Author: Glossary

  • Photoreceptor

    Nerve endings capable of being stimulated by light, such as the rods and cones of the retina. Light strikes the photoreceptor (rods and cones), leading to a structural change in a chemical pigment that activates an enzyme. The net effect is that the movement of sodium is altered, leading to a nerve signal that is…

  • Phenylephrine

    Drug that constricts blood vessels, raising blood pressure; dilates the pupils of the eyes, and relieves nasal congestion. It is given by injection to raise blood pressure and is combined with other drugs in many nasal sprays and eyedrop preparations to relieve symptoms of allergy and the common cold (e.g., runny nose). A drug that…

  • Phensuximide

    Anticonvulsant used to treat petit mal. Adverse effects include gastrointestinal upset, drowsiness and other signs of central nervous system depression, and blood abnormalities. An anticonvulsant drug used to prevent or reduce petit mal fits in epilepsy. It is administered by mouth; side-effects may include dizziness, drowsiness, nausea, and loss of appetite.  

  • Phenolphthalein

    Laxative, found in many preparations under a variety of trade names. Adverse effects include abdominal cramps and possible allergic reactions. An irritant laxative administered by mouth, usually given at night to act the following morning. Side-effects may include stomach cramps.  

  • Pheniramine

    Antihistamine, found in many preparations for allergies and respiratory infections, used to treat rhinitis, skin rashes, and pruritis. Adverse effects include sedation, dry mouth, and rapid heart rate. An antihistamine used to treat allergic reactions such as hay fever and urticaria. It is administered by mouth or is applied to the skin in an ointment;…

  • Phallic phase

    In psychoanalytic theory, the third stage in a person’s development, usually between the ages of 3 and 6, when awareness and/or self-manipulation of the genitals is a prime source of pleasure.  

  • Pestilence

    General term for affliction, ailment; historically, refers to the fatal epidemic disease bubonic plague transmitted by the bite of an infected rat flea. A fatal epidemic disease, like the plague.  

  • Pesticide poisoning

    Toxic condition brought on by ingestion or inhalation of a pesticide. A chemical injury caused by exposure to substances intended to kill insects or vermin. Pesticide poisoning can occur in people who handle or are otherwise exposed to the chemicals used to kill insects. Exposure to pesticides can involve the skin, particularly of those who…

  • Peroneus

    Either of two (peroneus brevis and peroneus longus) muscles of the lower leg, involved in movement of the foot. Relating to or supplying the outer (fibular) side of the leg. One of three muscles of the leg that act to move the foot.  

  • Permanent tooth

    Any of the set of 32 teeth that appear during and after childhood and, in the optimal case, last until old age. In each jaw there are 4 incisors, 2 canines, 4 premolars, and 6 molars. They replace the 20 deciduous (milk) teeth of early childhood, usually starting to erupt in the 6th year and…