‖ papilla
(pəˈpɪlə)
Pl. -æ.
[L., = nipple, dim. of papula swelling, pimple.]
1. Zool. and Anat. a. The nipple of the breast; the mamilla. (rare in Eng. use.)
| [1398 Trevisa Barth. De P.R. v. xxxiv. (Bodl. MS.), Þe tette þe heed of þe pappe hatte papilla in latyne.] 1693 tr. Blancard's Phys. Dict. (ed. 2), Papilla, a red Excrescency in the middle of the Breast. 1727–41 Chambers Cycl. s.v., The lacteal tubes, coming from the several parts of the breasts, terminate in the Papillæ. |
b. Any minute nipple-like protuberance, usually soft and fleshy, in a part or organ of the body:
e.g. those on the skin, specially abundant at the tips of the fingers and elsewhere, and constituting the apparatus for the sense of touch (tactile papillæ); those on the tongue (circumvallate papillae, conical papillae, filiform papillae, foliate papillae, and fungiform papillæ), most of which are connected with the sense of taste (gustatory papillæ); those at the tips of the Malpighian pyramids in the kidney (renal papillæ); those in the embryo which ultimately produce the teeth (dental papillæ); and those in various parts of insects and other invertebrates, esp. two malodorous organs which can be protruded from the abdomen in certain beetles. lachrymal papilla: a slight protuberance on the edge of the eyelid, traversed by the lachrymal duct. optic papilla: see optic A. 2.
| 1713 Derham Phys.-Theol. iv. vi. 144 Mr. Cowper hath..given us very elegant Cuts both of the skin, and the Papillae. 1748 Hartley Observ. Man i. i. 43 The nervous Papillae which are the immediate Organ in the Senses of Feeling, Taste, and Smell. 1844 Carpenter Princ. Hum. Phys. §316 The papillæ,..are little elevations of the surface of the cutis, easily perceptible by the aid of a lens. 1853 Ibid. (ed. 4) §279 The Dentinal pulp..makes its appearance in the form of a papilla, budding-out from the free surface of a fold or groove of the mucous membrane of the mouth. 1881 Mivart Cat 23 Each hair grows from a single dermal papilla only, of which it is the greatly prolonged epidermal covering. 1888 Rolleston & Jackson Anim. Life 551 [In Holothurioidea] The tube feet are either partially or completely retractile, and furnished with a terminal disc..or they are conical papillæ without discs. |
c. Path. A small papule or pimple.
| 1797 M. Baillie Morb. Anat. (1807) 152 Papillæ and pustules, somewhat resembling the small-pox. 1892 Syd. Soc. Lex., Papilla..Also, a diminutive of Papula. |
2. Bot. A small fleshy projection upon any part of a plant.
| 1848 Craig, Papillæ..in Botany, the minute puncta upon the surface of a leaf; the vesicles on leaves of twigs [etc.]. 1870 Hooker Stud. Flora 37 Pepperwort..papillæ scale⁓like when dry. 1885 G. L. Goodale Physiol. Bot. (1892) 155 In the earliest stage of its development the leaf is a mere papilla consisting of nascent cortex..and nascent epidermis. |