Fundamentals of the nervous system

Nervous system

The master controlling and communicating system of the body that allows cells to communicate via electrical and chemical signals.

Sensory input

The function of the nervous system that involves receiving information from sensory receptors about internal and external changes.

Integration

The function of the nervous system that involves processing and interpreting sensory input.

Motor output

The function of the nervous system that involves activating effector organs (muscles and glands) to produce a response.

Central nervous system (CNS)

The principal part of the nervous system that includes the brain and spinal cord and serves as the integration and control center.

Peripheral nervous system (PNS)

The portion of the nervous system outside the CNS that consists mainly of nerves extending from the brain and spinal cord.

Sensory division

The functional division of the PNS that conveys impulses from sensory receptors to the CNS.

Motor division

The functional division of the PNS that transmits impulses from the CNS to effector organs.

Neurons

The hallmark cells of nervous tissue that receive, process, transmit, and exchange information through electrical signals.

Synapses

Points of cell-cell communication between neurons through chemical signals (neurotransmitters).

Glia cells

Non-neuronal cells in the CNS that support and regulate the function of neurons and the nervous system.

Astrocytes

Glia cells that fill the space between neurons, influence neurite formation, and control the chemical content of the extracellular space.

Schwann Cells

Glia cells found in the PNS that form electrical insulation around neurons by wrapping membrane layers around neurites.

Oligodendrocytes

Glia cells found in the CNS that interact with multiple neurons and form insulating myelin sheaths around nerve fibers.

Microglial cells

Glia cells that function as phagocytes and clean up debris in the nervous system.

Neurites

The cellular processes of neurons, including axons and dendrites, which allow for communication and signal transmission.

Dendrites

The postsynaptic "input" side of a neuron that receives presynaptic chemical signals and conveys incoming messages toward the cell body.

Axon

The presynaptic "output" side of a neuron that transports electrical signals to postsynaptic target cells.

Synaptic transmission

The transfer of information between neurons across the synaptic cleft through the release and diffusion of neurotransmitters.

Neurotransmitters

Messenger molecules released by presynaptic neurons that bind to receptors on postsynaptic cells and generate electrical signal responses.