The Nervous System

“The human brain has more switches than all the computers on Earth. Researchers at Stanford developed a new imaging method that enables visualization in unprecedented detail of the myriad connections between nerve cells in the brain. “They found that the brain’s complexity is beyond anything they’d imagined, almost to the point of being beyond belief,” says Stephen Smith, a professor of molecular and cellular physiology and senior author of the paper describing the study. One synapse, by itself, is more like a microprocessor–with both memory-storage and information-processing elements–than a mere on/off switch. In fact, one synapse may contain on the order of 1,000 molecular-scale switches. A single human brain has more switches than all the computers and routers and Internet connections on Earth.
A typical, healthy brain houses some 200 billion nerve cells, which are connected to one another via hundreds of trillions of synapses. Each synapse functions like a microprocessor, and tens of thousands of them can connect a single neuron to other nerve cells. In the cerebral cortex alone, there are roughly 125 trillion synapses, which is about how many stars fill 1,500 Milky Way galaxies. These synapses are so tiny (less than a thousandth of a millimeter in diameter) that humans haven’t been able to see with great clarity what exactly they do and how, beyond knowing that their numbers vary over time. That is until now.
Researchers at the Stanford University School of Medicine have spent the past few years engineering a new imaging model, which they call array tomography, in conjunction with novel computational software, to stitch together image slices into a three-dimensional image that can be rotated, penetrated and navigated.”

Content: The Nervous System
Do we have electricity inside of us? Yes, we do. Ripples of electricity take messages to our brain. Electricity travels to the brain along cells called neurons and the brain gets the message and tells us what to do.

Where is our brain? Our brain is inside our head and is protected by the bones of our skull. The long chord that comes from our brain is our spinal chord and it is inside the vertebrae of our back. These bones protect the spinal chord. Nerve cells carry electrical signals to and from the spinal chord. All five of our senses are connected to our brain. The brain tells us to move or if we are touching something. The fastest brain message travels 360 mph!

The brain, spinal chord and nerves (31 pair of spinal nerves) make up our nervous system and control the actions and sensations of the whole body. The largest cells in our body are nerve cells. In the brain they are very small, but they can be as long as 4 feet in our legs. Point out the parts of the nervous system on the chart. The spinal nerves have 2 jobs; taking messages to the brain and reflexes.

Draw a picture of a neuron. There are 3 kinds of neurons: motor, sensory, and connector. We have 100 billion neurons in our body. The brain controls the whole body and tries to keep it stable (homeostasis).

What gives the brain energy? OXYGEN from the air we breathe gives the brain energy. If the brain goes for 5 minutes without oxygen then it begins to die. If we learn something new, the brain grows and makes new connections!

When we are asleep the brain keeps our heart beating and our lungs breathing. We have a built in sleep-wake clock. Lack of sleep can hurt us because this is when the brain stores up chemicals it will need for the next day. In our lifetime we will sleep almost 30 years! Our brain uses a lot of energy (20%) and consumes a lot of oxygen (1/4th of the body’s oxygen)

People who study the brain are called Neurologists. Neurologists believe that the brain is surrounded by liquid crystals. Show the liquid crystals and how they respond to the heat of your hand.

Not only does the brain control the whole body, but also your emotions, pain, thoughts, and memory. The right side of the brain controls the left side of the body and the left side of the brain controls the right side of the body.

Examine the model of the brain and point out the two cerebral hemispheres and the brain stem that attaches to the spinal chord. The brain works using chemicals and electricity and is sensitive to the food we eat. Some things can hurt our brain like poisons from certain plants or animal bites, pollution in the air and exposure to certain chemicals and metals can cause nutritional imbalances, allergies, brain fog, and chronic fatigue.

We are what we eat! It starts with the soil that determines the nutrients in the plants we eat. Without copper, plant leaves turn yellow. If we get too little copper, we can develop brain fog, thyroid and hormone problems. If we don’t get enough calcium and magnesium, nerves fire improperly, awareness is lessened, and we experience mental fatigue and numbness. It is important where our food comes from, how it is grown, and how clean the environment is.

Use your noodle and make new connections! What animal do you think has the biggest brain? The sperm whale has the biggest brain. (201 lbs.) Our brain weighs only about 3 lbs. A worm has a brain and spinal chord and even a slug is able to learn things!

