ASTHMATIC 



144 



ATAVISM 



Synonym of Bronchial Asthma. A., Thymic. Syn- 

 onym of Laryngismus stridulus. A. uteri. Syn- 

 onym of Hysteria. 



Asthmatic (az-mat'-ik) [aad/ia, panting]. Relating to 

 or affected with asthma. 



Astigmagraph [as-tig' '-ma-graf) [a priv. ; ariyfia, a 

 point ; ypdipeiv, to write] . An instrument for illustrat- 

 ing the phenomena of astigmatism. 



Astigmatic (as-tig-maf '-ik) [a priv. ; ariyfia, a point] . 

 Pertaining to or affected with astigmatism. 



Astigmatism [as-tig' -mat-izm) [a priv. ; ariyfia, a point, 

 because rays of light from a point are never brought to 

 a point by the refractive media of the eye] . That 

 condition of the eye wherein homocentric rays of light 

 are not brought to a focus by the media. It is usually 

 due to inequality of curvature of the different merid- 

 ians of the cornea (corneal A.), but may be caused by 

 imperfections of the lens (lenticular), unequal con- 



Diagram Illustrating ths Formation of Astigmatic 

 Images. 



The figures below give the images corresponding to the posi- 

 tions of the perpendicular lines above. The vertical rays 

 are brought to a focus anterior to the horizontal. V. = ver- 

 tical rays ; H. = horizontal. 



traction of the ciliary muscle, or may perhaps be due 

 to retinal imperfection. It may be acquired or con- 

 genital, and may complicate hypermetropia or myopia, 

 producing either simple hypermetropic A., in which 

 one principal meridian is emmetropic, the other hyper- 

 metropic ; or compound hypermetropic A., in which 

 both meridians are hypermetropic, but one more so 

 than the other. Complicating myopia, we may in the 

 same way have simple myopic or compound myopic 

 A. In mixed A., one principal meridian is myopic, 

 the other hypermetropic. Regular A. is when the 

 two principal meridians are at right angles to each other. 

 Irregular A., when different parts of a meridian have 

 different refracting powers. 



Astigmatometer [as-tig-mat-om' '-et-er) [a priv. ; ariyfia, 

 a point ; fitrpov, a measure] . An instrument for 

 measuring the degree of astigmatism. 



Astigmometer (as-tig-mom' '-et-er). See Astigmatom- 

 eter. 



Astigmometry (as-tig-mom' -et-re) [d priv. ; ariyfia, a 

 point ; fitrpov, a measure] . The measurement of astig- 

 matism. 



Astomous (ah-sto'-mus) [a priv. ; ard/ia, mouth]. In 

 biology, without a mouth or aperture. 



Astragalectomy (as-trag-al-ek' -to-me) [aarpayalog, 

 astragalus ; inrofir/, excision]. Surgical excision of 

 the astragalus. 



Astragaloscaphoid [as-trag-al-o-skaf -oid) [aarpdya- 

 Tuoq, astragalus; aKa<po£i6fc, like a boat]. Relating to 

 the astragalus and the scaphoid bone. 



Astragalotibial [as-trag-al-o-tib' -e-al) [aarpdyaAoq, 

 astragalus; tibia, the shin-bone]. Relating to the 

 astragalus and the tibia. 



Astragalus (as-trag'-al-us) [darpdyahog, a dice ; the ana- 

 logous bones of the sheep were used by the ancients 

 as dice]. The ankle-bone, upon which the tibia rests. 

 Also, a genus of leguminous plants from some varieties 

 of which gum tragacanth is derived. A. mollissi- 

 mus, Loco Plant. The active principle of this plant 

 has mydriatic properties. Unof. 



Astrapaphobia [as-trap-af-o' -be-ali) [darpanrj, light- 

 ning; oo/3oc, fear]. Morbid and unreasonable fear 

 of lightning. 



Astraphobia [as-trah-fo' '-be-ah). See Astrapaphobia. 



Astriction [as-trik 1 '-shun) [astrictio ; ad, to ; stringere, to 

 bind] . Constipation or any condition resulting from the 

 use of astringents. 



Astringency (as-trin' -jen-se) [ad, to; stringere, to bind]. 

 The quality of being astringent. 



Astringent [as-trin' -jent) [ad, to; stringere, to bind]. 

 I. Causing contraction; binding. 2. An agent pro- 

 ducing contraction of organic tissues, or that arrests 

 hemorrhages, diarrheas, etc. Tannin, alum, opium, 

 alcohol, the salts of silver, lead, etc., are examples. 



Astrokinetic (as-tro-kin-ef -ik) [darpov, a star ; mveiv, 

 to move] . In biology, applied by Ryder to the pheno- 

 mena of motion as exhibited by the centrosomes of 

 cells. 



Astrostatic [as-tro-stat'-ik) [darpov, a star ; laraadai, to 

 stand]. In biology, applied by Ryder to the resting 

 condition of the centrosomes of cells. 



Asylum (as-i'-lum) [asylum, a place of refuge]. An 

 institution for the support, safe-keeping, cure, or edu- 

 cation of those incapable of caring for themselves, such 

 as the insane, the blind, etc. A. Ear. See Hematoma 

 atiris, and Ear Deformities. 



Asymbolia [ah-sim-bo' -le-ah) [a priv. ; avfifioAov, sym- 

 bol]. The loss of all power of communication, even 

 by signs or symbols. 



Asymmetry (ah-sim' -et-re) [a priv. ; avfifierpia, sym- 

 metry]. I. Unlikeness of corresponding organs or 

 parts of opposite sides of the body that are normally 

 of the same size, etc., as e.g., asymmetry of the two 

 halves of the skull or brain. 2. The linking of carbon 

 atoms to four different groups ; the combination of 

 carbon atoms with different atoms or atomic groups. 



Asynergia (ah-sin-er' -je-ah) [a priv. ; ovvepyia, co- 

 operation]. Faulty coordination of the different or- 

 gans or muscles normally acting in unison. 



Asynesia (as-in-e'-ze-ah) [davveaia, stupidity]. Stupid- 

 ity ; loss or disorder of mental power. 



Asynodia (ah-sin-o' -de-ah) [a priv. ; avvodia, a travel- 

 ling together] . Impotence. 



Asystematic (ah-sis-tem-af -ik) [a priv. ; avarrjfia, 

 system]. Diffuse ; not restricted to any one or several 

 systems of nerve fibers ; applied to nervous diseases 

 that are general. 



Asystole (ah-sis' -to-le) [a priv ; avarolif, a shortening] . 

 Absence or imperfection of the cardiac systole, due 

 to feebleness, dilatation, etc., of the heart. 



Asystolic [ah-sis-tol'-ik) [a priv ; avarolif, a shorten- 

 ing]. Marked by, due to, or suffering from asystole. 



Asystolism (ah-sis' -tol-izm) [a priv. ; ovaro'Ar/, a shorten- 

 ing] . Inability of the right ventricle of the heart to 

 empty itself of its contents, a condition encountered in 

 the last stages of mitral incompetence. See Asystole. 



Asystoly [ah-sis' -to-le) . Same as Asystole. 



Atactic (at-ak'-lir) [ara/crof, irregular]. Irregular, 

 incoSrdinate. Pertaining to muscular incoordination, 

 especially in aphasia. Also applied to atypical fevers. 



Atavic (at-av'-ik) [atavus, a forefather]. Relating to 

 or characterized by atavism. 



Atavism (at'-av-izm) [atavus, a forefather]. The re- 

 appearance of an anomaly, physical, mental, or patho- 

 logic, in an individual whose more or less remote 



