Category: P
-
Pica
A feeding and eating disorder of infancy or early childhood characterized by developmentally inappropriate, persistent, or recurring eating of nonnutritive substances (e.g., dirt). An unnatural desire for foods; alternative words are cissa, cittosis, and allotriophagy. Also a perverted appetite (eating of earth, sand, clay, paper, etc.). An eating disorder consisting of the craving and eating…
-
Piblokto
Observed primarily among Eskimo communities, piblokto is an abrupt dissociative episode accompanied by extreme excitement of up to 30 minutes’ duration and frequently followed by convulsive seizures and coma lasting up to 12 hours. Also referred to as arctic hysteria. A syndrome, apparently culturally specific for Eskimo women, in which the person screams, removes or…
-
Pia mater
The innermost of the meninges; a delicate fibrous membrane closely enveloping the brain and spinal cord. The innermost and most delicate of the three membranes covering the brain and spinal cord. Innermost of the three meninges covering the brain and spinal cord (the other two being the dura mater and arachnoid); it is highly vascular…
-
Phrenology
A discredited theory positing a relationship between the structure of the skull and mental traits. A pseudoscience based on the belief that the contours or bumps of the skull are indicative of a person’s personality, character, and mental facilities. The study of the bumps on the outside of the skull in order to determine a…
-
Photophobia
Abnormal intolerance to light, often associated with albinism, drug-induced pupil dilation, migraine, encephalitis, measles, and other diseases. Abnormal sensitivity to, and intolerance of, light. Photophobia can be a symptom of a variety of diseases and conditions, such as excessive wear of contact lenses, eye injury or infection, inflammation, migraine headache, meningitis (inflammation of the brain…
-
Phonophobia
The fear of or increased sensitivity to loud noises. A fear of loud noises. A morbid fear of sound or noise. A fear of talking or an intense aversion to sound.
-
Phobia
Fear cued by the presence or anticipation of a specific object or situation, exposure to which almost invariably provokes an immediate anxiety response or panic attack even though the subject recognizes that the fear is excessive or unreasonable. The phobic stimulus is avoided or endured with marked distress. Two types of phobia have been differentiated:…
-
Phenylketonuria (PKU)
A genetic metabolic disturbance characterized by an inability to convert phenylalanine to tyrosine. It is treatable by diet when detected in early infancy; if untreated, intellectual disability results. Also known as phenylpyruvic oligophrenia. A genetic disease caused by a recessive gene that results in an infant being unable to metabolize phenylalanine, an essential amino acid…
-
Phenothiazines
Subgroup of conventional antipsychotic drugs that, chemically, have in common a phenothiazine configuration (i.e., phenyl rings and heterocyclic ring containing nitrogen and sulfur) but differ from one another through variations in side chains. Based on the side chain attached to the nitrogen atom in the middle ring, the phenothiazines are subdivided into three subgroups: aliphatic…
-
Phenomenology
The study of occurrences or happenings in their own right rather than from the point of view of inferred causes; specifically, the theory that behavior is determined not by external reality as it can be described objectively in physical terms but rather by the way in which the subject perceives that reality at any moment.…