Activities: Children can make the connection with their finger and light up the energy ball. Examine the chart of the nervous system and realize that nerves reach to all parts of the body and are connected to the brain by the spinal chord. Examine the model of the brain and see how it fits into the skull. Observe the change in the liquid crystals from the heat of their hand. Give them some brain teasers.

Materials: Electric ping pong ball, Skull model, Chart of the nervous system, model of the brain, drawing board and markers, liquid crystals

CLASSROOM BRAIN MODEL

 

 

 

 

 

 

 

 

 

 

 

 

Muscles Move

1. MUSCLES MOVE! Muscle work requires energy! Muscles need oxygen to work. If they don’t get enough oxygen when working, they will produce muscle fatigue from lactic acid and will ache or stop working completely. The energy comes from oxygen and glucose from the carbohydrates you eat. To release energy the glucose must combine with oxygen from red blood cells. Muscles cramp when there is not enough oxygen and lactic acid builds up. Inside muscles ATP is like a battery that stores energy. Muscles work if they have a constant supply of ATP provided by respiration. Aerobic = food + oxygen = ATP. If you exercise intensely and the heart can’t keep up then the anaerobic system takes over and ATP is produced without oxygen and also produces the poison lactic acid. You need protein for healthy muscles. Aerobic exercise increases oxygen in the blood and strengthens the heart. The more you exercise, the more food and oxygen you need. The more you use muscles, the stronger they grow. Without exercise, healthy nourishment and enough oxygen muscles become smaller and weaker. To strengthen muscles you must work against a stronger resistance than used to and increase as muscle training continues. Exercise doesn’t increase the number of muscle cells but increases the size of the existing cells. To develop bigger muscles the individual muscle filaments grow in thickness 24-48 hours later.

Muscles have the only kind of tissue that can contract getting shorter and thicker. Put your thumbs in your ears and you can hear the rumbling sound of your muscles contracting! We have 656 muscles in our body. More than 200 operate when we take a step. They are controlled by the central nervous system through nerve impulses from our brain. If your nervous system weren’t so efficient, you might be socking yourself in the face instead of scratching your nose!

Muscles are voluntary as skeletal muscles or involuntary as organs. Muscles are mostly protein – meat on the bones – flesh. When we eat meat we are eating muscle tissue. There are red and white muscle cells mixed together. Red cells work longer but white cells are stronger. This is why there is white meat and red meat.

Muscles are attached to our bones by tough inelastic tendons. We can see tendons on the back of the hand. You can feel one of the biggest tendons, the achilles at the back of your foot at the heal. Bones are attached to bones by ligaments and joints are oiled by synovial fluid. Cartilage acts as a shock absorber. It is cartilage that grows into bone.

3 kinds of muscle:

1. Striped Skeletal Muscles – Are voluntary muscles. We can control these muscles at will. Most are attached to bone and move us. The muscles can’t push but work in pairs. One relaxes and the other contracts. one muscle gets long and the other contracts to shorten. Our reflex action is involuntary and comes from the spinal chord.

2. Smooth Muscles are responsible for the movements inside of us – our guts and organs. We cannot control the digestive or circulatory system, nor the diaphragm, muscle of the iris in the eye, or the muscle of each hair when we get goose bumps. When we are hungry our stomach muscle contracts and if there is air in the stomach it growls for food!

3. Cardiac Muscle makes up our heart and is our strongest involuntary muscle. We cannot control it and it never stops working till we die. The heart is a pump that feeds oxygen and nutrition to our body.

Muscles Matter – The Benefits of Muscles:

1. Move parts of our body allowing many kinds of activity such as swimming or painting
2. The heart pumps blood through our body to feed it oxygen and nutrition to keep us alive and healthy
3. Protect inside organs
4. Stabalizes the spine of the skeletal system.
5. Shape us – our face and whole body
6. Allow us to breathe, eat, digest food, talk, sing, whistle, see,
7. Allow us to manipulate things
8. Keep us warm with a shiver

The tongue is your most flexible and dangerous muscle. Our smallest muscle is in the ear. The largest in in our rear – the gluteous maximus of our derriere. Our strongest is the jaw masseter muscle we use to bite, chew and talk. The most active muscles are the eye muscles. Takes more muscles and energy to frown than to smile!

