Nervous System Divisions
This division of the nervous system consists only of the brain and the spinal cord.
Central Nervous System/CNS
Taken from the root word for "body," this is the central part of the neuron that contains the nucleus.
Soma
This is the most common neuron shape in the brain, featuring one long axon and a "forest" of dendrites.
Multipolar neuron
When a neuron is "at rest" and not firing, its internal CHARGE is generally this.
Negative
This is the tiny, microscopic gap where two neurons meet but do not actually touch.
Synaptic Gap
This specific branch of the Autonomic Nervous System is active when you are "resting and digesting."
Parasympathetic Division
These branch-like structures are the "receivers" that pick up signals from other neurons.
Dendrite
This neuron type has its soma "off to the side," allowing sensory signals to bypass the cell body for maximum speed.
Unipolar neuron
To trigger an "All-or-None" response, a stimulus must be strong enough to reach this specific level.
Threshold (-55mV)
These are the chemical messengers, like Dopamine or Serotonin, that "jump the gap" to deliver a message.
Neurotransmitters
These are the nerves that branch off the spinal cord and carry messages to the rest of the body.
Peripheral Nervous System/PNS
This waxy, insulating layer wraps around the axon to increase the speed of the electrical signal.
Myelin Sheath
This rare, symmetrical neuron type is found only in special sense organs like the retina of the eye.
Bipolar neuron
During Depolarization, these ions rush into the cell, causing the internal charge to become positive.
Sodium ions/Na+
This type of drug mimics a neurotransmitter to "turn on" or activate a receptor.
Agonist
If you decide to kick a soccer ball, you are using this voluntary branch of the Peripheral Nervous System.
Somatic Nervous System
These are the specialized neuroglia cells that create myelin.
Schwann Cells
While neurons carry the signals, these "biological glue" cells make up 90% of your nervous system and provide support and protection.
Neuroglia
This active transport mechanism uses energy to move ions back to their original sides to reset the neuron for the next signal.
Sodium-Potassium Pump
This type of drug, such as Narcan or an Antihistamine, blocks a receptor to prevent a signal from being received.
Antagonist
This division is responsible for the "Fight or Flight" response, increasing heart rate and redirecting blood flow during stress.
Sympathetic Division
These are the tiny, exposed gaps in the myelin sheath where the electrical signal "jumps" to travel faster.
Nodes of Ranvier
Using "Form meets Function," explain why 99% of brain neurons are multipolar rather than unipolar.
Because they need to integrate/process information from many different sources at once
This term describes the period AFTER a "spike" where Potassium rushes out of the cell to restore the negative charge.
Repolarization
SSRIs (like Prozac) treat depression by blocking this process, which normally sucks neurotransmitters back into the sending neuron.
Reuptake