Neurons: Types, Anatomy, and Functions in the Nervous System

Neurons

The fundamental units of the brain and nervous system, responsible for receiving sensory input, sending motor commands, and relaying electrical signals.

Neurogenesis

The process by which the brain makes new neurons, occurring in the hippocampus, lateral ventricles, and possibly amygdala.

Unipolar Neurons

Also known as sensory neurons, they have one axon and one dendrite branching off in opposite directions from the cell body.

Pyramidal Neurons

Neurons named after their pyramid-shaped cell body, having one axon and two main dendrite branches, passing signals inside the brain.

Multipolar Neurons

Neurons with one axon and many dendritic branches, carrying signals from the central nervous system to other body parts.

Bipolar Neurons

Neurons with one axon and one dendrite branch, passing signals from one neuron to the next inside the central nervous system.

Purkinje Neurons

Neurons found in the cerebellum, with one axon and a dense, complicated dendrite arrangement, controlling balance and coordination.

Sensory Neurons

Neurons that begin with dendrites receiving signals from the external environment, with long dendrites and short axons.

Interneurons

Neurons found only in the CNS that connect one nerve cell to another, relaying information between sensory and motor neurons.

Motor Neurons

Efferent neurons that carry information from the central nervous system to the periphery, responsible for all body movement.

Upper Motor Neurons

Neurons originating in the motor cortex or brain stem, transmitting signals to lower motor neurons and initiating voluntary movement.

Lower Motor Neurons

Neurons found in the brainstem and spinal cord that communicate directly with effector organs, stimulating muscle activity.

Dendrites

Branch-like projections of neurons that receive signals from the external environment.

Axon

The fiber that carries the signal away from the neuron cell body.

Soma

The cell body of a neuron, containing the nucleus and organelles.

CNS

Central Nervous System, consisting of the brain and spinal cord.

Efferent

Refers to neurons that carry information away from the central nervous system.

Signal Transmission

The process by which neurons communicate with each other and with muscles or glands.

Neuronal Communication

The process involving the transmission of signals between neurons, including sensory input and motor output.

Nerve Fiber

The long projection of a neuron that transmits signals.

Cell Body

The part of the neuron that contains the nucleus and is responsible for maintaining the cell.

Receptors

Specialized structures at the end of dendrites that receive signals from the environment.

Effector Organs

Organs such as muscles and glands that respond to signals from motor neurons.