In multiple schlerosis a layer of fat is absent from muscles and they can’t transmit nerve messages properly. Muscular dystrophy is when muscles waste away. Muscles can become paralized from brain damage. A strained muscle is one that has been stretched too much.

Be a body scientist and test your reaction time catching a ruler, check your pulse, listen to your heart, listen to your muscles contract, check knee reflex, lung capacity, nail growth, and get outside and exercise!

 

Bones

 

Content: Skeleton Jones and Bones Do you have bones inside of you? Show children the model of the human skeleton and tell them all the bones in the body are called the skeleton. Do animals have bones? Trees? Rocks? Show models of different animals and ask them which ones have bones. Animals that do not have bones are invertebrates. Animals with bones are vertebrates. Show children skulls of different farm animals and let them guess the animal. How do bones help us: They give us our shape, protect parts of our body, help us move, blood is made inside bones, bones hold our teeth, they give us clues to the past’The places where bones meet are called joints. Point out the following joints: Saddle joint (thumb), hinge (knee or elbow) ball and socket joints(hip and shoulder) Children examine a model of the human skeleton. Give a model of an animal to each child and let them tell if they area vertebrate or invertebrate. Let children exercise some the 3 kinds of joints. Children can choose a bone from the bone box, examine it, and help put the skeleton together.

MATERIALS: Model of the human skeleton. Examples of animals that do and do not have bones. The small plastic models of animals are great for this. Examples of bones forming joints.

ACTIVITIES: Children examine model of the human skeleton.  Let children exercise some the 3 kinds of joints. Children can choose a bone from the bone box and help put the skeleton together. Teach the song about skeleton Jones.

 

CLASSROOM SKELETON MODEL

Classroom Skeleton Puzzle

The Circulatory System

If we think of our body as a city then the circulatory system is the subway train that travels through it and feeds everything. The heart is the pump in humans. It beats about 72 times a minute when resting, 38 million times in one year. Newborn = 130/minute , adult = 60-100.  Pumps 1.3 gallons of blood \ minute.

Why does the heart beat faster when we are working or exercising? Pulmonary circulation – to lungs

Coronary circulation – to heart

Systemic circulation – to rest of body Blood travels about 12,000 miles a day

The HEART : 2 ATRIA are the 2 top chambers that receive blood from the body and the lungs.  2 VENTRICALS – 2 bottom chambers – right pumps blood to the lungs – left pumps blood to the body and is the strongest chamber.

There are 4 valves in the heart that keep blood from flowing backwards and it is these that produce the sounds LUB-DUB.  Function: to receive nutrition and deliver it to rest of body and deliver wastes to be discarded by body

Each time the heart beats it is sending another wave of blood through the body. BLOOD VESSELS ARE LIKE TUBES THAT ARE ELASTIC.

Arteries travel from the heart carrying OXYGEN from the lungs to the CAPPILLARIES ( the smallest vessels), They DELIVER THE OXYGEN AND FOOD TO THE CELLS.

Veins travel back to heart carrying wastes= CO2 to the SVC & IVC of the heart.

Coronary arteries supply the heart BLOOD = the fluid of life for growth and health. Carries nourishment from digestion, harmones from glands, Disease fighting substances, Wastes to kidneys.

BLOOD is ALIVE the cells have a life cycle RBC WBC and PLATELETS to clot the blood RBC that carry oxygen.

WBC are germbusters: Phagocytes eat germs. Lymphocytes kill by blasting with antibodies.

PLASMA = 55% of blood, straw colored liquid, contains salts and minerals, antibodies, 90% water

SA node, sinoatrial node, AV node these are bundles of cells that can generate electrical impulses and the special fibers of the heart contract!

Blood TYPES DIFFERENT CHEMICALS – if given wrong type is attacked.

Human blood has the same saltiness as sea water.

If leg goes to sleep not getting blood supply and oxygen.

KIDNEYS filter all of blood

 

How Circulatory system flows:

1. SVC & IVC (Superior Vena Cava and Inferior Vena Cava)

2. right atrium

3. tricuspid valve

4. right ventricle

5. pulmonic valve

6. pulmonary artery

7. lungs to pick up oxygen

8. pulmonary veins (only veins to carry oxygenated blood)

9. left atrium

10. mitral valve

11. left ventricle

12. aortic valve

13. aorta to rest of body

Vessels are tubes that transport blood. A child has vessels that would stretch 60,000 miles long.

