English dictionary of medical terms (68)
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- No:1340 - photosensitivity
(photo- + sensitivity) an abnormal cutaneous response involving the
interaction between photosensitizing substances and sunlight or
filtered or artificial light at wavelengths of 280-400 mm. There
are two main types : photoallergy and photoxicity.
- No:1341 - photosensitization
the development of abnormally heightened reactivity of the skin to
- No:1342 - physical
pertaining to the body, to material things, or to physics.
- No:1343 - physicochemical
pertaining to physics and chemistry.
- No:1344 - physiologic
normal; not pathologic; characteristic of or conforming to the
normal functioning or state of the body or a tissue or organ;
- No:1345 - pigmentation
1. the deposition of colouring matter; the coloration or
discoloration of a part by pigment. 2. coloration, especially
abnormally increased coloration, by melanin.
- No:1346 - piloerection
(pilo- + erection) erection of the hair.
- No:1347 - pityriasis
(Gr. pityron bran + -iasis) a name originally applied to a group of
skin diseases characterized by the formation of fine, branny
scales, but now used only with a modifier.
- No:1348 - placebo
(L. 'I will please') any dummy medical treatment; originally, a
medicinal preparation having no specific pharmacological activity
against the patient's illness or complaint given solely for the
psychophysiological effects of the treatment; more recently, a
dummy treatment administered to the control group in a controlled
clinical trial in order that the specific and nonspecific effects
of the experimental treatment can be distinguished - i.e., the
experimental treatment must produce better results than the placebo
in order to be considered effective.
- No:1349 - placenta
- (L. 'a flat cake') an organ characteristic of true mammals during
pregnancy, joining mother and offspring, providing endocrine
secretion and selective exchange of soluble, but not particulate,
blood-borne substances through an apposition of uterine and
trophoblastic vascularized parts. According to species, the area of
vascular apposition may be diffuse, cotyledonary, zonary or
discoid; the nature of apposition may be labyrinthine or villous;
the intimacy of apposition may vary according to what layers are
lost of those originally interposed between maternal and fetal
blood (maternal endothelium, uterine connective tissue, uterine
epithelium, chorion, extraembryonic mesoderm, and endothelium of
villous capillary). The chorion may be joined by and receive blood
vessels from either the yolk sac or the allantois, and the uterine
lining may be largely shed with the chorion at birth (deciduate) or
may separate from the chorion and remain (nondeciduate). The human
placenta is discoid, villous, haemochorial, chorioallantoic, and
deciduate. After birth, it weighs about 600 gm. and is about 16
cm. in diameter and 2 cm. thick, discounting a principal functional
part, the maternal blood in the intervillous space (which leaks out
at birth) into which the chorionic villi dip. The villi are
grouped into adjoining cotyledons making about 20 velvety bumps on
the side of the placenta facing outward to the uterus; the inner
side of the placenta facing the fetus is smooth, being covered with
amnion, a thin avascular layer that continues past the edges of the
placenta to line the entire hollow sphere of chorion except where
it is reflected to cover the umbilical cord, which joins fetus and
placenta. The cord usually joins the placenta near the centre but
may insert at the edge, on the nonplacental chorion, or on an
- No:1350 - plasma expander
artificial plasma extender.
- No:1351 - plasma protein
one of the hundreds of different proteins present in blood plasma,
including carrier proteins ( such albumin, transferrin, and
haptoglobin), fibrinogen and other coagulation factors, complement
components, immunoglobulins, enzyme inhibitors, precursors of
substances such as angiotension and bradykinin, and many other
types of proteins.
- No:1352 - plasminogen
the inactive precursor of plasmin (=enzyme that catalyses the
hydrolysis of peptide bonds at the carbonyl end of lysine or
- No:1353 - pleurisy
(Gr. pleuritis) inflammation of the pleura, with exudation into its
cavity and upon its surface. It may occur as either an acute or a
chronic process. In acute pleurisy the pleura becomes reddened,
then covered with an exudate of lymph, fibrin, and cellular
elements (the dry stage); the disease may progress to the second
stage, in which a copious exudation of serum occurs (stage of
liquid effusion). The inflamed surfaces of the pleura tend to
become united by adhesions, which are usually permanent. The
symptoms are a stitch in the side, a chill, followed by fever and
a dry cough. As effusion occurs there is an onset of dyspnea and
a diminution of pain. The patient lies on the affected side.
- No:1354 - plexus
(L. 'braid) a network or tangle; (NA) a general term for a network
of lymphatic vessels, nerves, or veins.
- No:1355 - pneumonia
(Gr. pneumonia) inflammation of the lungs with consolidation.
- No:1356 - pneumonopath
(pneumono- + Gr. pathos disease) any disease of the lung.
- No:1357 - poliomyelitis
(polio- + Gr. myelos marrow + -itis) an acute viral disease,
occurring sporadically and in epidemics, and characterized
clinically by fever, sore throat, headache, and vomiting, often
with stiffness of the neck and back. In the minor illness these
may be the only symptoms. The major illness, which may or may not
be preceded by the minor illness, is characterized by involvement
of the central nervous system, stiff neck, pleocytosis in the
spinal fluid, and perhaps paralysis. There may be subsequent
atrophy of groups of muscles, ending in contraction and permanent
deformity. The major illness is called acute anterior p.,
infantile paralysis and Heine-Medin disease. The disease is now
largely controlled by vaccines.
- No:1358 - polyarthritis
(poly- + Gr. arthron joint + -itis) an inflammation of several
- No:1359 - polydipsia
(poly- + Gr. dipsa thirst + -ia) chronic excessive thirst, as in
diabetes mellitus or diabetes insipidus.
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