Nervous System MS-LS1-3: Use argument supported by evidence for how the body is a system of interacting subsystems composed of group of cells. MS-LS1-8: Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories.

I. Function (job) of the Nervous System A. The main role of the nervous system is to relay electrical signals through the body. 1.The nervous system directs behavior and movement, and along with the endocrine system, controls physiological processes such as digestion, circulation, etc. 2. Responds to stimulus

B. Two Systems within a System 1. Peripheral Nervous System (PNS)– communication pathways (nerves) that connect all areas of body to the Central Nervous System. 2. Central Nervous System (CNS)- brain, and spinal cord: processes all incoming and outgoing messages.

Question 1.What is the main job of the nervous system? 2.What are some of the activities the nervous system controls in our bodies? 3.Explain the difference between the Central Nervous System and the Peripheral Nervous System. a. b.

Question 1.What is the main job of the nervous system? relay electrical signals through the body and to process all incoming and outgoing messages. 2. What are some of the activities the nervous system controls in our bodies? Movement, digestion, circulation, response to Stimulus/messages. 3. Explain the difference between the Central Nervous System and the Peripheral Nervous System. a. Peripheral Nervous System are the communication pathways (nerves) that connect all areas of body to the CNS. b. Central Nervous System [CNS]- brain, and spinal cord: processes all incoming and outgoing messages.

II. Organs (Parts) that Support the Nervous System A.Major Parts of Peripheral Nervous System (PNS) 1.Neuron- specialized cells that transfer messages throughout the body in the form of fast – moving electrical energy. a. Dendrites – branched extensions at the end of neurons to receive info. b. Axon- fibers that transmit information. c. Synapse – space between the receptors and the axon.

2. Receptors – specialized sensory dendrites detect changes inside and outside the body. ex. Receptors in eye can detect light (electromagnetic input) 3. Motor Neurons- neurons that send impulses from the brain and spinal cord to other body systems. ex. Receptors can detect movement or touch (mechanical signals) 4. Nerves- axons bundled together with blood vessels and connective tissue sends and receives info *Found throughout the body

B. Major Organs of Central Nervous System (CNS) 1. Brain has hundreds of different jobs. a. Controls body system processes. –Involuntary processes= process of the body we don’t have to think about for them to function. Ex. Heart beating and blood moving in the circulatory system, food moving through the digestive system. –Voluntary processes= process of the body that we choose or think about for them to function. Ex. Muscles and bones working together to walk, or raise your hand. (locomotion)

b. Responds to Stimuli - Reflex – responses to stimuli that the brain controls automatically ex. Pulling hand away from hot stove, ducking when a ball flies at face. - Reaction– responses to stimuli that you have control over or choose to do.(learned) ex. Putting your hand up to catch the ball instead of ducking, or raising your hand when teacher asks a question

c. 3 Main Parts of Brain: Cerebrum – Where we think, and most memories are stored. - Two hemispheres (left controls the right side of the body/ right controls the left side of the body) Cerebellum – Receives sensory impulses from skeletal muscles and joints to keep track of your body’s position. -Helps keep balance. Brain Stem – Connects to the spinal cord - Controls blood pressure, heart rate, and involuntary breathing

2. Spinal Cord a.Contains neurons and axons that pass impulses to and from the brain. b.Surrounded by vertebrae (protective bones) c.Nerve fibers enable brain to communicate with peripheral nervous system.

3. Sensory Organs a. eyes b. ears c. nose d. mouth e. skin

Questions 1. Given the parts of the nervous system tell what each is responsible for. a. neuron- b. dendrites – c. axon- d. synapse – e. receptors – f. motor neurons- g. nerves- h. brain- i. spinal cord – j. sensory organs -

Questions 1. Given the parts of the nervous system tell what job each is responsible for. a. neuron- transfer messages b. dendrites – receive info c. axon- transmit info d. synapse – space between the receptors and the axon e. receptors – detect changes inside and outside the body f. motor neurons- neurons that send impulses from the brain and spinal cord to other body systems g. nerves- send and receive info h. brain- think, control movement, store info and memories i. spinal cord – pass impulses to and from the brain j. sensory organs – respond to stimulus like light (electromagnetic), sound, touch (mechanical), smell, hormones (chemical) etc.

