinds of muscle cells in our bodies.  The skeletal muscles make it possible for you to move your body. Smooth muscles control the activity of the intestine and the urinary tract.  The third kind of muscle, called cardiac muscle—your heart muscle—that  works nearly tirelessly from before we are born until we die.   

Muscles cause our bones to move in a purposeful way.  Muscles “originate” on the periosteum of one bone and “insert” by means of a tendon on another.  When the muscle contracts, the insertion holds steady and the tendon pulls the other bone in only one direction.  When the muscle relaxes the bone that was pulled often returns to its original position.  Many times there is a muscle on the other side of the original bone that pulls the moved bone back to its original position.  Because so many of our bones have “opposing” muscles we are able to move much better than if we relied on gravity to return bones to their starting postions.  If we didn’t have opposing muscle groups we wouldn’t be able to do push-ups or many of the things we do so often everyday. 

Muscles are composed mostly of protein. In order for your muscles to develop properly you must eat protein.  Much of our dietary protein comes from animal meat or fish.  Vegetables contain proteins as well.  Muscles utilize glucose (sugar) as fuel for contracting.  Glucose may be stored in the muscle but also comes to the muscle by way of blood circulation.  Not only is the supply of blood to a working muscle very important for supplying glucose, it is important that the blood flow be sufficient to remove the waste products (acids) that your muscles produce.  Build-up of acid will produce severe pain in the muscle.   

Exercise will improve the blood supply to muscles.  Exercise also increases the size of muscle cells but not the number of muscle cells.  Muscles enlarge in response to exercise.  Muscles will atrophy (waste away) if not used regularly.  Thus if you “pump iron” or run the muscles that you use in these exercises will get larger and stronger than if you don’t do these things.  A weight lifting program should be undertaken only under supervision of a coach or trainer.  Sitting and watching television will not help your muscles develop.  Like everything else in life, the way to good health is to do everything in moderation.  A moderate amount of exercise is the best way to ensure that you don’t become overweight.   

Muscles and tendons can be injured by overexertion.  The pain of an injured muscle is an indication that you should not put stress on that muscle for a period of time until the soreness goes away.  Improper lifting can cause the back muscles to become very tender.   It is always best to lift heavy objects by squatting and using your legs rather than your back to lift. 

Vocabulary:

Skeletal Muscle

Smooth Muscle

Cardiac Muscle

Articulation

Cartilage

Arthritis

Ligaments

Tendons

� KODA

(Revised 8//05

.

SESSION 14:
THE ENDOCRINE SYSTEM

There is a marvelous mechanism in your body that lets one part of your body know what another part needs or wants.  This system is called the endocrine system.  It mainly functions through the production of substances called hormones.  There are over 100 known hormones in mammals but we will talk about some of the more common and well known hormones that affect the way you grow and the way your body works.  Hormones are produced in glands and are almost always secreted or put in to the blood for distribution. 

The hypothalamus is a part of your brain located directly behind the bridge of your nose.  It is the part of the brain where many of the processes that affect your body begin.  The hypothalamus controls hunger, wakefulness, thirst, body temperature and your sex urges.  The pituitary (pit-to-i-tary) gland is located next to the hypothalamus where the six hormones are produced that control many of your basic body functions. 

1. Growth Hormone (GH) regulates the way your body grows.  Sometimes athletes take GH to make them stronger.  It is dangerous to do this without medical supervision. 

2. Thyroid Stimulating Hormone (TSH) is a substance that causes another gland, the Thyroid gland located in you neck, to produce several hormones that control your metabolism.   If you have too much thyroid hormone you will burn more calories than you should just to keep the basal metabolism going.  People will often be very jittery and lose weight if the thyroid gland is overactive.  People who have insufficient thyroid hormone will be “sluggish” and want to sleep a lot. 

3. Adrenocorticotropic Hormone (ACTH) stimulates the adrenal glands located above each kidney to produce cortisone that help your body fight stress and inflammation, regulate the amount of water and salt in the body, and determine whether you have body hair (male) or not (female). 

4. Luteinizing Hormone (LH) stimulates the testicles in males and the ovaries in females to develop and do their jobs. 

5. Follicle Stimulating Hormone (FSH) also acts on the testicles and ovaries. 

6. Prolactin (PRL) causes mothers to produce milk after they have a baby. 

The pituitary gland is sometimes called the “Master Gland” because it controls so many of the body’s functions but there are many hormones produced elsewhere that are not controlled by the pituitary.  

The intestines produce many hormones as do the liver and pancreas glands attached to it.  One of the major hormones that regulate sugar in our body is called Insulin produced by the pancreas gland.  When you eat sugar, the pancreas secretes insulin which causes the body to digest and store sugar in such a way that your blood sugar doesn’t go too high. When your blood sugar is low the production of insulin falls.  If you were to have too much insulin your blood sugar will fall below normal and you will become weak or jittery or maybe you would faint because the brain needs sugar to function.  Too much sugar will damage blood vessels all over the body leading to blindness, stroke, or kidney and heart failure.  The most common disease related to insufficient hormone in the body is Diabetes Mellitus.   

Type 1 diabetes is an inherited disease that begins in childhood and requires taking insulin injections every day.  Type 2 diabetes is also called “adult onset diabetes” although more and more children are being affected.  There may be a tendency for type 2 diabetes to run in families.  Whether this is inheritance or not is not known for sure.  It may be due to the observed fact that the family that eats the same unhealthy diet, gets fat together. It is caused by overeating, not getting enough exercise and being obese.  If discovered early, type 2 diabetes can sometimes be controlled entirely by losing weight and reducing the intake of sugar.   

Exercise is very important in the control of obesity.  Type 2 diabetes is one of the major health hazards to Americans because of the dietary habits that we have.  It is the major cause of kidney failure and blindness in older adults.  Often the blood vessels in the legs become blocked because of the diabetes and amputations are necessary.  It is almost entirely an avoidable disease if you practice healthy eating.   If you have a family member with type 2 diabetes it is most important that you get some good medical advice about your weight and your diet. 

The Parathyroid Glands are located behind the thyroid gland in the neck.  They control the absorption of calcium through the production of Parathormone (PTH).  Calcium is needed by your body to make bones and teeth. 

The adrenal gland also produces a number of other hormones from the inner part of the gland called the medulla.  These hormones are called Norepinephrine (NE),
Epinephrine (E) and Dopamine (Dop).  These hormones serve to transmit messages of danger within your nervous system, causing your heart rate to increase and your blood pressure to go up.   These are the hormones that get you ready to fight or make you want to run—the “fight or flight” reaction. 

As with all hormones, having just the right amount is “good” for your body and having too much or too little is “bad” for your body.  It is best never to take steroids or growth hormone unless prescribed by a doctor because the delicate balance of hormones in your body can be seriously disrupted. 

Vocabulary:

Hormones

Hypothalamus

Pituitary gland

Thyroid gland

Pancreas gland

Adrenal gland

� KODA (Revised8/05)