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Medical Dictionary - Dictionary of Medicine and Human Biology


Medical Dictionary


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phonocardiogram (fo-no-kar′de-o-gram)
A record of the heart sounds made by means of a phonocardiograph.

phonocardiograph (fo-no-kar′de-o-graf)
An instrument, utilizing microphones, amplifiers, and filters, for graphically recording the heart sounds, which are displayed on an oscilloscope or analog tracing. linear p. a p. that records all chest wall vibrations resulting from cardiac activity, with emphasis on low-frequency vibrations due to its filter characteristics. logarithmic p. a p. that records only theoretically audible vibrations with emphasis on the higher frequencies due to filter characteristics designed to imitate the logarithmic frequency-intensity response of the human auditory apparatus. spectral p. an instrument for recording the heart sounds in which the electrical changes created by the latter pass from a microphone through a series of filters, each of which is tuned to a particular frequency band; output from each filter activates a separate light source of brightness proportional to the intensity of the sound transmitted through that filter; the lights are arranged vertically in descending order of frequencies. A record is obtained by photographing the vertical row of lights. stethoscopic p. a p. that records all sound vibrations, audible and inaudible, conveyed by the stethoscope; however, very low-frequency vibrations (in the range of body movements) are filtered out.

phonocardiography (fo′no-kar-de-og′ra-fe)
1. Recording of the heart sounds with a phonocardiograph. 2. The science of interpreting phonocardiograms. [phono- + G. kardia, heart, + grapho, to record]

phonocatheter (fo-no-kath′e-ter)
A cardiac catheter with diminutive microphone in its tip, for recording sounds and murmurs from within the heart and great vessels.

phonogram (fo′no-gram)
A graphic curve depicting the duration and intensity of a sound. [phono- + G. gramma, diagram]

phonology (fo-nol′o-je)
SYN: phonetics. [phono- + G. logos, study]

phonomania (fo-no-ma′ne-a)
Rarely used term for a homicidal mania. [G. phonos, murder, + mania, frenzy]

phonometer (fo-nom′e-ter)
An instrument for measuring the frequency and intensity of sounds. [phono- + G. metron, measure]

phonomyoclonus (fo′no-mi-ok′lo-nus)
Clonic spasms of muscles in response to aural stimuli. [phono- + G. mys, muscle, + klonos, tumult]

phonomyography (fo′no-mi-og′ra-fe)
The recording of the varying sounds made by contracting muscular tissue. [phono- + G. mys, muscle, + graphe, drawing]

phonopathy (fo-nop′a-the)
Any disease of the vocal system affecting speech. [phono- + G. pathos, suffering]

phonophobia (fo-no-fo′be-a)
Morbid fear of one's own voice, or of any sound. [phono- + G. phobos, fear]

phonophore (fo′no-for)
A form of binaural stethoscope with a bell-shaped chest piece into which project the recurved extremities of the sound tubes. [phono- + G. phoros, carrying]

phonophotography (fo′no-fo-tog′ra-fe)
The recording on a moving photographic plate of the movements imparted to a diaphragm by sound waves. [phono- + photography]

phonopsia (fo-nop′se-a)
A condition in which the hearing of certain sounds gives rise to a subjective sensation of color. [phono- + G. opsis, vision]

phonoreceptor (fo′no-re-sep′ter)
A receptor for sound stimuli.

phonoscope (fo′no-skop)
Obsolete term for an instrument for recording ausculatory percussion; originally used for photographic recording of heart sounds. [phono- + G. skopeo, to view]

phonoscopy (fo-nos′ko-pe)
The recording made by a phonoscope.

phonosurgery (fo′no-ser′jer-e)
A group of operations designed to improve or alter the voice.

phor-
See phoro-.

phorbin (for′bin)
The parent hydrocarbon of chlorophyll; differs from porphin (porphyrin) in the presence of an isocyclic ring formed by the addition of a two-carbon group bridging the 13 and 15 positions of porphin (porphyrin) and by saturation of the 17–18 double bond (with realignment of conjugated double bonds). Addition of hydrocarbon side chains in specific locations yields phorbins characterized by prefixes; e.g., phenophorbin.

