The Nervous System Defined: a complex system that tells our body what to do What do you think the nervous system does to coordinate the different systems? Learning Objective (L.O.): I will identify the functions and parts of the nervous system.

Five Jobs Maintains our consciousness: helps us stay alert and aware of everything happening all around us and helps us to respond to our surroundings. Coordinates what we sense or feel by using our 5 senses sight smell taste touch hearing Reaction to our senses: tells us what to do when sense something; acts as a control center and directs our bodies in the correct way Learning: helps us to understand what we are feeling or sensing and it tells us how to direct the information. Memory: guides us in remembering tasks already learned, as well as past experiences and feelings.

MEMORY: 3 TYPES Sensory Memory: acts as a gatekeeper to our brain; holds new information long enough to decide whether to move it to short-term memory and act on it or discard it. e.g. holds sounds you hear long enough for you to decide if you are hearing speech or music, lasts 2-3 seconds, we are not aware of it. Short-Term Memory: Sometimes called the working memory. Stores everything we do but it stays in our memory for a short time. Long-Term Memory: Memory we use to recall information - both important and unimportant- for very long periods of time e.g. can be for a skill, such as riding a skateboard, or facts, such as your mom's birthday, or what someone looks like. The more you use something in short-term memory, the more likely it is to become long-term memory.

Fact: most people cannot store more than 10 numbers in a series in their long-term memory. This is why combination locks and phone numbers are less than 10 numbers.

PARTS OF THE NERVOUS SYSTEM BRAIN: head quarters of our nervous system gets messages and sends messages through your nerves; controls everything that you do! CEREBRUM: controls thought, memory and learning MEDULLA: controls involuntary actions (breathing, heart beating, digestion) CEREBELLUM: coordinates movement and maintains balance. BRAIN STEM: base of the brain connecting the spinal Cord with the brain. HIPPOCAMPUS: concerned with memory; works with your cerebrum PITUITARY GLAND: controls growth

FACTS ABOUT THE BRAIN Controls everything you do - breathing, eating, reading, etc. Humans have the largest brain for their body size in the animal world. The right and left side of the brain are mirror images of each other. They are connected by a thin cord. The hypothalamus is the brain's built-in thermometer and controls our body temperature degrees. It tells our bodies when to sweat, and controls eating, sleeping, and physical signs of emotion (racing heartbeat, sweaty palms, etc.) Each side of the brain controls the opposite side of the body. Most people have a more powerful (dominant) left brain. Right handed. Right brain: controls creativity & imagination Your brain cannot feel pain.

BRAIN GROWTH Babies: have full set of brain cells, approx. 100 billion. Brain cells are called neurons, they aren't well connected. A baby's skull is partially open so brain has room to expand. By age 5: brain is almost completely formed. It doesn't get any more brain cells, but it does get more connections between cells. Up to 8: humans can recover from severe brain injury. Healthy nerve cells take over for the lost or damaged one. At age 12: brain stops growing and the skull fuses into a solid case. Stops growing but keeps learning, making new connections between cells throughout life. Early 20's: brain begins to shrink, each day an adult loses thousands of brain cells. Late 50's and 60s: people lose brain cells at a faster rate. Their brains make new connections at a slower rate. LO: I will identify the stages of brain development.

0 Circles = neurons line = connection

Does your brain sleep? NO! Stages of Sleep 1. Time for bed: your brain releases a "sleepy" chemical. 2. Drifting off: your heart rate and breathing lowers, body temperature drops, muscles relax, tuned out 3. Light sleep: you shift around a lot, noise, smell, touch will wake you easily 4. Deep sleep: blood pressure drops, can't sense temperature 5. Deepest sleep: sleepwalkers and talkers, almost nothing will wake you, lasts only a few minutes 6. Repeat: stages 3, 2, and a similar phase to stage 1 called REM (rapid eye movement) 4-5 times a night REM: when you dream, everyone dreams! LO: I will identify the stages of sleep.

SPINAL CORD: A long cord made of nerve cells. It runs from your brain all the way down your back inside the bones of your spine. Most nerve messages pass through your spinal cord on the way to and from your brain.

NERVES : act as the "trigger" or driver of brain instructions; known as the "phone lines" of the body. : work in groups to take the messages from the brain to different parts of the body. 12 pairs of cranial nerves coming from your head 31 pairs of spinal nerves coming from your spine