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Medical Dictionary - Dictionary of Medicine and Human Biology

Medical Dictionary


aphasiac, aphasic (a-fa′ze-ak, a-fa′sik)
Relating to or suffering from aphasia.

aphasiologist (a-fa′ze-ol′o-gist)
A specialist who deals with speech disorders caused by dysfunction of the language areas of the brain.

aphasiology (a-fa′ze-ol′o-ge)
The science of speech disorders caused by dysfunction of the cerebral language areas.

aphasmid (a-faz′mid)
1. Lacking phasmids, as seen in nematodes of the class Adenophorasida (Aphasmidia). 2. Common name for a member of the class Aphasmidia, now Adenophorasida.

Aphasmidia (a-faz-mid′e-a)
SYN: Adenophorasida.

apheliotropism (ap-he-le-ot′ro-pizm)
Negative heliotaxis. [G. apo, away, + helios, sun, + tropein, to turn]

apheresis (a-fer-e′sis)
Infusion of a patient's own blood from which certain cellular or fluid elements (plasma, leukocytes, platelets, etc.) have been removed. [G. aphairesis, withdrawal]

aphilopony (a-fil-op′o-ne)
Obsolete term for an aversion, or lack of desire, to work. [G. a- priv. + philo, to like, + ponos, work]

aphonia (a-fo′ne-a)
Loss of the voice as a result of disease or injury to the larynx. [G. a- priv. + phone, voice] hysterical a. loss of voice for psychogenic reasons, as in some varieties of hysteria. SYN: nonorganic a.. nonorganic a. SYN: hysterical a.. a. paralytica a. due to paralysis of the vocal cords. spastic a. a. caused by spasmodic contraction of the laryngeal adductor muscles provoked by attempted phonation.

aphonic (a-fon′ik)
Relating to aphonia. SYN: aphonous.

aphonous (af′o-nus)
SYN: aphonic.

aphotesthesia (a-fo-tes-the′ze-a)
Decreased sensitivity of the retina to light caused by excessive exposure to sunlight. [G. a- priv. + phos, light, + aisthesis, perception]

aphrasia (a-fra′ze-a)
Inability to speak, from any cause. [G. a- priv. + phrasis, speaking]

aphrodisia (af-ro-diz′e-a)
Sexual desire, especially when excessive. [G. aphrodisios, relating to Aphrodite]

aphrodisiac (af-ro-diz′e-ak)
1. Increasing sexual desire. 2. Anything that arouses or increases sexual desire.

aphrodisiomania (af-ro-diz′e-o-ma′ne-a)
Abnormal and excessive erotic interest. [G. aphrodisia, sexual pleasures, + mania, insanity]

aphtha, pl .aphthae (af′tha, af′the)
1. In the singular, a small ulcer on a mucous membrane. 2. In the plural, stomatitis charactized by intermittent episodes of painful oral ulcers of unknown etiology that are covered by gray exudate, are surrounded by an erythematous halo, and range from several millimeters to 2 cm in diameter; they are limited to oral mucous membranes that are not bound to periosteum, occur as solitary or multiple lesions, and heal spontaneously in 1–2 weeks. SYN: aphthae minor, aphthous stomatitis, canker sores, recurrent aphthous stomatitis, recurrent aphthous ulcers, recurrent ulcerative stomatitis, ulcerative stomatitis. [G. ulceration] Bednar aphthae traumatic ulcers located bilaterally on either side of the midpalatal raphe in infants. herpetiform aphthae a variant of oral aphthae, of unknown etiology, characterized by up to several dozen ulcers, 2–3 mm in diameter, organized in a clustered herpetiform distribution. aphthae major a severe form of aphthae characterized by unusually numerous, large, deep, and frequent ulcers; healing may take as long as 6 weeks and results in scarring. SYN: Mikulicz aphthae, periadenitis mucosa necrotica recurrens, recurrent scarring aphthae, Sutton disease. Mikulicz aphthae SYN: aphthae major. aphthae minor SYN: a. (2) . recurrent scarring aphthae SYN: aphthae major.

aphthoid (af′thoyd)
Resembling aphthae.

aphthosis (af-tho′sis)
Any condition characterized by the presence of aphthae.

aphthous (af′thus)
Characterized by or relating to aphthae or aphthosis.

Aphthovirus (af′tho-vi′rus)
A genus in the family Picornaviridae associated with foot and mouth disease of cattle.

aphylactic (a-fi-lak′tik)
Obsolete term for pertaining to or characterized by aphylaxis.

aphylaxis (a-fi-lak′sis)
Obsolete term for lack of protection against disease. SYN: nonimmunity. [G. a- priv. + phylaxis, a guarding]

apical (ap′i-kal) [TA]
1. Relating to the apex or tip of a pyramidal or pointed structure. 2. Situated nearer to the apex of a structure in relation to a specific reference point; opposite of basal. SYN: apicalis [TA] .

apicalis (ap-i-ka′lis) [TA]
SYN: apical, apical. [L.]

apicectomy (ap-i-sek′to-me)
1. Opening and exenteration of air cells in the apex of the petrous part of the temporal bone. 2. In dental surgery, an obsolete synonym for apicoectomy. [L. apex, summit or tip, + G. ektome, excision]

apiceotomy (a-pis-e-ot′o-me)
SYN: apicotomy.

apices (ap′i-ses)
Plural of apex.

