A mass in the wall of a blood vessel with a balloon like shape. As it grows, the wall surrounding it weakens which may lead it to burst resulting in a hemorrhage.

Autonomic Nervous System

The part of the nervous system that controls involuntary activities, including the heart. It is divided into the sympathetic and parasympathetic systems.



A nerve fiber that carries an impulse from the nerve cell to a target, and carries materials from the nerve terminals back to the nerve cell. .


The lower part of the brain that connects to the spinal cord. Functions located in the brainstem include those necessary for survival (breathing, heart rate) and for arousal (being awake and alert).

Central Nervous System

The Central Nervous System is composed of the brain and spinal cord.


The part of the brain that helps coordinate movement.

Closed Head Injury

Trauma to the head regardless of severity.


A violent non-penetrating injury to the brain. Often accompanied by loss of consciousness.


Fibers extending from a nerve cell (neuron) that acts as receptors for electrochemical nervous impulse transmissions.

Frontal Lobe

Front part of the brain; involved in planning, organizing, problem solving, selective attention, personality and a variety of "higher cognitive functions."


A mass of nervous tissue composed principally of nerve-cell bodies and lying outside the brain or spinal cord

Head Injury

Any traumatic injury to the head regardless of severity.


The collection of blood in tissues following rupture of a blood vessel. Can be epidural (outside the brain and its fibrous covering, but under the skull), subdural (between the brain and its fibrous covering) or intracerebral (in the brain tissue).


Abnormal internal or external discharge of blood.

Incomplete Injury (head injury)

Injury leaving some sensation or motor control below spinal cord lesion.

Major Head Injury

Trauma to the brain resulting in loss of consciousness.

Minor Head Injury

Trauma to the head that does not necessarily result in the loss of consciousness.

Open Head Injury

Trauma to the brain resulting in loss of consciousness due to the penetration of the brain.


Loss of function wherein the upper body retains most function and sensation. Paraplegia often results in near complete paralysis of the lower limbs; however, the degree of loss is variable.

Parietal Lobes

Areas of the brain that control spatial information (right lobe) and language (left lobe)

Post Concussion Syndrome

PCS includes impairments in the ability to think, act, and recall/learn information. PCS is characterized by unreliable memory, rapid mood swings, poor concentration, headache, dizziness, hypersensitivity, depression and anxiety.


Loss of function affecting all four limbs.


Microscopic lesions in the brain caused when the movement of the brain within the skull puts strain on delicate nerve fibers and blood vessels causing them to stretch to the point of breaking.


Junction between a neuron and another neuron or muscle cell for transferring brain signals, sensory inputs, etc., along the nervous system.

Temporal Lobes

There are two temporal lobes, one on each side of the brain, at about the level of the ears. They are crucial for short term memory along with smell and hearing.


A physical injury caused by violent or disruptive action

Traumatic Brain Injury (TBI)

An injury to the brain regardless of severity.


Injury to the neck from violent back and forth movement of the head and neck (such as in a rear end car collision). Such injuries can cause brain damage even without direct injury to the head.

Pathophysiology of TBI