Unit 1.3: The Neuron and Neural Firing Flashcards
(22 cards)
Glial Cells
Non-neuronal cells that provide support, structure, insulation, and help with waste transport and communication in the nervous system. Do not process or send information.
Neuron
The basic functional unit of the nervous system that transmits information via electrical impulses and chemical signals.
Sensory Neuron (Afferent)
Neurons that carry information from sensory receptors to the central nervous system (CNS).
Interneuron
Neurons found in the brain and spinal cord that connect sensory and motor neurons.
Motor Neuron (Efferent)
Neurons that carry signals from the CNS to muscles to produce movement.
Reflex Arc
A neural pathway that controls a reflex action without brain involvement; includes sensory neuron, interneuron, and motor neuron.
Resting Potential
The state of a neuron when it is not firing; inside of the neuron is negatively charged compared to the outside.
Threshold
The level of stimulation required to trigger an action potential in a neuron.
Action Potential
A brief electrical charge that travels down the axon when a neuron fires.
Depolarization
The process during which the inside of a neuron becomes more positive, initiating an action potential.
Repolarization
The return of the neuron to a resting state after an action potential.
Refractory Period
A short period after an action potential during which the neuron cannot fire again.
Synapse
The junction between two neurons where communication occurs.
Presynaptic Neuron
The neuron that sends the chemical signal (neurotransmitter).
Postsynaptic Neuron
The neuron that receives the neurotransmitter signal.
Synaptic Gap (Cleft)
The tiny space between the axon terminal of one neuron and the dendrites of another.
Neurotransmitter
Chemical messenger released by neurons to transmit signals across a synapse.
Reuptake
The process of reabsorbing unused neurotransmitters back into the presynaptic neuron.
Excitatory Neurotransmitter
A neurotransmitter that increases the likelihood of the postsynaptic neuron firing (causes depolarization).
Inhibitory Neurotransmitter
A neurotransmitter that decreases the likelihood of the postsynaptic neuron firing (causes hyperpolarization).
Multiple Sclerosis
A neurological disorder in which the immune system damages the myelin sheath, disrupting neural communication.
Myasthenia Gravis
A disorder where antibodies block acetylcholine receptors, leading to muscle weakness.
