Central Nervous System

• Brain

• Spinal Cord

Neurons, Hormones, and the Brain

• Explain why we feel

• Two main divisions of the human nervous system are:

  • Central

  • Peripheral

Somatic

• Connects our sensory receptors to the skeletal muscles that allow voluntary movement

• When a bug lands on your arm you swat it

Automatic

• Regulates internal organs

• When you are nervous your glands may produce sweat

• The autonomic is also divided into two:

  • Sympathetic

  • Parasympathetic

Sympathetic

• Mobilized bodily resources that increase energy

Parasympathetic

• It operates during relaxed states and conserves energy

• Think of a parachute slowing down and skydiver

Neuron Structure

• Neurons do not touch each other

• The space in between is called the synapse

• Neurotransmitter enters synapse, binds to receptors that it fits

• Dendrites are the part of a neuron that is tree-like or “branchy”

• Gilla cells hold neurons in place

Major Neurotransmitters

• Dopamine

• Acetylcholine (ACH)

• Norepinephrine

• Serotonin

• Endorphins

• GABA

• Glutamate

Dopamine

• alertness motor movement

• Lack of Dopamine leads to Parkinson’s disease

• Too much leads to Schizophrenia

ACH

• ACH - motor movement

• Lack of ACH = Alzheimer’s

GABA

• Inhibiting

• Regulates amount of neurotransmitters that should be involved in the reuptake process

• Slows down information

• Action potential - when neuron fires all or nothing firing

Glutamate

• Exciting

• Sparks neurotransmitter to allow transmission to continue

Serotonin

• Neurotransmitter that is targeted by doctors for depression

• Medication that is used are called antidepressants SSRI

NT’s play multiple roles

• Tylenol

Multiple jobs that they do

Neural regeneration

• The ability of neurons to grow back after injury or damage

Stem cells

• Immature cells that renew themselves and have the potential to develop into mature cells

Afferent

• Sensory neurons

Receive info Outside back in to CNS

Efferent

• Motor neurons

• Brain tells peripheral system, spinal cord to PNS