Pulse and blood pressure Systole = beats higher # 110-150 Diastole = relaxes lower # 60-80 3 kinds:

1. veins – transport wastes rich blood back to the heart at low pressure there are 3 layers. They are not as strong as arteries, They receive blood from capillaries, the blood is a darker color. There are valves throughout the veins to help with flow of blood.

2. arteries – elastic and very strong. They take oxygen rich blood to all the cells in the body

3. capillaries – are thin and fragile only 1 cell thick, nutrients and oxygen flow to the cells in the body and co2 and wastes are picked up. A single RBC lives about 3 months/ makes 130,000 round trips through the body Veins, arteries, and capillaries measure over 62,000 miles

Blood cells under electron microscope

 

 

The Digestive System

The Digestive System: THE DISSAPPEARING APPLE
The food we eat travels through the alimentary canal, a path that is about 30 feet long from mouth to rectum and includes 2 large glands the liver and the pancreas.

We are food processors! We break down our food by chopping, mashing and mixing it to a nice soup that our body can absorb. Food has minerals like calcium for healthy teeth and bones. The minerals that we need come from non-livings things. Iron is a mineral required by your blood to carry the oxygen you breathe to feed every living cell in your body. Cells must have oxygen to stay alive. The iron that we get from our food originally comes from rock. The core of the earth is iron and many things are made from iron like gates and tools. Zinc and magnesium are other minerals we need.
Plants and animals that we eat contain carbohydrates, proteins, fats, minerals and vitamins like vitamin A to strengthen our eyes, vitamin C to help us heal, and B vitamins to feed our brains! Growing and doing things requires energy and energy comes from fuel! Food, water and oxygen are our fuel. The sun is the fuel for plants to grow and stay alive. In a lifetime we may eat the weight of 6 elephants. Food keeps us strong, builds cells, and allows us to grow and work and play. It helps fix our body if we are hurt or sick and it controls the systems of our body.

What happens to an apple when we eat it? Smelling and seeing food starts the process of producing saliva. The mouth releases 3 cups of saliva a day. In the mouth our teeth and tongue work together to chew food and mix it with saliva. The epiglottis trapdoor to our lungs closes and the tongue pushes the food down into the esophagus (a narrow tube 10 inches long.) It goes into the stomach where it is mashed and mixed with gastric juices and turned into a thick soup. It is in the stomach 2 to 4 hours churning. The stomach has 3 layers of muscles to help churn our food. Mucus protects the stomach from digestive acids. The food is moved into the small intestines (about 22 feet long and the longest part of the canal) where nutrition from the soup is taken into the blood stream by the tiniest blood vessels called capillaries. Then it is taken to a major checkpoint the liver to filter out any harmful substances or wastes. The nutrients are then sent to all parts of our body.

The pancreas makes juices that help the body digest fats and proteins. A juice from the liver called bile helps to absorb fats into the blood stream. The gall bladder is the storage place for the bile. Food not used goes on to the large intestines (about 5 feet long) where the rest of the liquid is absorbed. The large intestine has a tiny tube with a closed end called the appendix that doesn’t do anything. Wastes from our food travels through the colon where the rest of the water is absorbed. The solid waste accumulates in the rectum and is eliminated through the round sphincter muscle called the anus (a circular muscle is a sphincter). A meal takes from 15 hours to 2 days to go through the alimentary canal.

The body can only use one kind of sugar for energy and that is glucose. Plants make there own glucose. If there are bacteria in the food or the stomach is irritated by a germ, the stomach objects and pushes the food out and you stomach ache and you may vomit up the food.

The pancreas produces digestive juices for the small intestines and is like a giant salivary gland. It produces the hormone insulin (glucose) a type of sugar that is fuel for cells, esp. those in the brain. The liver is the largest internal organ and it makes poisons in our food less harmful and produces the green fluid called bile stored in the gall bladder. Kidneys filter and clean the fluid from the blood and sends liquid waste to our bladder and it is eliminated from the body in urination.

