bulb. 1

In general, any rounded, more or le spherical, or ovoid body, whether solid or hollow. 2. In botany, an abbreviated, more or le globular plant axis, enveloped above by an aggregation _ of fleshy leaves (a leaf bud) and bearing roots below, also a swollen portion of the pedicle of certain fungi, aortic b. The expanded initial portion of the aorta; in embryology, the aortic (or primitive arterial) stem (see arterial b.); in comparative anatomy, a bulbous enlargement of the cardiac aorta which contains striped muscular fibers and contracts rhythmically. arterial b. Of the embryonic heart, the anterior portion, which by division gives rise to the aortic and pulmonary stems. b. of the corpus caver no sum. An enlargement of the crus of the corpus caver no sum at the root of the penis. b. of the corpus spongiosum. See b. of the urethra, b. of the eye. The} eyeball, b. of the fornix. See splenium. b. of the olfactory nerve. See olfactory b. b. of the spinal cord. See medulla oblong at a. b. of the urethra. A bulbous expansion of the proximal end of the corpus spongiosum urethrae. b's of the vagina, b's of the vestibule. See bulb i vestibuli vaginae, under bulb us. central b. The core of a terminal nerve corpuscle, cylindrical end b. See end bud, under separate heading. fornix b's. See splenium. four b's. See corpora quadrigemina, under corpora, gustatory b's. See tastd buds, under bud. naked, b. A b. (in the botanical sense) with loose, separable scales, olfactory b. An oblong body, consisting almost entirely of gray matter, resting on the cribriform plate of the ethmoid bone, through the perforations of which it sends down nerve filaments from its lower surface to enter the nose. proximal b. Of a cilium of a ciliated cell, that portion which is next the cell and connected with it by the intermediate segment, taste b's. See taste buds, under bud. terminal nerve b. See end bud, under separate head. [Lat, bulb us, a bulbous root.]