Poikilocytosis

A condition of the blood marked by irregularity in the shape of the red corpuscles; it occurs preeminently in pernicious anemia, but also in other forms of anemia. Poiiulothermal (poikilo-ther'- ma/). i'a thermic. Synonym of Poikilothermic. Varying in temperature according to the surroundings. A term applied to cold-blooded animals, the temperature of which adapts itself easily to their environment. t. an obin the mathematic sense,The that sharp which end has of position it no dimensions. P., Alveolar, the central point the lower margin of the upper alveolar arch. P. iphysaire, P., Apophyseal, a name given by rou eau to a tender spot over the spinous proce of vertebra, which, in neuralgic affections, corresponds the origin of the nerve involved. P., Auricular, craniometry, the center of the external auditory us. P., Boiling, the degree of temperature at hich a liquid pa es into the vaporous state with ebullition. P., Cardinal, in optics, one of the six points that determine the direction of the rays entering or emerging from a series of refracting media. P., Cardinal, of Capuron. See Pelvis . P., Craniometric. See Craniometric Points. P., Critical (of gases), a temperature at or above which a gas cannot be liquefied by pre ure alone. Different gases have different, but fixed critical points. P., Critical (of liquids), that temperature at which a liquid, regardle of the pre ure to which it is subjected, a umes a gaseous form. P., Deaf (of the ear), one of certain points near the ear where, as shown by Urbantschitsch, a vibrating tuning-fork cannot be heard. The fork is held perpendicularly and is moved from the zygoma backward toward the occiput. The first point is at the lower end of the tragus; the second, where the helix intersects the line along which the fork is moved. P., Dew, the temperature at which the atmospheric moisture is deposited as dew. P. of Dispersion, in optics, the virtual focus. Ps. douloureux, the tender spots at the exit of nerves the seat of neuralgic pain. See Ps., Valleix's. P. of Election, in surgery, that point at which a certain operation is done by preference. P., Erb's, the supra clavicular point, a point above the middle of the clavicle where a group of muscles consisting of the deltoid, biceps, brachial is amicus and supinator long us can be stimulated to contraction. P., Eye: i.