phorbol (for′bol)
The parent alcohol of the cocarcinogens, which are 12,13(9,9a) diesters of p. found in croton oil; the hydrocarbon skeleton is a cyclopropabenzazulene; p. esters mimic 1,2-diacylglycerol as activators of protein kinase C.

phoresis (for′e-sis, fo-re′sis)
1. SYN: electrophoresis. 2. A biologic association in which one organism is transported by another, as in the attachment of the eggs of Dermatobia hominis, a human and cattle botfly, to the legs of a mosquito, which transports them to the human, cattle, or other host in which the botfly larvae can develop. SYN: epizoic commensalism, phoresy. [G. p., a being borne]

phoresy (for′e-se)
SYN: phoresis (2) .

phoria (for′e-a)
The relative directions assumed by the eyes during binocular fixation of a given object in the absence of an adequate fusion stimulus. See cyclophoria, esophoria, exophoria, heterophoria, hyperphoria, hypophoria, orthophoria. [G. phora, a carrying, motion]

Phormia regina (for′me-a re-ji′na)
The black blowfly, the larvae of which were formerly used in the treatment of septic wounds because they secrete a proteolytic enzyme that aids in the removal of dead tissue; it is a frequent cause of maggot infestation of sheep, depositing eggs in the wool, and is a widely distributed cold weather species that lays its eggs on dead or decaying tissues.

phoro-, phor-
Carrying, bearing; a carrier, a bearer; phobia. [G. phoros, carrying, bearing]

Phoroptor (fo-rop′ter)
A device containing different lenses that is used for refraction of the eye.

phorozoon (for-o-zo′on)
The nonsexual stage in the life history of an animal that passes through several phases in its life cycle. [phoro- + G. zoon, animal]

phos-
Light. [G. phos]

phosgene (CG) (fos′jen)
Carbonyl chloride;a colorless liquid below 8.2°C, but an extremely poisonous gas at ordinary temperatures; it is an insidious gas, since it is not immediately irritating, even when fatal concentrations are inhaled; more than 80% of World War I chemical agent fatalities were caused by p.. p. oxime (CX) a blister agent stored by the military of some governments; a powerful irritant that produces immediate pain. SYN: dichloroformoxime.

phosph-, phospho-, phosphor-, phosphoro-
Prefixes indicating the presence of phosphorus in a compound.See phospho- for specific usage of that prefix. [G. phos, light; phoros, carrying]

phosphagen (fos′fa-jen)
Energy-rich guanidinium or amidine phosphate, serving as an energy store in muscle and brain; e.g., phosphocreatine in mammals, phosphoarginine in invertebrates. Other phosphagens include phosphoagmatine, phosphoglycocyamine, and phospholombricine.

phosphagenic (fos-fa-jen′ik)
Phosphate-producing.

phosphamic acid (fos-fam′ik)
R–NH–PO3H2, one of the three types of high-energy phosphates (the others being phosphophosphoric acids and phosphosulfuric acids).

phosphamidase (fos-fam′i-das)
SYN: phosphoamidase.

phosphastat (fos′fa-stat)
A conceptual mechanism whereby the parathyroid hormone is increased when the levels of phosphorus rise to an above-normal level; there is as yet no satisfactory evidence for its existence. [phosphate + L. status, a standing]

phosphatase (fos′fa-tas)
Any of a group of enzymes (EC 3.1.3.x) that liberate orthophosphate from phosphoric esters. SEE ALSO: phosphohydrolases. acid p. a p. with an optimum pH of less than 7.0 (for several isozymes, it is 5.4), notably present in the prostate gland; demonstrable in lysosomes with Gomori nonspecific acid p. stain; it hydrolyzes many orthophosphoric monoesters. alkaline p. a p. with an optimum pH of above 7.0 ( e.g., 8.6), present ubiquitously; localized cytochemically in membranes by modifications of Gomori nonspecific alkaline p. stain; it hydrolyzes many orthophosphoric monoesters; low levels of this enzyme are seen in cases of hypophosphatasia.

