Lecture Notes on Nerve Physiology

These flashcards cover key vocabulary and concepts from the lecture notes on nerve physiology, including definitions of critical terms related to the nervous system, neuron structure, signal transmission, and synaptic communication.

Central Nervous System (CNS)

Consists of the brain and spinal cord, responsible for processing information and controlling bodily functions.

Peripheral Nervous System (PNS)

Includes all the nerves and ganglia outside of the CNS, responsible for transmitting signals to and from the CNS.

Neuron

The basic functional unit of the nervous system that transmits signals through electrical impulses.

Dendrites

Branch-like structures of a neuron that receive signals from other neurons.

Axon

A long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.

Myelin Sheath

A fatty layer that surrounds the axon, providing insulation and speeding up signal transmission.

Action Potential

A rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane.

Resting Membrane Potential

The voltage difference across a cell membrane when the cell is at rest, typically -70mV.

Neurotransmitter

Chemical messengers released by neurons to communicate with target cells.

Synapse

The junction between two neurons where neurotransmitters are released to transmit signals.

Excitatory Postsynaptic Potential (EPSP)

A postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A postsynaptic potential that makes a neuron less likely to fire an action potential.

Threshold

The minimum depolarization required for a neuron to fire an action potential.

Absolute Refractory Period

The period during which a second action potential cannot be initiated, regardless of the stimulus strength.

Relative Refractory Period

A period following the absolute refractory period during which a stronger than normal stimulus is needed to elicit an action potential.

Regeneration of Neurons

The process by which neurons can repair themselves and regenerate after injury, more common in PNS than CNS.

Spatial Summation

When multiple presynaptic neurons simultaneously stimulate a postsynaptic neuron, leading to an action potential.

Temporal Summation

The addition of multiple stimuli from a single presynaptic neuron over time to produce an action potential.

Glial Cells

Supportive cells in the nervous system that provide structure, insulation, and protection for neurons.

Oligodendrocytes

CNS glial cells that form the myelin sheath around axons.

Astrocytes

Star-shaped glial cells in the CNS that manage the blood-brain barrier, nutrient support, and neurovascular communication.

Microglia

The resident immune cells of the CNS that remove debris and modulate inflammation.

Schwann Cells

PNS glial cells that wrap around axons to form the myelin sheath and aid in regeneration.

Satellite Cells

PNS glial cells that surround neuron cell bodies in ganglia, providing structural support and regulating the external chemical environment.

Major Types of Neurotransmitters

Include amino acids (e.g., glutamate, GABA), monoamines (e.g., dopamine, serotonin), peptides, and acetylcholine, involved in various brain functions.

Neural Circuits

Functional groups of neurons that process specific types of information and perform particular functions within the nervous system.

Local Potential (Graded Potential)

A small, transient change in the membrane potential that can vary in amplitude and duration, typically occurring at dendrites or the cell body.

Reuptake

The process by which neurotransmitters are reabsorbed by the presynaptic neuron after release into the synaptic cleft, terminating their signal.