Unit 3 Workings of Mind & Body Nervous Systems

Structure of Nervous System  Central Nervous System – part of nervous system that consists of the the brain and spinal cord  What is it’s job : Roadway between brain and the rest of the body  Peripheral Nervous System – made up of nerve cells that send messages between the central nervous system and other parts of the body  Back roads of central nervous system  Neurons – nerve cells that run through our entire body and communicate with each other (part of peripheral)  Send & receive messages from other parts of the body, such as muscles and glands.  Messages relate to events like a pinch or a memory  Neurons are individual cells, nerves are a large collection of nerve fibers

What makes up a Neuron?  Cell body – produces energy that fuels the neuron’s activity  Dendrites – branch out from the cell body. They receive information from other neurons and pass message through cell body.  Many  Axon – transmits information away from the cell body  Only one  Myelin – fatty substance that protects the axon  Synapse – junction between axon terminals of one neuron & the dendrites of another. Messages only go forward

Types of Neurons  Neurons are classified by the direction in which they carry information  Sensory – send information from the sensory receptors (eyes, ears, nose, mouth) TO the central nervous system  Motor – Take information AWAY from the central nervous system and carry it TO muscles and glands.  Interneurons – Carry information between sensory neurons and motor neurons  Most are located in the central nervous system

What is a Neurotransmitter?  Neurotransmitters are chemicals that are stored in sacs in the axon.  How does it work? A neuron fires (sends message) by releasing neurotransmitters. Each message is converted into a electrical impulse that travels.  The message is then forwarded to the next neuron by other neurotransmitters, until it reaches its destination.  What happens if neurotransmitters are misfiring?  Can cause some diseases or psychological disorders  For example, deficiency in neurotransmitter dopamine plays a role in Parkinson's disease. (not enough dopamine)  Hallucinations and hand shaking  Too much dopamine, may contribute to Schizophrenia  Hallucinations and illusions

Neurons…the video  moE moE

Nervous System Break Down SystemFunctionDetails Central Nervous System C.N.S. Made up of the brain and spinal cord. Transmits messages between the brain and the muscles & glands in the body. Brain depends on spinal cord to send the message Peripheral Nervous SystemLies outside the C.N.S. & Is responsible for transmitting messages between the C.N.S. & rest of body Split into the Autonomic & Somatic Nervous System Autonomic Nervous System Regulates body’s vital functions that don’t require thought: heartbeat, breathing etc. Helps your body prepare for stressful situations like fight or flight. Somatic Nervous SystemTransmits sensory messages to the C.N.S. Carry messages from the voluntary muscles & sense organs Activated by touch, pain, changes in temperature etc.

Central Nervous SystemPeripheral Nervous System

Autonomic Nervous SystemSomatic Nervous System

Fight or Flight Response Video  How do our bodies react to fear?  What is adrenaline?  Have you ever heard of an adrenaline rush? What is it?  Can adrenaline make you do extra ordinary things?

Reaction Lab

Exit Ticket  Page 71 of text book  Answer numbers 1-4