. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. â â IHP 'r^-Trrr VISION. 597 ihe respective 3 of the retina. « looked at wltli tbo' e right ey« when the eye is cioaed la rep- gures will give P, yet n to both eyes (sner reoscopes give on a flat sar- ts of the retina idea of solidity eyes (converg- iputed. It has ^r solid during â¢
. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. â â IHP 'r^-Trrr VISION. 597 ihe respective 3 of the retina. « looked at wltli tbo' e right ey« when the eye is cioaed la rep- gures will give P, yet n to both eyes (sner reoscopes give on a flat sar- ts of the retina idea of solidity eyes (converg- iputed. It has ^r solid during â¢o short to per- ich movement's inray; for while complex do, or, ed thereby. It that all visual which, not the md the mutual robably beyond ode to this sub- red to the shut- rvious to light, Eit he can locate mt; also that a y) from a light the head. The eous, secrete an inst the lachry- mal fluid, and prevents the latter running over their edges as oil would on the margins of a vessel. The lachrymal gland is not in structure unlike the parotid, the secretion of which its own somewhat resembles. The saltness of the tears, owing to abundance of sodium chloride, is well known to all. The nervous mechanism of se* cretion of tears is usually reflex, the stimulus coming from the action of the air against the eyeball or from partial desiccation owing to evaporation. When the eyeball itself, or the nose, is irritated, the afferent nerves are the branches of the fifth, to which also belong the efferent nerves. The latter include also the cervical sympathetic. But it will, of course, be understood that the afferent impulses r⢠'bederived through a large num- ber of nerves, and that i. > acreting cen- ter may be acted upon directly by the cerebrum (emotions). The excess of lach- rymal secretion is carried away by the nasal duct into which the lachrymal canals empty. While it is well known that closure of the lids by the orbicularis muscle favors the removal of the flui
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1880, bookyear1889
