Biological School

Nervous System

• Starts with the neuron

Firing Methods

• Resting Charge - Slightly neg charge
• Reach threshold if enough neurons reach dendrites
• Go into Action Potential (firing)

All or None Response - Fires or not; no in-between

Neurotransmitter - Chemical messages released by terminal buttons

• Acetylcholine (ACH) - Motor movement and memory. Less = risk of Alzheimer's
• Dopamine - Motor movement and alertness. Less = Parkinson's  /  Excess = Schizophrenia
• Serotonin - Mood control. Less = Clinical depression
• Endorphins - Pain control. Addictive drugs deal with endorphins.
• Norepiinephrine - Alertness and arousal. Less = Depression  /  Excess = Mania
• GABA (gamma-aminobutyric acid) - Major inhibitory neurotransmitters. Less = Tremors, seizures, and isomnia.
• Glutamate - Major excitatory neurotransmitter; involved in memory. Excess = Migraines (MSG avoidance)

Types of Neurons

• Sensory - Take information from the senses to the brain
• Inter - Messages from sensory neurons to other parts of brain or to motor
• Motor - Send info from brain to body

Types of Nervous Systems

• Central - Spine and Brain
• Peripheral - Nerves outside of bone; somatic and autonomic
• Somatic - Voluntary muscle movement, uses motor neurons
• Autonomic - Automatic functions (Sympathetic, Parasympathetic)
• Sympathetic - Fight or flight, heart rate up, breathing up, pupil dilation, slow digestion
• Parasympathetic - Slows after event, heart rate down, breathing down, pupils constrict, speeds digestion.
• Reflex - Sensory take info up thru spine to brain. Reactions when sensory reach spinal cord.

Endocrine System - System of glands that secrete hormones (Like neurons, but slower)