Nervous System

Lesson 7 Vocab neurons – nerve cells, which make up your nervous system cerebrum – the largest part of the brain; where most of your thinking takes place cerebellum – the part of the brain that makes your muscles work together; controls most movements that you do without thinking hemispheres – two halves of a sphere, or ball-shaped object, such as the brain

brain – the major organ in the nervous system spinal cord – an organ that carries messages to and from the brain nerve – is a bundle of cells that conducts messages from one part of the body to another reflex – an automatic response to stimuli

Nervous System 1. The nervous system controls all the systems in your body 2. What do your nerve cells and nerves do? –a. Cells of your nervous system are called nerve cells, or neurons i. Neurons have long branches that come out both ends ii. They are long and thin iii. Bundles of neurons make up nerves

–b. nerves receive and send messages –c. some carry messages to the brain to let it know what is happening in and around your body – sensory nerves –d. others carry messages from the brain to muscles, telling muscles what to do – motor nerves

How Does your Brain Work –a. The brain is the “control center” of the body –b. Always receiving messages and sorts them out looking for meaning, then tells the body what to do

c. 3 main parts c. 3 main parts i. Cerebrum – largest part, where most thinking takes place, solves problems, forms emotions (feelings), makes decisions, and controls how you learn, receives and answers messages from senses –1. divided into 2 halves called hemispheres, each side responsible for different tasks –2. 2 halves connected by the corpus callosum –3. right side deals with imagination and the arts –4. left side deals with words and facts, math –5. both are always working together

1086 A concussion is a brain injury which occurs when the head takes a sudden blow, banging the brain against the side of the skull. Concussions range from mild (no loss of consciousness) to severe (loss of consciousness). Patients typically suffer headaches, nausea and dizziness in the short run and some develop enduring headaches, dizziness and confusion for months. Athletes at Central Dauphin East have to take an Impact test to give a baseline for how their brains function prior to a concussion. If they hit their head playing sports and can’t pass the same test, they have to get treatment for concussion.

ii. Cerebellum – the part of the brain that makes muscles work together, helps move and keep balance, cerebellum directs most movement without you thinking about it iii. Brain stem – lowest part of the brain, messages moving between brain and the rest of the body pass through the brain stem –1. medulla oblongata takes care of critical life functions – breathing, heartbeat, swallowing, blood vessels, controls inner organs

4. What is the job of your spinal cord? –a. Starts at the base of the brain, main path for messages entering and leaving the brain –b. Surround and protects spinal cord connecting nerves to brain –c. Sudden actions that are done without thinking are reflexes

Peripheral Nervous System Nerves connect all parts of the body to the Central Nervous System (the brain and spinal cord) Nerves serve as a means of communication between the Central Nervous System and the body

Common Problems of the Nervous System Meningitis – an infection of the protective coverings of the brain and spinal cord caused by bacteria or a virus… bacteria is treated by antibiotics and there is a vaccine. The viral form is most common and milder… the West Nile Virus is one! No vaccine, just avoid mosquito bites if you can! Rabies – viral infection of the brain… passed by the bite of an infected animal – avoid animals acting strangely and get immediate medical attention if bitten

Concussion – an injury to the brain caused by a blow to the head – may cause loss of memory or consciousness… can be prevented by wearing protective headgear Stroke – the death of brain tissue due to a lack of blood to the brain – requires immediate medical attention and hospitalization Paralysis – partial or total loss of the ability to use muscles usually caused by damage to the brain or spinal cord – may be permanent

Epilepsy – a disorder of the nerves and brain that is characterized by uncontrollable muscle activity (seizures)… treated with medication Cerebral Palsy – poor muscle control caused by damage to the brain, often at birth … no cure or prevention but may be helped by physical therapy

Review lesson 7 Review – Lesson 7 1. What does your nervous system do? 2. How are sensory and motor nerves different? 3. What are the jobs of the cerebrum? 4. How are the hemispheres of your brain able to exchange nerve messages?