Neurons:
● Neurons- brain cells that specialize in communication with each other
● 86 billion in the brain
● Differently shaped compared to other cells in the body
● Made up of:
A) cell body (soma)
- Center of neuron; builds new connections
- Nucleus
B) Dendrites
- look like tree branches
- Receive info from other neurons
C) Axons
- tails of the neuron
- Activated by incoming signals
D) Axon terminal
- at the end of axon filled with NTs
E) Myelin sheath
- fatty protein that forms around neuron
- Helps neurons communicate quickly
- Made up of individual sections separated by nodes
F) Neurotransmitters
- chemical messengers that allow neuron to neuron communication
, G) Synapse
- space between where NTs travel
- Each neuron has 1,000-10,000 synapses
Glial cells:
● play role in myelin sheath formation and the blood-brain barrier
● One types are astrocytes (blood flow to brain, development of embryo) and
oligodendrocytes (new connections, release chemicals for healing)
Electrifying thought:
● neurons respond to NTs through electrical thought
● When no NTs act on neuron it is at resting potential
● Neurons can fire one hundred to one thousand times per second
Chemical communication:
● inside neurons communication is chemical
● Hormones, serotonin, dopamine
● Some NTs excite nervous system and some nhibit
● Glutamate and GABA are the most common in CNS
- glutamate is excitatory and incr the chance neurons will communicate
- GABA is inhibitory
● agonists— increase NT activity
● Antagonists— decrease NT activity