Transcript spinal cord
Pgs. 288-291 in Text The human body has many body systems, including … All of these body systems are very important! • Yes, Professor. But which body system controls ALL of them? • That’s Right! • The Nervous System This Lesson Will Cover: 1. 2. 3. 4. 5. 6. 7. 8. 9. Main Parts of the Nervous System How the Nervous System is Protected Jobs of the Nervous System Neurons (Nerve Cells) 3 Types of Neurons The Brain The Spinal Cord Nervous System Problems Proper Care of the Nervous System OK, Dexter ! PART 1: Main Parts of the Nervous System Probably! WHAT ARE THE MAIN PARTS OF THE NERVOUS SYSTEM? 1. The BRAIN 2. The SPINAL CORD 3. All the NERVES going to and from the brain and spinal cord WHAT ARE THE MAIN PARTS OF THE NERVOUS SYSTEM? 1. The Brain and Spinal Cord make up the CENTRAL NERVOUS SYSTEM 2. All the Nerves going to and from the brain and spinal cord make up the PERIPHERAL NERVOUS SYSTEM WHICH PART IS MOST IMPORTANT ? Let’s explore how the body protects each part of the Nervous System … PART 2: How the Nervous System is Protected • It must be protected and kept safe inside your body Nervous System tissue is very soft and delicate. How does your body PROTECT all these important and delicate parts of the Nervous System? There are five ways 1. Bones ! • 22 skull bones protect the brain Cranium = 8 bones Face = 14 bones • 31 vertebrae protect the spinal cord 8 cervical segments 12 thoracic segments 5 lumbar segments 5 sacral segments 1 coccygeal segment 2. CEREBROSPINAL FLUID ! • Protects the brain (under the skull) • Protects the spinal cord (inside the vertebrae) • Average adult has about 125-150 ml of cerebrospinal fluid 3. MENINGES ! • The Meninges are special membranes which protect the brain and spinal cord • Three layers: – the dura mater, – the arachnoid mater, – the pia mater. 4. Cartilage! • There are discs of cartilage between the vertebrae • They Protect the spinal cord between each of the vertebra • Singular = vertebra • Plural = vertebrae 5. OTHER WAYS ! • Major nerves are often buried deeper in the body near bones and beneath layers of muscle and fat for protection I should have sat beneath a FIG tree … Hey Isaac: Let’s explore the jobs or functions of the Nervous System! PART 3: Jobs (Functions) of the Nervous System • The BRAIN is the control center of your body! • The BRAIN allows you to voluntarily control speech, vision, hearing, emotions, movement, memories, and thinking. The Jobs of the BRAIN • The BRAIN also regulates breathing, heartbeat, and digestion involuntarily The Jobs of the SPINAL CORD • The SPINAL CORD is the main pathway for all signals to and from the brain • The SPINAL CORD also controls certain reflexes • If the SPINAL CORD is damaged, signals to and from the brain are blocked! • The NERVES send all the messages of sight, smell, taste, hearing, and touch to the brain so you know what’s going on around you • The NERVES also take signals from your brain to all your muscles, glands, and organs so your body can function The Jobs of the NERVES That’s correct, Albert. Let’s see what special cells make up your Nervous System PART 4: Neurons (Nerve Cells) Hey, Anton! You’re the father of microbiology and pioneer of the microscope! What are you looking at? Just like walls are made of bricks … Your body is made of cells Your Nervous System is made of NEURONS (nerve cells) 1. The main parts of the Neuron: = Dendrites = Nucleus Cell Body = 3. 2. What about a more detailed Neuron? 4. = Axon Let’s label a more detailed Neuron: How Do Neurons Work? SIGNALS PASS: 1. 2. 3. 4. 5. from the Dentrites, through the Cell Body, down the Axon, through the Axon Terminals, to another Neuron • The thicker the Myelin Sheath, the faster the neuron can work • Some neurons can carry signals as fast as 200 miles per hour! How fast does this happen? Pronounced “SIN NAPS” Neurons carry signals all over your body, all the time • The signals are both electrical and chemical in nature • What do you think Stimulant drugs do? • How about Depressant Drugs? • Hallucinogens? • Pain Relievers? Different drugs affect the way signals go from neuron to neuron across the synapse Neurons are cool … Any last words, Anton? PART 5: Three Types of Neurons (Nerve Cells) 1) Sensory 2) Connecting (Interneurons) (Association) 3) Motor Spinal Cord 1) Sensory Neurons: • Take signals to the brain and spinal cord from the skin, eyes, ears, nose, mouth, and other organs 2) Connecting: (Interneurons) (Association) • Neurons in the brain and spinal cord 3) Motor Neurons: • Take signals from the brain and spinal cord to muscles, glands, and organs • There are one way tracks going to the station • There are tracks in the station • There are one way tracks going from the station Your Nervous System’s neurons are kind of set up like a Train Station: That “Train Station” analogy was pretty good! • Thanks, Thomas. Did you invent the train? Nope … I invented almost everything else, though! AN EXAMPLE: 1. 