Webster's New World Medical Dictionary

bradycardia
A slow heart rate, usually defined as
less than 60 beats per minute.
bradykinesia
Slow movement. Bradykinesia is
often associated with an impaired ability to adjust
the body’s position. Bradykinesia can be a symptom
of nervous system disorders, particularly
Parkinson’s disease, or a side effect of medications.
bradyphrenia
A slow thought process.
Bradyphrenia can be a side effect of certain psychi-
atric medications.
bradypnea
Abnormally slow breathing. A respira-
tory rate that is too slow. The normal rate of respira-
tions (breaths per minute) depends on a number of
factors, including the age of the individual and the
degree of exertion.
Braille
A system of raised-dot writing for the
blind in which each letter is represented as a raised
pattern that can be read by touching it with the fin-
gers. In Braille, dot patterns are assigned to letters
of the alphabet, punctuation marks, and other sym-
bols. Braille was devised by Louis Braille.
brain
The portion of the central nervous system
that is located within the skull. It functions as a pri-
mary receiver, organizer, and distributor of infor-
mation for the body. It has a right half and a left half,
each of which is called a hemisphere.
brain, fornix of the
One of a pair of arching
fibrous bands in the brain that connects the two
lobes of the cerebrum.
brain, water on the
See 
hydrocephalus.
brain aneurysm
See 
aneurysm, brain.
brain cancer
A malignant growth of the brain.
See also 
brain tumor.
brain death
The permanent, irreversible cessa-
tion of all brain functions. Brain death is not the
same thing as a coma or vegetative state. The pres-
ence of brain death is legally synonymous with death
itself in most US states.
brain freeze
A headache that occurs when one
puts ice, a cold food, or a chilled beverage in the
mouth, chilling the roof of the mouth. Ice cream is
by far the most frequent offender. Brain freeze is
characterized by a stabbing, aching pain that begins
a few seconds after ingestion of something cold. The
pain peaks in 30 to 60 seconds. No treatment is
required. Also known as an ice cream headache.