III. Information Processing A. The brain’s main role is to process all information (incoming and outgoing messages) for immediate response or storage of memories. B. Information is received by sense receptors. C. Signals or inputs that are received by the brain are processed and result in immediate behaviors or memories.

Three Main Type of Sensory Inputs 1.Electromagnetic ~ response to light. –Sensory organ: Eyes a.The Eye: converts electromagnetic energy that is light into nerve impulses. These signals then travel along nerve cells to the brain, for immediate use. Ex – Walking into sunlight from a dark room and squinting.

Visual Perception: Sensory intake of visual stimuli must be processed by brain into organized structures (i.e., perception) the eye by itself cannot organize visual input into shapes that correspond to objects…this is the brain’s job. Ex. The first time you see something you don’t know what it is, your brain has to categorize it (like first time seeing a labradoodle, or capybara).

Three Main Types of Sensory Inputs (cont.) 2. Mechanical ~ response to movement or touch. Sensory Organs: Ears and Skin a. Ears Sound is the perception of moving-air waves b. Skin the body’s largest sensory organ. Millions of skin receptors mix and match to produce specific perception: -Ex. Temperature distinct spots on skin that register only hot or cold - Ex. Pain warns us of impending danger; crucial to survival

OUCH ! Pull hand back! I hear and see dog growling..don’t pet!

Kinesthetic Sense (balance) Provides information about position of joints, muscles, limbs. Gives us control over body movements –Ex: When you close your eyes, you can still touch your nose –Ex. Leaning when you ride a bike around a corner.

3. Chemical ~ response to chemicals in the body such as hormones (adrenaline) and outside stimuli (out of the body) odors, pheromones -Sensory organ: nose and mouth a. Response to chemicals in the body Ex. Hormones – adrenalin (fight or flight, super strength) b. Response to chemicals out of the body Ex. Smell –Olfaction: sense of smell / use your nose (smell that reminds you of your grandma) –Receptors send the neural signals to the brain, passing the thalamus (memory) and the limbic system (emotions) along the way –This is why odors often trigger emotional memories Ex. Taste –Gustation: sense of taste –Taste buds: bumps on the tongue surface, back of throat, and inside the cheeks –Detect molecules of substances that have dissolved in saliva –Four types: sweet, sour, salty, and bitter

Three Main Types of Input (cont.) 3. Chemical ~ response to chemicals in the body such as hormones (adrenaline) and outside stimuli (out of the body) odors, pheromones Sensory Organs: Nose and Mouth a.Response to chemicals in the body -Ex. Hormones – adrenalin (fight or flight, super strength) b.Response to chemicals out of the body - Ex. Pheromones- chemicals secreted by our bodies that trigger a response

Ex. Smell Olfaction: Sense of smell- use your nose (smells that reminds you of your grandma) Receptors send the neural signals to the brain, passing the thalamus (memory) and the limbic system (emotions) along the way This is why odors often trigger emotional memories

Ex. Taste Gustation: Sense of taste Taste Buds: Bumps on the tongue surface, back of throat, and inside the cheeks Detect molecules of substances that have dissolved in saliva. Four types: Sweet, sour, salty, and bitter.

Question What is the main job of the brain? What are the 3 main types of inputs and what do they respond to?

Question What is the main job of the brain? The brain’s main role is to process all information (ingoing and outgoing messages) for immediate response or storage of memories. What are the 3 main types of inputs and what do they respond to? 1.Electromagnetic ~ response to light. 2.Mechanical ~ response to movement or touch. 3.Chemical ~ response to chemicals in the body and outside stimuli (out of the body)