Brain Health Science

Brain Science Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

ADRENAL CORTEX
An endocrine organ that secretes corticosteroids for metabolic functions; for example, in response to stress.
ADRENAL MEDULLA
An endocrine organ that secretes epinephrine and norepinephrine in concert with the activation of the sympathetic nervous system; for example, in response to stress.
AMYGDALA
A structure in the forebrain that is an important component of the limbic system and plays a central role in emotional learning, particularly within the context of fear.
AUDITORY NERVE
A bundle of nerve fibers extending from the cochlea of the ear to the brain that contains two branches: the cochlear nerve, which transmits sound information, and the vestibular nerve, which relays information related to balance.
AUTONOMIC NERVOUS SYSTEM
A part of the peripheral nervous system responsible for regulating the activity of internal organs. It includes the sympathetic and parasympathetic nervous systems.
AXON
The fiber like extension of a neuron by which it sends information to target cells.

B

BASAL GANGLIA
Clusters of neurons, which include the caudate nucleus, putamen, globus pallidus, and substantia nigra, located deep in the brain that play an important role in the initiation of movements. Cell death in the substantia nigra contributes to Parkinson's disease.
BRAIN RESERVE
The build of synaptic connections in the brain.
BRAINSTEM
The major route by which the forebrain sends information to and receives information from the spinal cord and peripheral nerves. The brainstem controls, among other things, respiration and the regulation of heart rhythms.
BROCA'S
AREA The brain region located in the frontal lobe of the left hemisphere that is important for the production of speech.

C

CEREBELLUM
A large structure located at the roof of the hindbrain that helps control the coordination of movement by making connections to the pons, medulla, spinal cord, and thalamus. It also may be involved in aspects of motor learning.
CEREBRAL CORTEX
The outermost layer of the cerebral hemispheres of the brain. It is largely responsible for all forms of conscious experience, including perception, emotion, thought, and planning.
CEREBRAL HEMISPHERES
The two specialized halves of the brain. For example, in right-handed people, the left hemisphere is specialized for speech, writing, language, and calculation; the right hemisphere is specialized for spatial abilities, visual face recognition, and some aspects of music perception and production.
CEREBROSPINAL FLUID
A liquid found within the ventricles of the brain and the central canal of the spinal cord.
COGNITION
The process or processes by which an organism gains knowledge or becomes aware of events or objects in its environment and uses that knowledge for comprehension and problem-solving.
CONE
A primary receptor cell for vision located in the retina. It is sensitive to color and is used primarily for daytime vision.
CORPUS CALLOSUM
The large bundle of nerve fibers linking the left and right cerebral hemispheres.

D

DENDRITE
A tree-like extension of the neuron cell body. The dendrite is the primary site for receiving and integrating information from other neurons.

F

FOREBRAIN
The largest part of the brain, which includes the cerebral cortex and basal ganglia. The forebrain is credited with the highest intellectual functions.
FRONTAL LOBE
One of the four divisions (the other lobes are the parietal, temporal, and occipital) of each hemisphere of the cerebral cortex. The frontal lobe has a role in controlling movement and in the planning and coordinating of behavior.

G

GLIA
Specialized cells that nourish and support neurons.
GRAY MATTER
Nerve tissue, esp. of the brain and spinal cord, that contains fibers and nerve cell bodies and is dark reddish-gray.
GROWTH CONE
A distinctive structure at the growing end of most axons. It is the site where new material is added to the axon.

H

HIPPOCAMPUS
A seahorse-shaped structure located within the brain and considered an important part of the limbic system. One of the most studied areas of the brain, it functions in learning, memory, and emotion.
HYPOTHALAMUS
A complex brain structure composed of many nuclei with various functions, including regulating the activities of internal organs, monitoring information from the autonomic nervous system, controlling the pituitary gland, and regulating sleep and appetite.

L

LIMBIC SYSTEM
A group of brain structures-including the amygdala, hippocampus, septum, basal ganglia, and others-that help regulate the expression of emotion and emotional memory.
LONG-TERM MEMORY
The final phase of memory, in which information storage may last from hours to a lifetime.

M

MEMORY CONSOLIDATION
The physical and psychological changes that take place as the brain organizes and restructures information to make it a permanent part of memory.
MIDBRAIN
The most anterior segment of the brainstem. With the pons and medulla, the midbrain is involved in many functions, including regulation of heart rate, respiration, pain perception, and movement.
MOTOR NEURON
A neuron that carries information from the central nervous system to muscle.
MYELIN
Compact fatty material that surrounds and insulates the axons of some neurons.

N

NEURON
A nerve cell specialized for the transmission of information and characterized by long, fibrous projections called axons and shorter, branchlike projections called dendrites.
NEUROGENESIS
A process of generating new nerve tissue.
NEUROPLASTICITY
A general term used to describe the adaptive changes in the structure or function of nerve cells or groups of nerve cells in response to injuries to the nervous system or alterations in patterns of their use and disuse.
NOCICEPTORS
In animals, nerve endings that signal the sensation of pain. In humans, they are called pain receptors.

O

OCCIPITAL LOBE
One of the four subdivisions of the cerebral cortex. The occipital lobe plays a role in processing visual information.

P

PARASYMPATHETIC NERVOUS SYSTEM
A branch of the autonomic nervous system concerned with the conservation of the body's energy and resources during relaxed states.
PARIETAL LOBE
One of the four subdivisions of the cerebral cortex. The parietal lobe plays a role in sensory processes, attention, and language.
PERIPHERAL NERVOUS SYSTEM
A division of the nervous system consisting of all nerves that are not part of the brain or spinal cord.
PONS
A part of the hindbrain that, with other brain structures, controls respiration and regulates heart rhythms. The pons is a major route by which the forebrain sends information to and receives information from the spinal cord and peripheral nervous system.
PROGENITOR CELL
Progenitor cells, like stem cells, have a capacity to differentiate into a specific type of cell

R

RECEPTOR CELL
A specialized sensory cell, designed to pick up and transmit sensory information.
RECEPTOR MOLECULE
A specific protein on the surface of or inside a cell with a characteristic chemical and physical structure. Many neurotransmitters and hormones exert their effects by binding to receptors on cells.
ROD
A sensory neuron located in the periphery of the retina. The rod is sensitive to light of low intensity and is specialized for night time vision.

S

SHORT-TERM MEMORY
A phase of memory in which a limited amount of information may be held for several seconds or minutes.
SYMPATHETIC NERVOUS SYSTEM
A branch of the autonomic nervous system responsible for mobilizing the body's energy and resources during times of stress and arousal.
SYNAPSE
A physical gap between two neurons that functions as the site of information transfer from one neuron to another.

T

TEMPORAL LOBE
One of the four major subdivisions of each hemisphere of the cerebral cortex. The temporal lobe functions in auditory perception, speech, and complex visual perceptions.
THALAMUS
A structure consisting of two egg-shaped masses of nerve tissue, each about the size of a walnut, deep within the brain. The key relay station for sensory information flowing into the brain, the thalamus filters out information of particular importance from the mass of signals entering the brain.

V

VENTRICLES
Comparatively large spaces filled with cerebrospinal fluid. Of the four ventricles, three are located in the forebrain and one in the brainstem. The lateral ventricles, the two largest, are symmetrically placed above the brainstem, one in each hemisphere.

W

WERNICKE'S AREA
A brain region responsible for the comprehension of language and the production of meaningful speech.
WHITE MATTER
Nerve tissue, esp. of the brain and spinal cord, which primarily contains myelinated fibers and is nearly white in color.