BioScience Dictionary

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 | Ot.

Found Brain 133 times.

Displaying results 1 to 10.

1. Acetylserotonin
An acetylated (has a CH3CO- group attached) form of the hormone serotonin . Along with serotonin and the hormone melatonin , it is produced in the pineal gland in the brain .

2. Afferent
Moving or carrying inward or toward a central part. Refers to vessels, nerves, etc. For example, blood vessels carrying blood toward the heart, or nerves conducting signals to the brain. Compare efferent.

3. Alzheimer's disease
Alzheimer's disease is a form of senile dementia of unknown origin that has characteristic pathologic changes in the brain. Its onset is slow and at an earlier age than the common dementia. After onset, it progresses steadily and the pathology is more severe than the average form of senile dementia. Most studies report that this disease is responsible for the cognitive decline in about 50% of demented older adults.

4. Alzheimer's disease (AD)
A progressive, neurodegenerative disease characterized by loss of function and death of nerve cell s in several areas of the brain leading to loss of cognitive function such as memory and language. The cause of nerve cell death is unknown. Alzheimer's disease is the most common cause of dementia .

5. Amyotrophic lateral sclerosis
This is the most frequent form of the progressive nerve disorders affecting the brain , brain stem and spinal cord, usually appearing when a person is 50-70 years old. It is sometimes associated with dementia and Parkinson's disease .

6. Anencephaly
A condition where the brain fails to develop and may be only partially present or completely absent.

7. Aneurysm
This is a localized dilatation of the lumen of a blood vessel. The most common sites of aneurysms are the aorta and the vessels of the brain.

8. Beta-amyloid
The protein which forms thick deposits, or plaques, in the brains of people with Alzheimer's disease, a disease where memory skills gradually deteriorate with age.

9. Biofeedback
A technique that allows a person to control, via methods such as visualization and relaxation, internal processes (such as heartbeat, blood pressure, brain wave activity. etc.) that are normally outside conscious control.

10. Blood-brain barrier
A barrier made up of neuroglia and capillary walls which limits the movement of substances in the bloodstream into the brain .

View web definitions »

Learn more about Brain »