Central Nervous System and Synaptic Transmission

Vocabulary flashcards covering resting and action potentials, synaptic structures, neurotransmitters, nervous system divisions, cortical areas, and white matter tracts based on the lecture transcript.

Resting Membrane Potential

The electrical potential across a neuron's membrane when at rest, starting out at around $-70\text{ millivolts}$.

Graded Potential

A membrane potential change that occurs when incoming stimuli do not reach the threshold required to trigger an action potential.

Synapse

A functional junction that connects neurons or links a neuron to a muscle cell (neuromuscular junction) to mediate information transfer.

Axosomatic Synapse

A junction where the axon terminal of one neuron connects directly to the soma (cell body) of another neuron.

Gap Junctions

Microscopic openings in the cell membrane that transmit signals directly between cells and permit two-way communication.

Hippocampus

A brain region involved in memory and emotions that features neurons communicating via gap junctions.

Summation

The process of adding together multiple excitatory and inhibitory postsynaptic potentials (temporally or spatially) to reach the threshold for an action potential.

EPSP (Excitatory Postsynaptic Potential)

A graded electrical signal produced by neurotransmitters that makes the generation of an action potential more likely.

IPSP (Inhibitory Postsynaptic Potential)

A graded electrical signal that prevents or reduces the likelihood of an action potential firing.

Indolamines

A group of neurotransmitters comprising serotonin and histamine, whose imbalances (particularly serotonin) are associated with mental illnesses.

Peripheral Nervous System (PNS)

The portion of the nervous system consisting of all neural structures located outside of the brain and spinal cord.

Primary Somatosensory Cortex

A cortical region that determines where the body and its parts are located in space based on incoming sensory signals.

Proprioceptors

Sensory receptors that communicate spatial orientation and movement, such as indicating that an arm is flexed or a foot is resting on the ground.

Vestibular Cortex

A sensory area of the cerebral cortex that is technically located within the insula.

Prefrontal Cortex

An anterior cortical area responsible for personality, working memory, reasoning, judgment, and persistence.

Posterior Association Area

A region spanning the temporal, parietal, and occipital lobes that aids in recognizing patterns, spaces, and body positioning.

Wernicke Area

A functional brain area within the posterior association area involved in understanding both written and spoken language.

Association Fibers

White matter tracts that interconnect different cortical regions within the same cerebral hemisphere.

Commissural Fibers

White matter tracts that cross between the left and right cerebral hemispheres, exemplified by the corpus callosum.

Corpus Callosum

A major tract of commissural fibers responsible for connecting and transmitting information between the two cerebral hemispheres.