To keep the body in good health we must breathe clean air, keep our bodies clean, get enough rest, exercise, and eat foods that have the nutrients our bodies need. The protein we need comes from meat, fish, eggs, beans, and whole grains. Our body rearranges the protein into amino acids that our bodies use for building new cells and tissues. The carbohydrates that we need come from vegetables, fruit, bread, and cereal and the body makes glucose for energy that is stored in muscles and the liver. The fats we eat come from milk, eggs, meat, and oils. They cushion around organs and store energy in the liver and under the skin.

I use the digestive system apron with students and may have them eat an apple or pretend to eat an apple. The apron is available through one of the suppliers listed on the resource page. I may discuss animals that have 2 stomachs or a crop to store food. We may discuss herbivores, carnivores, and omnivores and those that have beaks and the differences in teeth depending on their diet. This is a good time to follow up on nutrition and the food pyramid and for very young children I have samples of food for them to identify and learn how it is good for the body.

The importance of teeth and chewing your food.

Chewing is a very important part of healthy digestion. Chew your food well. What you get in return is better health. Chew your food completely to be swallowed with ease. Digestion begins with chewing your food. Chewing breaks down food molecules to smaller particles. Increases the surface area, reduces esophageal stress and exposes food to saliva for a longer time. Saliva helps lubricate the food making it easier for foods to pass through the esophagus. The enzymes in saliva contribute to the chemical process of digestion. Carbohydrate digestion begins with saliva. The first stage of fat digestion also occurs in the mouth. Incomplete digestion can lead to bacterial growth. When food is not well chewed and food fragments are too big to be broken down, incomplete digestion occurs. Nutrients do not get extracted from the food and it becomes fodder for bacteria in the colon, which can lead to bacterial overgrowth, flatulence, and symptoms of indigestion. Chewing relaxes the lower stomach muscle. Chewing is directly connected with the movement of food through your digestive tract, and with the movement of food from your stomach to your small intestine. At the lower end of your stomach, there is a muscle called the pylorus. This muscle must relax in order for food to leave your stomach and pass into your small intestine. Sufficient saliva from optimal chewing helps relax the pylorus, and helps your food move through your digestive tract in a healthy fashion. Chewing triggers the rest of the digestive process. The process of chewing activates messages to the rest of the gastrointestinal system to begin the entire digestive process. Chewing activates taste receptors in the mouth and prompts the nervous system to relay information to the gastric system to optimize the process of digestion. Stimulation of the taste receptors can signal the stomach lining to produce hydrochloric acid that helps in the breakdown of protein. Chewing also signals the pancreas to prepare to secrete enzymes and bicarbonate into the lumen of the small intestines.

Our Amazing Body

Our Amazing Body!

The CELL is the basic unit of LIFE. There are billions of cells in your body. Each cell has special work to do for your whole body. Like cells combine into tissues like muscle, nerve, bone. Tissues combine into organs like your heart and lungs. Organs combine into systems like your circulatory, digestive, or skeletal system. There are over 50 trillion cells in the body / more cells than stars in our galaxy. Many cells are so small that 100,000 can fit on a pinhead. Cells work like people in a big city: some handle food, some send messages, some keep things clean. Each cell is protected by a cell membrane that surrounds it. There are strings of genes in cells that contain information from your parents that determine much the way you are. Cells are always dieing and being replaced. Skin completely replaces itself about once a month.

Our body is 70% water and has enough carbon to make the lead for 9000 pencils.

Our greatest gifts are our brain and our hands.

We grow 25 feet of HAIR in a lifetime.

The most sensitive part of the body is the tongue. The most flexible muscle in our body is the tongue! It can also be the most dangerous! The least sensitive part of the body is the middle of the back.

Animals can run faster than we can but we have more endurance and can outrun over long distances

The skull contains the holes for receiving food, water, and oxygen.

The lungs almost fill the thorax above the diaphragm. Most of the body’s hormones are produced in the abdomen below the diaphragm.

Organs of the systems of our body:

SKELETAL SYSTEM: BONES AND LIGAMENTS

NERVOUS SYSTEM: BRAIN, SPINAL CHORD, AND NERVES

DIGESTIVE SYSTEM: TEETH, TONGUE, ESOPHAGUS, STOMACH,

SMALL INTESTINES, LARGE INTESTINES, LIVER, PANCREAS.

CIRCULATORY SYSTEM: HEART, ARTERIES, CAPILLARIES, AND

VEINS

MUSCULAR SYSTEM: MUSCLES, TENDONS, AND CARTILAGE