Nervous System
A body system that collects, interprets, and responds to stimuli from the environment.
Neuron
A nerve cell responsible for relaying information within the nervous system.
Sensory Neuron
A type of neuron that collects data about stimuli in the internal and external environment and sends the information to the brain.
Interneuron
A type of neuron in the central nervous system that receives incoming sensory information and relays information to motor neurons.
Motor Neuron
A type of neuron that communicates with gland or muscle cells which then carry out a response as determined by the brain.
The Three Types of Neuron
sensory neuron, interneuron, motor neuron
Dendrite
A part of a neuron that receives incoming information
Axon
A part of a neuron that conducts signals away from the cell body and on to another cell.
Input Zone
the location where information enters the neuron
Output Zone
the part of a neuron at which the cell sends information to another cell
Sodium-Potassium Pump
A protein embedded in the plasma membrane that actively transports sodium and potassium against their concentration gradients.
Resting Membrane Potential
The difference in the charge across a cell membrane which has the potential for an action potential to occur.
Action Potential
A nerve impulse.
Threshold
The minimum voltage shift across a membrane required for an action.
Trigger Zone
The part of the neuron located at the base of the cell body that initiates action potentials.
synapse
The gap between a neuron and a gland cell, muscle cell, and another neuron
Presynaptic Cell
The cell at a synapse that stores a neurotransmitter for release.
Postsynaptic Cell
The cell at a synapse to which the neurotransmitter binds.
Exciting Signals
Signals that trigger an action potential to happen.
Inhibiting Signals
Neurotransmitters that inhibit or prevent action potentials.
Botox
A bacterial toxin that is often used to smooth facial wrinkles
Nerve
A bundle of axons of neurons.
Myelin Sheath
An insulating layer that surrounds axons neurons in the nervous system and allows action potentials to propagate more quickly.
Central Nervous System (CNS)
Division of the nervous system that consists of the brain and spinal cord; is the processing center of the body, and contains interneurons.
Peripheral Nervous System (PNS)
Division of the nervous system that sends signals to and from the central nervous system and contains sensory and motor neurons.
Schwann Cells
The glial cells that compose the myelin sheath in the peripheral nervous system.
Reflex
An automatic movement of the body that occurs as a response to stimuli.
Somatic Nerves
nerves that carry signals to the head, the trunk, and the limbs
Autonomic Nerves
Motor neurons that innervate deeper organs and regulate unconscious organ activity. (Two categories)
Sympathetic Nerves
A division of the autonomic nerves which prepare the body for stressful situations by increasing physiological activity.
Parasympathetic Nerves
A division of the autonomic nerves which allow the body to recover from stressful situations by slowing down physiological activity.