An apex; apical [L. apex, apicis, a summit or a tip + -o-]

apicoectomy (ap′i-ko-ek′to-me)
Surgical removal of a tooth root apex. SYN: root resection. [apico- + G. ektome, tooth excision]

apicolocator (ap′i-ko-lo′ka-tor)
A device for locating the root apex of a tooth.

apicolysis (ap-i-kol′i-sis)
Surgical collapse of the upper portion of the lung by the operative detachment of the parietal pleura allowing inferomedial displacement of the pulmonary apex. [apico- + G. lysis, destruction]

Apicomplexa (ap-i-kom-plek′sa)
A phylum of the subkingdom Protozoa, which includes the class Sporozoea and the subclasses Coccidia and Piroplasmia, and is characterized by the presence of an apical complex. [L. apex, pl. apicis, tip, summit, + complexus, woven together]

apicostome (ap′i-ko-stom)
The trocar and cannula used in apicostomy.

apicostomy (ap-i-kos′to-me)
An operation in which the labial or buccal alveolar plate is perforated with a trocar and cannula; done to reach the root apex and to take bacterial cultures from this area. [apico- + G. stoma, mouth]

apicotomy (ap-i-kot′o-me)
Incision into an apical structure. SYN: apiceotomy. [apico- + G. tome, a cutting]

apiculate (a-pik′u-lat)
Terminated abruptly by a small point. [L. apiculus, a tip or point]

apiculus (a-pik′u-lus)
A short, sharp projection on one end of a fungus spore at the point of attachment, or on the wall, of a hypha or condiophore. [L.]

apicurettage (ap-i-ku′re-tahzh)
Apical curettage after removal of an infected tooth.

apinealism (a-pin′e-al-izm)
Acquired absence of the pineal gland.

apiphobia (a-pi-fo′be-a)
Morbid fear of bees. SYN: melissophobia. [L. apis, bee, + G. phobos, fear]

apituitarism (a-pi-too′i-tar-izm)
Total lack of functional pituitary tissue; may be iatrogenic ( e.g., as a consequence of hypophysectomy) or the result of a spontaneous disease process.

aplacental (a-pla-sen′tal)
Without a placenta; denoting the monotremes (which lay eggs and have no placenta) and the marsupials (which have a transitory simple yolk-sac placenta).

aplanatic (ap-la-nat′ik)
Pertaining to aplanatism, or to an a. lens.

aplanatism (a-plan′a-tizm)
Freedom from spherical aberration; said of a lens. [G. a- priv. + planetos, wandering]

aplasia (a-pla′ze-a)
1. Defective development or congenital absence of an organ or tissue. 2. In hematology, incomplete, retarded, or defective development, or cessation of the usual regenerative process. [G. a- priv. + plasis, a molding] congenital a. of thymus SYN: DiGeorge syndrome. a. cutis congenita [MIM*107600, *207700, *207730] congenital absence or deficiency of a localized area of skin, with the base of the defect covered by a thin translucent membrane; most often a single area near the vertex of the scalp, but may occur in other areas; underlying structures may also be affected; autosomal inheritance, either dominant or recessive. germinal a. SYN: seminiferous tubule dysgenesis. gonadal a. congenital absence of essentially all gonadal tissue; the external genitalia and genital ducts are female, but if interstitial cells of Leydig are present, the external genitalia are commonly ambiguous and the genital ducts are female. SEE ALSO: gonadal dysgenesis, gonadal agenesis. Cf.:Klinefelter syndrome, Turner syndrome. pure red cell a. a transitory arrest of red blood cell production which may occur in the course of a hemolytic anemia, often preceded by infection, or as a complication of certain drugs; if the arrest persists, severe anemia may result. SEE ALSO: congenital hypoplastic anemia.

aplastic (a-plas′tik, a-)
Pertaining to aplasia, or conditions characterized by defective regeneration, as in a. anemia.

