Biological School

Biological School

The Nervous System:

• Neuron- Individual nerve cell

How does a Neuron Fire?

• Resting Potential: slightly negative charge
• Reach the threshold when enough neurotransmitters reach dendrites
• Important that neurons don’t misfire, otherwise body will not receive messages
• Electrochemical Process
• Electrical inside the neutron
• Chemical outside the neuron (in the synapse in the form of a neurotransmitter)
• Firing is called Action Potential
• All-or None Response
• The idea that either the neuron fires or it does not- no part way firing
• Like a gun

Neurotransmitters

• Chemical messengers released by terminal buttons released through the synapse

Types of Neurotransmitters

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

Drugs

• Can Be Two Things:
• Agonists- Make neuron fire
• Antagonists- Stop neural firing

Types of Neurons

• Sensory Neurons (Afferent Neurons)
• Take information from the senses to the brain
• Inter Neurons
• Take messages from Sensory Neurons to other parts of the brain or to Motor Neurons
• Motor Neurons
• Take information from brain to the rest of the body