Neuroscience

Neurons

Neurons

information carrying cells

Glia Cells

maintain chemical environment in neurons

Myelin

A white, fatty, waxy coating to protect the neuron and speed up the neural signal it sends

Dendrites

receives incoming signals from other neurons

Axon

carries signals away from cell body

Myelin Sheath

myelin covered segments of the axon

Axon Bulb

at the end of each axon, contains storage pouches

Neurotransmitters

chemical messengers

Synapse

the junction between two neurons or between a neuron and a muscle

Presynaptic Neuron

first neuron that does not touch the second (sender)

Postsynaptic Neuron

second neuron receiving information

Synaptic Gap

measurable distance between pre and postsynaptic neurons

Sodium (Na+) and Potassium (K)

Important for sending signals

Resting Potential

difference that exists when neuron is at rest

Action Potential

signal that gets sent to complete an action

Threshold of Excitation

potential difference at which a neuron will fire an action potential

All-or-None Law

if stimuli were to increase, it wouldn't affect the response

Refractory Period

neuron returns to resting potential, another action potential cannot happen

Synaptic Transmission

action potential reaches axon bulb releasing neurotransmitters

Excitation

neurotransmitter makes postsynaptic cell MORE likely to fire action potential

Inhibition

neurotransmitter makes postsynaptic cell LESS likely to fire action potential

Enzymes

chemical that breaks down molecules + neurotransmitters

Central Nervous System

the portion of the vertebrate nervous system consisting of the brain and spinal cord

Nervous System

interconnected network of all neurons in the body

Peripheral Nervous System

division of the nervous system containing all the nerves that lie outside of the CNS

Sensory Neuron

a neuron conducting impulses INWARDS to the brain or spinal cord

Motor Neuron

a neuron conducting impulses OUTWARDS from the brain or spinal cord

Somatic Nervous System

neurons that control out muscles for voluntary actions

Automatic Nervous System

controls smooth muscles of internal organs, heart, and glands

Parasympathetic

Operates under calm conditions

Sympathetic

Activates under conditions of threat or stress to protect us from danger