Brain Basics

Cerebrum

The largest part of the human brain divided into two separate hemispheres.

Corpus Callosum

The largest bundle of nerve fibers that forms a bridge between the left and right cerebral hemispheres.

Cerebral Cortex

A deeply folded layer of nerve tissue on the surface of the cerebrum that increases processing power.

Frontal Lobes

Regions at the front of the brain responsible for voluntary movement

Parietal Lobes

Regions at the top of the brain that integrate sensory signals from the skin and process taste and some visual information.

Occipital Lobes

Regions at the back of the brain responsible for processing visual information including colors and shapes.

Temporal Lobes

Regions on the sides of the brain that interpret auditory information and carry out some visual processing.

Hippocampus

A curved structure within the temporal lobes that is essential for encoding new memories.

Amygdala

A deep structure in the temporal lobe that integrates memory and emotion and plays a role in emotional learning.

Limbic System

A group of deep brain structures including the hippocampus and amygdala that help regulate emotion and motivation.

Thalamus

A structure that integrates sensory information and relays it to other parts of the brain.

Hypothalamus

A structure that monitors the autonomic nervous system and sends hormonal signals via the pituitary gland.

Forebrain

A region of the developing brain that becomes the cerebral hemispheres and major parts of the limbic system.

Midbrain

Sits beneath the thalamus and coordinates eye movements and triggers reflexes to sounds.

Basal Ganglia

A collection of structures that help regulate complex body movements and motor skill learning.

Hindbrain

The most posterior part of the brain comprising the pons

Cerebellum

The second-largest brain structure that coordinates voluntary movements and helps the brain learn new motor skills.

Pons

A part of the hindbrain that influences breathing and posture and serves as a route for information to the spinal cord.

Medulla

Part of the hindbrain that carries nerve pathways to the spinal cord and controls basic functions like heart rate and breathing.

Brainstem

The collective term for the midbrain

Nerve Tracts

Distinct bundles of region-spanning neurons that transmit signals over long distances.

Neural Network

A group of nerve tracts connecting a series of brain regions to route

Excitatory Neurons

Neurons that send signals that push their neighbors toward firing; they make up about 80 percent of brain neurons.

Inhibitory Neurons

Neurons that suppress the activity of neighboring neurons to tune and smooth signals within a circuit.

Neuron

The functional unit of the nervous system; a specialized cell that transmits electrical signals.

Dendrites

Branched projections from the cell body that receive signals from other neurons at synapses.

Axon

The long fiber-like extension of a neuron by which it sends information to target cells.

Action Potential

An electrical charge that travels along the axon to trigger the release of a neurotransmitter.

Glia

Specialized cells that nourish and support neurons.

Astrocytes

Star-shaped glial cells that nourish neurons