phosphate (fos′fat)
1. A salt or ester of phosphoric acid. For individual phosphates not listed here, see under the name of the base. 2. The trivalent ion, PO43−. bone p. SYN: tribasic calcium p.. codeine p. a water-soluble salt of codeine often used in the pharmaceutical preparation of codeine-containing liquid medications. cyclic p. SYN: adenosine 3′,5′-cyclic monophosphate. dihydrogen p. one-third-neutralized phosphoric acid; e.g., NaH2PO4, KH2PO4. disodium p. na2HPO4. energy-rich phosphates SYN: high-energy phosphates. high-energy phosphates those p. esters and phosphoanhydrides that, on hydrolysis, yield an unusually large amount of energy; e.g., nucleotide polyphosphates such as ATP, enol phosphates such as phosphoenolpyruvate. SEE ALSO: high-energy compounds, under compound. SYN: energy-rich phosphates. inorganic p. (Pi) SYN: inorganic orthophosphate. monopotassium p. KH2PO4;a dihydrogen p. used as a reagent; commonly used in buffers. monosodium p. NaH2PO4;a dihydrogen p. used as a reagent; commonly used in buffers. normal p. a salt of phosphoric acid or pyrophosphoric acid in which all the hydrogen atoms are displaced; e.g., Na3PO4, Na4P2O7. organic p. an ester of phosphoric acid; e.g., glycerol p., adenosine p., hexose p.. triple p. 1. magnesium ammonium p., MgNH4PO4; 2. a crude p. fertilizer product from p. rock and phosphoric acid. trisodium p. Na3PO4;used to emulsify fats, oil, and grease; an irritant.

phosphate acetyltransferase
An enzyme-catalyzing transfer of an acetyl moiety from acetyl-CoA to orthophosphate, forming acetyl phosphate and coenzyme A. SYN: phosphoacylase, phosphotransacetylase.

phosphated (fos′fat-ed)
Containing phosphates.

phosphatemia (fos-fa-te′me-a)
An abnormally high concentration of inorganic phosphates in the blood. [phosphate + G. haima, blood]

phosphatic (fos-fat′ik)
Relating to or containing phosphates.

phosphatidal (fos-fa-ti′dal)
Older trivial name for alk-1-enylglycerophospholipid; plasmenyl.

phosphatidase (fos-fa-ti′das)
SYN: phospholipase A2.

phosphatidate (fos-fa-ti′dat)
A salt or ester of a phosphatidic acid. p. phosphatase an enzyme that catalyzes the hydrolysis of p. producing orthophosphate and 1,2-diacylglycerol; this enzyme participates in phospholipid and triacylglycerol metabolism.

phosphatide (fos′fa-tid)
Former name for 1) phosphatidic acid and 2) phosphatidate.

phosphatidic acid (fos′fa-tid′ik)
1,2-Diacylglycerol phosphate;a derivative of glycerophosphoric acid in which the two remaining hydroxyl groups of the glycerol are esterified with fatty acids; e.g., phosphatidic acids attached to choline are phosphatidylcholines (lecithins).

phosphatidolipase (fos′fa-ti-do-lip′as)
SYN: phospholipase A2.

phosphatidyl (Ptd) (fos-fa-ti′dil)
The radical of a phosphatidic acid; e.g., phosphatidylcholine.

phosphatidylcholine (PtdCho) (fos-fa-ti′dil-ko′len)
See lecithin.

phosphatidylethanolamine (PtdEth) (fos-fa-ti′dil-eth-a-nol′a-men)
The condensation product of a phosphatidic acid and ethanolamine; found in biomembranes. SEE ALSO: cephalin. p. cytidylyltransferase a key enzyme in the biosynthesis of cephalin; it catalyzes the reaction of phosphoethanolamine and CTP to form CDP-ethanolamine and pyrophosphate.

phosphatidylglycerol (fos-fa-ti′dil-glis′er-ol)
A phosphatidic acid in which a second glycerol molecule replaces the usual choline, or ethanolamine or serine; a constituent in human amniotic fluid that denotes fetal lung maturity when present in the last trimester.

