Webster's New World Medical Dictionary

pathobiology
The biology of disease.
pathogen
An agent of disease. For example,
Bacillus anthracis is the pathogen that causes anthrax.
pathogenesis
The development of a disease and
the chain of events leading to that disease.
pathogenetic
Pertaining to genetic cause of a dis-
ease or condition. For example, BRCA 1 and BRCA2
are genes that, when mutated, are responsible for
many cases of cancer of the breast. Therefore, these
genes are pathogenetic.
pathogenic
Capable of causing disease. For
example, pathogenic E. coli are Eschericia coli bac-
teria that can make a person ill.
pathognomonic
A sign or symptom that is so
characteristic of a disease that it can be used to
make a diagnosis. For example, Koplik spots in the
mouth opposite the first and second upper molars
are pathognomonic of measles.
pathologist
A physician who identifies diseases
and conditions by studying abnormal cells and
tissues.
pathology 1
The study of disease.
2
Incorrectly
(but commonly), disease. For example, “The physi-
cian found no pathology” would mean the physician
found no evidence of disease.
pathophysiology
Deranged function in an indi-
vidual or an organ due to a disease. For example, a
pathophysiologic alteration is a change in function
as distinguished from a structural defect.
-
pathy
Suffix indicating suffering or disease, as in
neuropathy (disease of the nervous system).
Pavlovian conditioning
A method to cause a
reflex response or behavior by training with repeti-
tive action. The Russian physiologist Ivan Petrovich
Pavlov conditioned dogs to respond in what proved
to be a predictable manner. For example, when he
customarily rang a bell before feeding them, the dogs
would begin to salivate whenever the bell rang. The
principles of Pavlovian conditioning form the basis
of much modern behavioral science.