Parts of Neurons/Neuron Communication - Unit 2 AP Psych

Neurons

Nerve cell, building block of the nervous system.

Sensory/afferent neurons

Feel

Interneuron

Interpret

Motor/efferent neuron

Move

Dendrites

The bushy extensions of a neuron that receive chemical messages.

Soma

Cell body: Contains nucleus; DNA, genetics, etc.

Axon

The extension of a neuron through which neural electrical messages pass.

Myelin Sheath

Layer of fatty (lipid) tissue on the axon that protects/insulates the axon and speeds neural impulse (the message). Made of glial cells. 

Axon Terminal Branches

Branches at the end of an axon that send messages to the dendrites of another neuron. 

Resting Potential

The electrical charge of a neuron at rest (-70 MV [millivolts])

Threshold

The level of stimulation required to trigger an action potential (all or nothing)

-55 MV (millivolts).

Graded Potential

Weak stimulus (below -55 MV), NO action potential.

Action Potential

Neuron goes into action after a strong stimulus occurs; a neural impulse in the form of a brief electrical charge that travels down the axon.

Synapse

The junction between neurons.

Synaptic Gap

Place where axon terminals meet the dendrites, less than a millionth of an inch wide. 

Neurotransmitters

Chemical messengers that travel across the synaptic gap between neurons. 

Receptor Sites (Parking Spots)

Lock-and-key relationship between a neurotransmitter and its receptor site on a dendrite. 

Excitatory

Excite the cell/cause the neuron to fire, send signals that stimulate the brain.

Ex. Dopamine, glutamate.

Inhibitory

Inhibit (stop) cell firing, send signals to calm down the brain and create balance. 

Ex. Serotonin, GABA

Agonists

Drugs that occupy receptors and activate them.

Antagonists

Drugs that occupy receptors but do not activate them. They block receptor activation by agonists. 

Reuptake

The reabsorption of excess neurotransmitters by the neuron that released it. 

Neural Networks

Neurons cluster to work in groups to produce shorter, faster connections; continued simulation allows networks to strengthen. 

Biologial Psychology

A branch of psychology concerned with the links between biology, mental processes, and behavior.

Phrenology

Theory that the shape and bumps on the skull could reveal mental abilities and character traits. This is considered quackery, AKA fraudulent medical practice.