Éléments de l'anatomie de Quain . ording à la couleur de l'œil. Au niveau de la surface postérieure se trouve une couche de pigment sombre, l'uvéa des auteurs ; il s'agit de la couche pigmentaire (rétinienne) qui recouvre les processus ciliaires, et des héréco-sistes de plusieurs strates de petites cellules roundish remplies de granules de pigment noirs. La couleur de l'iris dépend du pigment dans les cellules stroma; dans les différentes nuances de l'œil bleu, il provient du pigmentnoir de la surface postérieure apparaissant plus ou moins par le stroma, qui dans de tels cas est légèrement coloré ou incolore; mais dans le theblac

• Contributeur: The Reading Room
• ID de l’image: 2AWG93Y
• Taille du fichier: 7,1 MB (500,8 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 1958 x 1276 px | 33,2 x 21,6 cm | 13,1 x 8,5 inches | 150dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

Quain's elements of anatomy . ording to the colour of the eye. At the posterior surfaceis a covering of dark pigment, the uvea of authors ; this is continuouswith the (retinal) pigmentary layer lining the ciliary processes, and hereconsists of several strata of small roundish cells filled with black pigment-granules. The colour of the iris depends on the pigment in the stroma-cells; in the different shades of blue eye it arises from the black pigmentof the posterior surface appearing more or less through the stroma, which in such cases is only slightly coloured or is colourless ; but in theblack, brown, and grey eye, the colour is due to the pigment-cellsscattered through the substance of the stroma itself. The muscular tissue is of the non-striated kind, and is disposed asa ring {sphincter) around the pupil, and as rays {dilafator) from thesphincter to the circumference. The sphincter (fig. 341, a) is a narrow band about -£^ of an inchwide, situated close to the pupil posteriorly. Near the margin of the Fig. 341.. Fig. 341.—Segment op the iris, SEEN FROM THE POSTERIOR SUR-FACE AFTER REMOVAL OF THEUVEAL PIGMENT (Iwanoff). a, sphincter muscle ; 6, dilatatormuscle of the pupil. pupil the fibres are closetogether, but the outermostfibres are more separated, and form less completerings. The dilafator (b), lessapparent than the sphincter, begins at the ciliary or outer margin of the iris, and its fibres, forminga continuous membrane close to the posterior surface, converge towardsthe pupil. Here they bend round and blend with the sphincter, somereaching nearly to its inner margin. At their origin at the ciliarymargin, they also arch round and take a somewhat circular direction. Vessels of the iris.—The lorn/ ciliary arteries, two in number, piercethe sclerotic a little in advance, and one on each side, of the optic nerve.Having gained the interval between the sclerotic and choroid coats, they extend horizontally forwards (figs. 337, 338, h, fig. 342, 1) coveredby loose

Recherche dans la banque de photos par tags

• bookcentury1800
• booksubjecthumananatomy
• huer
• livresubjectanatomy