Welcome it is a great day to learn about the Brain

What does the Brain do? Stand up Walk around every person you pass tell them a different function the brain performs Do this until you are told to stop

Why do we study the Brain? Back at your tables report back what you learned about what the brain does did you learn anything new?

We are going to start small and go big

Just as I Thought, low self esteem Why can t my skull bumps be prettier? Phrenology Franz Gall-(1758-1828) Pseudoscience-based on false assumptions. Why so popular? Individual ability to change and develop Improved treatment of the insane (organic) Encouraged people to think scientifically

Module 7: Neural and Hormonal Systems Neurons: The Building Blocks of the Nervous System

What are the primary parts of a typical neuron? Nervous system Neurons Dendrites Soma Axon Terminal branches of Axon Myelin Sheath

Nervous System The electrochemical communication system of the body Sends messages from the brain to the body for movement Brings information to the brain from the senses

Neuron The basic building block of the nervous system -- a nerve cell Neurons perform three basic tasks Receive information Carry the information Pass the information on to the next neuron

Neurons Neurons fire -- send an impulse down their length -- or they don t fire Neurons come in a variety of shapes, sizes, etc.

Parts of the Neuron

Parts of the Neuron - Dendrites

Parts of the Neuron - Soma

Parts of the Neuron - Axon

Parts of the Neuron Myelin Sheath

Parts of the Neuron - Terminals

Time to Move Locate the person furthest from you Go to that person Introduce yourself

Pick an A and D A = Axon D= Dendrite With your partner explain the relationship between neurons

Neuron

Neural Communication: The Neural Impulse

Action Potential A brief electrical charge that travels down the axon of the neuron. A neural impulse Considered an on condition of the neuron

Refractory Period The recharging phase when a neuron, after firing, cannot generate another action potential Once the refractory period is complete the neuron can fire again

Resting Potential The state of a neuron when it is at rest and capable of generating an action potential The neuron is set and ready to fire

Steps of Action Potential Dendrites receive neurotransmitter from another neuron across the synapse. Reached its threshold- then fires based on the all-or-none response. Opens up a portal in axon, and lets in positive ions (Sodium) which mix with negative ions (Potassium) that is already inside the axon (thus Neurons at rest have a slightly negative charge). The mixing of + and ions causes an electrical charge that opens up the next portal (letting in more K) while closing the original portal. Process continues down axon to the axon terminal. Terminal buttons turns electrical charge into chemical (neurotransmitter) and shoots message to next neuron across the synapse.

Neuron firing like a Toilet 1. Like a Neuron, a toilet has an action potential. When you flush, an impulse is sent down the sewer pipe

Neuron firing like a Toilet 2. Like a neuron, a toilet has a refractory period. There is a short delay after flushing when the toilet cannot be flushed again because the tank is being refilled

Neuron firing like a Toilet 3. Like a Neuron, a toilet has a resting potential. The toilet is charged when there is water in the tank and it is capable of being flushed again 4. Like a Neuron, a toilet operates on the all-or-none principle it always flushes with the same intensity, no matter how much force you apply to the handle

All-or-None Principle The principle that if a neuron fires it will always fire at the same intensity All action potentials are of the same strength. A neuron does NOT fire at 30%, 45% or 90% but at 100% each time it fires.

Module 7: Neural and Hormonal Systems Communication Between Neurons

Synapse The tiny, fluid filled gap between the axon terminal of one neuron and the dendrite of another neuron The action potential cannot jump the gap

Neurotransmitters A chemical messenger that travels across the synapse from one neuron to the next Can influence whether the second neuron will generate an action potential or not

Neurotransmitters

Common Neurotransmitters & Functions Neurotransmitter Function Examples of Malfunctions Acetylcholine (ACh) Dopamine Serotonin Norepinephrine GABA (gamma aminobutyric acid) Muscle action, learning, memory Movement, learning, emotion, attention Mood, hunger, sleep, arousal Controls alertness & arousal Major inhibitory NT Deterioration assoc with Alzheimer s disease Excess receptors assoc with Schizophrenia; Lack produces Pakinson s disease Undersupply linked to depression; Prozac used to raise levels Undersupply can depress mood Undersupply linked to seizures, tremors, insomnia Glutamate Major excitatory NT Oversupply produces migraines/seizures.

Excitatory Effect A neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential (impulse) The second neuron is more likely to fire.

Inhibitory Effect A neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential (impulse) The second neuron is less likely to fire.

Threshold The level of stimulation required to trigger a neural impulse.

How drugs alter neurotransmitters Affected at the synapses by either blocking or amplifying NT activity. AGONIST- amplify normal sensations of arousal or pleasure ANTAGONIST- block NT functioning; can cause paralysis

Human Neuron Party I need 5 volunteers

How Neuron s work video http://www.youtube.com/watch?v=fr4s1 BqdFG4&feature=related

Neuron Dance Everyone stand up and line up around the room. Explain neuron parts as body parts. Do the Neuron WAVE!!!!!! Key points: Don t touch each other Don t fire till it reaches you! Say each neuron part as action potential reaches the proper part

Module 7: Neural and Hormonal Systems Neural Communication: The Neural Chain

Receptor Cells Specialized cells in the sensory systems of the body that can turn other kinds of energy into action potentials that the nervous system can process Receptor cells in the eye turn light into a neural impulse the brain understands.

Sensory Nerves (aka AFFERANT) Nerves that carry information to the central nervous system Connect the sense organs to the brain and spinal cord

Interneurons Nerve cells in the brain and spinal cord responsible for processing information related to sensory input and motor output

Motor Nerves (aka EFFERANT) Nerves that carry information from the central nervous system Carries messages from the brain and spinal cord to other parts of your body

A Neural Chain

Module 7: Neural and Hormonal Systems The Structure of the Nervous System

Who wants some $$$$$??? I ll give you the dollar if you can catch it! What does this demonstrate about our Nervous System???

The Nervous System

Central Nervous System (CNS) The brain and spinal cord The brain is the location of most information processing. The spinal cord is the main pathway to and from the brain.

Spinal Cord