2. 3. 4. 5. Stimulus: Pin jabs your skin Sensory neuron signal to brain and spinal cord Association neurons interpret the signal (pain) Motor neuron signal to muscle Muscle moves! ANOTHER EXAMPLE: I’m not a “Train” guy. I’m more of a “Chemistry” guy, myself. Sorry … PART 6: The Brain • OK, Madame. • We will avoid corny brain jokes. • Has about 100 billion neurons! • Weighs about three pounds (1300-1400 grams) • The average human brain is 140 mm wide, 167 mm long, and 93 mm high. A Few Brain Facts: A Few Brain Facts: • You will become unconscious within 8-10 seconds after loss of blood supply to the brain • The brain feels like a ripe avocado and looks pink because of the blood flowing through it Let’s examine the three main areas of the brain and the jobs of each part: • Breathing and Heartbeat • Swallowing and Digestion • Blood Pressure • Coughing, Gagging, Sneezing reflexes • Alertness, Consciousness 1. Brain Stem: • Balance • Posture • Muscle Tone • Coordination of muscle movements 2. Cerebellum: 3. Cerebrum: • Five Senses • Thoughts and Reasoning • Emotions • Memory • Muscle Movements What do you think happens if neurons get damaged here? Or here? Or here? Lobes of the brain: Your brain's hemispheres are divided into four lobes. 1. Frontal lobes- control thinking, planning, organizing, problem solving, short-term memory and movement. (Voluntary movements, personality, speech) 2. Parietal lobes- interpret sensory information, such as taste, temperature and touch, body position, heat, cold, pain, touch. 3. Occipital lobes- process images from your eyes and link that information with images stored in memory. (Vision) 4. Temporal lobes- process information from your senses of hearing, smell, taste and sound. They also play a role in memory storage. This explains why strokes affect different people in different ways Which area of the brain is damaged by the stroke will determine what problems the person has after the stroke Can You Label The Brain and Spinal Cord? W= Brain Stem X= Spinal Cord Y= Cerebellum Z= Cerebrum Your brain has two sides or hemispheres • We use both sides all the time. • Both sides “communicate” with each other • Each side has specialties or jobs it like to do Left & Right Side Motor Control • The left side of your brain controls the right side of your body • The right side of your brain controls the left side of your body. • Do you see why? But … Check out the specialty of each side of our brain Again: We use both sides of our brains all the time: Right Brain vs. Left Brain Leo! You used both sides of your brain quite well … PART 7: The Spinal Cord • All signals to and from the brain go through the Spinal Cord • It is very delicate • It is protected by the vertebrae and discs of cartilage Nerves branch off the Spinal Cord to and from various body organs Spinal Reflex 1. Nerve is hit near knee (sensory) 3. Muscles contract (motor) 2. Spinal cord reacts (association) PART 8: Nervous System Problems There are hundreds of problems which can affect the nervous system Some are more severe than others Doesn’t the famous scientist, Stephen Hawking, have a nervous system problem? Correct. He has a motor neuron disease similar to ALS: Amyotrophic Lateral Sclerosis • Yet his mind works great! • In fact, he is a genius! I Agree. His condition has left him almost completely paralyzed Some common nervous system problems include: 1. 2. 3. 4. 5. 6. 7. Stroke Spinal Cord Injuries Concussion Epilepsy Multiple Sclerosis Alzheimer’s Meningitis • Stroke is the 4th leading cause of death in the US • It is a lack of blood flow to the brain • A blood vessel in the brain breaks or is blocked LEADING CAUSES OF DEATH: 1) Heart Disease approx 600,000 deaths 2) Cancer 575,000 3) Chronic Lower Respiratory Diseases (Lungs) 138,000 4) Stroke 130,000 5) Accidents 118,000 6) Alzheimer's Disease 83,000 7) Diabetes 69,000 8) Kidney Disease 51,000 9) Influenza and Pneumonia 50,000 10) Suicide 38,000 Stroke is the 4th Leading Cause of Death in the US • It is dangerous if the blood supply to any part of the brain is cut off • The brain only weighs 3 pounds (about 