Bulb

I. The expansion or dilatation of a canal or ve el. 2. Applied to the oblong at a and pons. 3. A short underground stem covered with fleshy leaf-bases or fleshy leaves, as the onion and squill. B. of Aorta, the dilatation of the aorta near its beginning. B. of Corpus Caver no sum, the muscle beneath the bulb of the urethra. B. of an Eye, the eyeball. B. of Fornix. See Corpora . B. of a Hair, the swelling at the root of a hair. B., Olfactory, the expanded end of the narrow olfactory lobe, commonly called olfactory nerve or first cranial nerve. B. of a Tooth, the papilla that forms the germ of a tooth. B. of Urethra, the posterior expanded part of the corpus spongiosum penis. B. of the Vagina, a small body of erectile ti ue on each side of the vestibule of the vagina, homologous to the bulb of the urethra of the male. B. of Vena Jugular is, the dilatation at the beginning of the external jugular vein.