bulb

[L. bulb us, a bulbous root.] 1. An underground leaf-bud in which the leaves are superimposed on each other to form a rounded ma . 2. Any globular or fusiform structure. 3. Medulla oblong at a, aor'tic b. the first of the four dilatations of the primitive heart in the embryo, arte'rial b., aortic b. b. of the cor'pus cavemo's um, bulb us* urethrse. b. of the eye, eyeball, globe of the eye. b. of the ure'thra, bulb us* urethras, b. of the ves'tibule, bulb us* vestibuli, den'tal b., the papilla, derived from the mesoblast, which forms the germ of the tooth. end-b., one of the oval or rounded bodies in which the sensory nerve fibers terminate in mucous membrane, hair-b., bulb us* pili. ju'gular b., bulb us* vense jugular is. olfac'tory b., bulb us* olfact or i us. rachid'ian b., medulla oblong at a. taste-b., one of the bulbous bodies in the papillae of the tongue in which the gustatory nerves terminate.