phosphatidylinositol (PtdIns) (fos-fa-ti′dil-in-o′si-tol)
A phosphatidic acid combined with inositol found in biomembranes and a precursor to certain cellular signals. Sometimes referred to as inositide. SYN: phosphoinositide. p. 4,5-bisphosphate (PIP2, PtdIns(4,5)P2) p. with two additional sites of phosphorylation; an important constituent of cell membrane phospholipids as well as a precursor of the second messengers, diacylglycerol and inositol 1,4,5-trisphosphate. p. 4-phosphate the intermediate in the biosynthesis of p. 4,5-bisphosphate from p.. p. synthase an enzyme that catalyzes the reaction of CDP-diacylglycerol with inositol to form CMP and p.; found in the endoplasmic reticulum.

phosphatidylserine (PtdSer) (fos-fa-ti′dil-ser′en)
The condensation product of phosphatidic acid and serine; found in biomembranes. SEE ALSO: cephalin.

phosphaturia (fos-fa-too′re-a)
Excessive excretion of phosphates in the urine. SYN: phosphoruria, phosphuria. [phosphate + G. ouron, urine]

phosphene (fos′fen)
Sensation of light produced by mechanical or electrical stimulation of the peripheral or central optic pathway of the nervous system. [G. phos, light, + phaino, to show] accommodation p. a p. occurring during accommodation, caused by sudden relaxation of the ciliary muscle.

phosphide (fos′fid)
A compound of phosphorus with valence −3; e.g., sodium p., Na3P.

phosphine (fos′fen, -fin)
A colorless poisonous war gas with a characteristic garlic-like odor; also the active agent in some rodenticides; formed in small quantities in the putrefaction of organic matter containing phosphorus. SYN: hydrogen phosphide, phosphureted hydrogen.

phosphinico-
In chemistry, symmetrically doubly substituted phosphinic acid, R2P(O)OH.

phosphite (fos′fit)
A salt of phosphorous acid.

phospho-
Prefix for O-phosphono-, which may replace the suffix phosphate; e.g., glucose phosphate is O-phosphonoglucose or phosphoglucose. SEE ALSO: phosph-, phosphoryl-.

phosphoacylase (fos-fo-as′i-las)
SYN: phosphate acetyltransferase.

3′-phosphoadenosine 5′-phosphate (PAP) (fos′fo-a-den′o-sen)
A product in sulfuryl transfer reactions.

3′-phosphoadenosine 5′-phosphosulfate (PAPS)
See adenosine 3′-phosphate 5′-phosphosulfate.

phosphoamidase (fos-fo-am′i-das)
An enzyme catalyzing the hydrolysis of phosphorus-nitrogen bonds, notably the hydrolysis of N-phosphocreatine to creatine and orthophosphate. SYN: phosphamidase.

phosphoamides (fos-fo-am′idz)
Amides of phosphoric acid (phosphoramidic acids) and their salts or esters (phosphoramidates), of the general formula (HO)2P(O)–NH2; e.g., creatine phosphate.

phosphoarginine (fos-fo-ar′gi-nen)
A compound (in particular, a phosphagen) of l-arginine with phosphoric acid containing the phosphoamide bond; a source of energy in the contraction of muscle in invertebrates, corresponding to phosphocreatine in the muscles of vertebrates. Cf.:phosphocreatine. SYN: arginine phosphate.

phosphocholine (fos-fo-ko′len)
Choline O-phosphate;important in choline metabolism, e.g., in the biosynthesis of lecithins. SYN: phosphorylcholine. p. cytidylyltransferase an enzyme that catalyzes the reaction of p. with CTP to form pyrophosphate and CDP-choline; the rate-limiting step of lecithin biosynthesis; the cytosolic form of the enzyme is inactive (a phosphorylated form of the enzyme). p. diacylglycerol transferase an enzyme in lecithin biosynthesis that catalyzes the reaction of 1,2-diacylglycerol with CDP-choline to form CMP and phosphatidylcholine.




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