1%-3% of your body weight) • Yet 15%-20% of the blood flow from heart goes to the brain! • Strokes can be minor or major in severity • Strokes can cause permanent damage to almost any part of the brain and lead to death! • Learn how to act F.A.S.T. if someone has a stroke! • Damage to the spinal cord is very serious • Car accidents, falls, and other injuries often are the cause • See what can happen if the spinal cord is damaged! • The damage is often permanent • An injury to the brain caused by a blow to the head or by violent jarring or shaking • Often involves loss of consciousness, which may be momentary or may last for several hours • Concussions may cause bruising to the brain • They can be very serious! • Concussions are often caused by sports injuries and car accidents • A disease involving seizures • An area of the brain sends irregular signals to the muscles, causing involuntary muscle contractions • Less severe seizures are called Petit Mal Seizures • More severe seizures are called Grand Mal Seizures • People with epilepsy often take medications to make seizures less severe and happen less often • The neuron’s coating (Myelin Sheath) is damaged or destroyed Multiple Sclerosis: When the nerve coating is destroyed, it is similar to destroying the coating of an electrical wire Can you think of what problems this might present? MS can result in a variety of problems almost anywhere in the body Causes An age-related and irreversible brain disorder that occurs gradually Results in memory loss, behavior and personality changes, and a decline in thinking abilities. Causes As many as 5.3 million Americans are living with Alzheimer’s disease. Every 70 seconds, someone develops Alzheimer’s. Causes The direct and indirect costs of Alzheimer's and other dementias to Medicare, Medicaid and businesses amount to more than $148 billion each year Named for German physician Alois Alzheimer, who first described it in 1906. Causes Alzheimer’s Disease is the SEVENTH Leading Cause of Death in the US !! Check out the following chart Alzheimer’s Disease Causes is the seventh leading cause of death in the US: Leading Causes of Death in the US – 1) Heart Disease 631,636 (26% of all deaths) 2) Cancer 559,888 (23.1%) 3) Stroke 137,119 (5.7%) 4) Chronic Lower Respiratory Diseases (Lungs) 124,583 (5.1%) 5) Accidents 121,599 (5%) 6) Diabetes 72,449 (3%) 7) Alzheimer's Disease 72,432 (3%) 8) Influenza Virus and Pneumonia 56,326 (2.3%) 9) Kidney Disease 45,344 (1.9%) 10) Septicemia (infection of the blood) 34,234 (1.4%) • The meninges (membranes) surrounding the brain or spinal cord get infected • The infection can be bacterial or viral • Can affect brain or spinal cord • It is potentially very serious! PART 9: Proper Care of the Nervous System “What about me ?” “I am the coolest, most famous scientist of all” “Besides … I look like a young Abe Lincoln!” OK, Bill. You can be in the last segment! Science Rules !!! 1. 2. 3. 4. Get enough sleep and rest Eat well-balanced meals Avoid alcohol and other drugs Wear proper safety equipment while playing sports 5. Wear a safety belt / helmet 6. Keep both mentally and physically active How to properly care for the nervous system: 1. Get enough sleep and rest: Your nervous system needs periods of rest to work properly 8 hours of sleep per night is average You may need more! Go to bed earlier! Eat a variety of foods, including fruits and vegetables For your nerves to work properly, your body needs the proper nutrients Drink lots of water, too! 2. Eat well-balanced meals: REMEMBER: Food is fuel for your brain Drugs and alcohol can cause permanent damage to your brain and nervous system In addition, drugs and alcohol can lead to accidents and injuries 3. Avoid alcohol and other drugs: 4. Wear proper safety equipment while playing sports: Competitive sports and physical activities are great! But be careful!! Wear proper safety equipment. In a car, buckle your safety belt! On bikes and cycles, wear a helmet! Remember Newton’s Laws of Motion! 5. Wear a safety belt / helmet: 6. Keep both mentally and physically active: Physical activity gets blood and oxygen flowing to the brain Mental activity keeps your mind stimulated and helps keep you sharp and alert THANKS FOR PAYING ATTENTION! • We hope you learned a few things this week. • Can we get a scientists group photo? Wait! We can’t forget Jane! Why wasn’t Jane in the slide show? She was monkey-ing around That was a really bad joke! I can’t take any more bad scientist jokes! Group Photo !!! Why was I not invited?