Nervous System

The Nervous System

• Starts with an individual nerve cell called a NEURON.

Neuro-anatomy

• Synapse - a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

Neurotransmitters (chemicals held in terminal bottoms that travel through synaptic gaps.) 

This is a Neuron, with all of its parts labeled.

• Resting Potential: slightly negative charge
• Reach the threshold when enough neurotransmitters reach the dendrites

It is an Electrochemical process

• Electrical inside the neuron
• Chemical outside the neuron
• The firing is called Action Potential

All or Nothing Response

• The idea that either the neuron fires or it does not - no partway firing, like a gun

Neurotransmitters

• chemical messengers released by terminal buttons throughout the synapse

Types

Acetylcholine (ACH)

• Deals with motor movement and memory
• Lack of ACH has been linked to Alzheimer's disease

Dopamine

• Deals with motor movement and alertness
• Lack of Dopamine has been linked to Parkinson's disease
• Too much has been linked to schizophrenia 

Serotonin

• Involved in mood control 
• Lack of Serotonin has been linked to depression

Endorphins

• Involved in pain control
• Many of our most addictive drugs deal with Endorphins

Drugs

• Agonists- Makes neuron fire
• Antagonists- Stops neurons fire

Different Kinds of Neurons

• Sensory Neurons - take the info from the senses to the brain
• Inter Neurons - Takes messages from Sensory Neurons to the other parts of the brain
• Motor Neurons - Take information from the brain to the rest of the body