Functional Organization of Nervous Tissue

These flashcards include key terms and definitions related to the functional organization of nervous tissue, focusing on aspects of the nervous system, neuron structure and function, and communication processes.

Neuron

Electrically excitable cells in the nervous system responsible for transmitting signals.

Glial cell

Supportive cells in the nervous system that perform various functions including maintaining homeostasis and protection.

Central Nervous System (CNS)

Consists of the brain and spinal cord; the main control center of the body.

Peripheral Nervous System (PNS)

Comprises all nerve tissues outside of the CNS, including sensory and motor neurons.

Homeostasis

The process by which a stable internal environment is maintained by the body.

Action potential

An electrical impulse that travels along the axon of a neuron.

Synapse

The junction between two neurons where communication occurs.

Neurotransmitter

Chemical messengers released from presynaptic neurons that transmit signals across synapses to postsynaptic cells.

Afferent Division

Part of the PNS that transmits sensory information to the CNS.

Efferent Division

Part of the PNS that carries motor commands from the CNS to effectors like muscles and glands.

Glial Cells: Astrocytes

Star-shaped glial cells that regulate blood-brain barrier and maintain brain fluid composition.

Glial Cells: Oligodendrocytes

Cells that produce myelin sheaths around axons in the CNS.

Myelin sheath

Protective covering that surrounds the axon, speeding up the transmission of signals.

Depolarization

The process by which the inside of a cell becomes more positive, often leading to an action potential.

Hyperpolarization

The process by which the inside of a cell becomes more negative than the resting potential.

Refractory Period

The time during which a neuron is unable to fire another action potential.

Graded potential

A localized change in membrane potential that can vary in amplitude.

Spatial Summation

The process by which multiple synaptic inputs at different locations combine to produce a greater effect.

Temporal Summation

The process by which multiple signals in rapid succession add together to produce a greater effect.

Presynaptic Inhibition

Reduction in the amount of neurotransmitter released from a presynaptic neuron.

Neuromodulation

The process by which a neuron uses neurotransmitters to control a variety of neuronal systems.