apleuria (a-ploor′e-a)
Congenital absence of one or more ribs; usually associated with absent transverse process or processes. [a- priv. + G. pleura, rib]

apnea (ap′ne-a)
Absence of breathing. [G. apnoia, want of breath] central a. a. as the result of medullary depression which inhibits respiratory movement. deglutition a. inhibition of breathing during swallowing. induced a. intentional respiratory arrest during general anesthesia produced by hypocapnia, a muscle relaxant drug, respiratory center depression, or sudden cessation of controlled respiration. obstructive sleep a. a disorder, first described in 1965, characterized by recurrent interruptions of breathing during sleep due to temporary obstruction of the airway by lax, excessively bulky, or malformed pharyngeal tissues (soft palate, uvula, and sometimes tonsils), with resultant hypoxemia and chronic lethargy.Symptoms of obstructive sleep a. are loud snoring, recurrent apneic episodes during sleep followed by gasping inspiration with partial or complete arousal, nocturnal restlessness, and daytime sleepiness. Apneic episodes last 10–120 seconds and may be accompanied by sinus bradycardia or atrioventricular block. The cumulative effect of recurrent spells of a. is hypoxemia and shallow, nonrefreshing sleep, which may lead to excessive drowsiness, personality change, impairment of intellectual function, and heightened tendency to accidents during waking hours. However, evidence establishing obstructive sleep a. as an independent risk factor for motor vehicle accidents, heart attack, stroke, and sudden death is weak. About 15% of persons with this disorder develop sustained pulmonary hypertension. Obstructive sleep a. affects about 4% of men and 2% percent of women between the ages of 30 and 60. Obesity, hypothyroidism, cigarette smoking, alcohol, and some hypnotics (particularly benzodiazepines) predispose to this disorder, and its incidence increases with advancing age. Diagnosis is confirmed by polysomnography (continuous measurement of airflow, respiratory activity, chin electromyography, ECG, EEG, electrooculogram, and arterial oxygen saturation during sleep) and by evaluation of the shape and size of the upper respiratory tract. Weight loss, smoking cessation, and avoidance of benzodiazepine hypnotics are advised for all patients. A mandibular advancement appliance worn inside the mouth at night reduces symptoms in some patients. An effective if somewhat cumbrous treatment is the nightly use of continuous positive airway pressure, which provides a steady flow of room air at low pressure through the nose to overcome intermittent upper respiratory obstruction. Selected patients benefit from surgical procedures such as uvulopalatopharyngoplasty (trimming and reshaping of the uvula and soft palate), which can be performed by laser or radiofrequency ablation under local anesthesia, and mandibular osteotomy with genioglossus muscle advancement. sleep a. central and/or peripheral a. during sleep, associated with frequent awakening and often with daytime sleepiness. Cf.:sleep-induced a.. sleep-induced a. a. resulting from failure of the respiratory center to stimulate adequate respiration during sleep; divided into respiratory pause (cessation of air flow for less than 10 seconds) and apneic pause (cessation of air flow greater than 10 seconds).

apneic (ap′ne-ik)
Related to or suffering from apnea.

apneumia (a-pnoo′me-a)
Congenital absence of the lungs. [G. a- priv. + pneumon, lung]

apneusis (ap-noo′sis)
An abnormal respiratory pattern consisting of a pause at full inspiration; a prolonged inspiratory cramp caused by a lesion at the mid or caudal pontine level of the brainstem. [G. a- priv. + pneusis, a breathing, fr. pneo, to breathe]

Abbreviation for apoenzyme; apolipoprotein.

Combining form usually meaning separated from or derived from. [G. apo, away from, off; a. becomes ap-, especially before a vowel or h]

apobiosis (ap-o-bi-o′sis)
Death, especially local death of a part of the organism. [G. death, fr. apo, from, + biosis, life]

apocrine (ap′o-krin)
Denoting a mechanism of glandular secretion in which the apical portion of secretory cells is shed and incorporated into the secretion. SEE ALSO: a. gland. [G. apo-krino, to separate]

apocrustic (ap-o-krus′tik)
1. Astringent and repellent. 2. An agent with such action. [G. apokroustikos, able to beat off, fr. apo, off, + krouo, to strike]

apodal (a-po′dal)
Relating to apodia. SYN: apodous. [G. a- priv. + pous, foot]

apodia (a-po′de-a)
Congenital absence of feet. SYN: apody. [G. a- priv. + pous, foot]

apodous (ap′o-dus)
SYN: apodal.

apody (ap′o-de)
SYN: apodia.

apoenzyme (apo) (ap′o-en-zim)
The protein portion of an enzyme as contrasted with the nonprotein portion, coenzyme, or prosthetic portion (if present in the intact protein).

apoferritin (ap-o-fer′i-tin)
A protein in the intestinal wall that combines with a ferric hydroxide-phosphate compound to form ferritin, the first stage in the absorption of iron.

apogamia, apogamy (ap-o-gam′e-a, a-pog′a-me)
SYN: parthenogenesis. [G. apo, away, + gameo, to wed]

The peak of severity of the clinical manifestations of an illness. [Fr., fr. Mod. L. apogaeum, fr. G. apogaios, far from the earth, fr. apo, + gaia, earth]

apoinducer (a′po-in-doos′er)
A protein that binds to DNA to switch on transcription.


apolar (a-po′lar)
1. Without poles; denoting specifically embryonic nerve cells (neuroblasts) that have not yet begun to sprout processes. 2. SYN: hydrophobic (2) .


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