- 1. Any globular or fusiform structure. SYN: bulbus [TA]. 2. A short, vertical underground stem of plants, such as onion and garlic. [L. bulbus, a bulbous root]- aortic b. [TA] the dilated first part of the aorta containing the aortic semilunar valves and the aortic sinuses. SYN: arterial b., bulbus aortae.- dental b. the papilla, derived from mesoderm, that forms the part of the primordium of a tooth that is situated within the cup-shaped enamel organ.- end b. one of the oval or rounded bodies in which the sensory nerve fibers terminate in mucous membrane.- b. of eye SYN: eyeball.- b. of hair hair b., the lower expanded extremity of the hair follicle that fits like a cap over the papilla pili. SYN: bulbus pili, hair b..- b. of jugular vein [TA] one of two dilated parts of the internal jugular vein : (1) the superior b. (Heister diverticulum) is a dilation at the beginning of the internal jugular vein in the jugular fossa of the temporal bone (bulbus superior venae jugularis [TA]); (2) the inferior b. is a dilated portion of the vein just before it reaches the brachiocephalic vein (bulbus inferior venae jugularis [TA]). SYN: jugular b.. SYN: bulbus venae jugularis [TA].- Krause end bulbs nerve terminals in skin, mouth, conjunctiva, and other parts, consisting of a laminated capsule of connective tissue enclosing the terminal, branched, convoluted ending of an afferent nerve fiber; generally believed to be sensitive to cold. SYN: bulboid corpuscles, corpuscula bulboidea.- b. of occipital horn [TA] a rounded elevation in the dorsal part of the medial wall of the posterior horn of the lateral ventricle, produced by the major forceps. SYN: bulbus cornus posterioris [TA].- olfactory b. [TA] the grayish expanded rostral extremity of the olfactory tract, lying on the cribriform plate of the ethmoid and receiving the olfactory filaments. SYN: bulbus olfactorius [TA].- b. of penis [TA] the expanded proximal (posterior) part of the corpus spongiosum of the penis lying in the interval between the crura of the penis and containing the somewhat dilated and angulated portion of the spongy urethra. SYN: bulbus penis [TA], b. of corpus spongiosum, b. of urethra, bulbus urethrae.- speech b. a speech prosthesis used to close a cleft or other opening in the hard or soft palate, or to replace absent tissue necessary for the production of good speech.- b. of vestibule [TA] a mass of erectile tissue on either side of the vagina united anterior to the urethra by the commissura bulborum. SYN: bulbus vestibuli vaginae [TA].
* * *bulb 'bəlb n1) a rounded dilation or expansion of something cylindrical <the \bulb of a thermometer> esp a rounded or pear-shaped enlargement on a small base <the \bulb of an eyedropper>2) a rounded part: asa) a rounded enlargement of one end of a part see BULB OF THE PENIS, BULB OF THE VESTIBULE, END BULB, hair bulb, OLFACTORY BULBb) MEDULLA OBLONGATA broadly the hindbrain exclusive of the cerebellumc) a thick-walled muscular enlargement of the pharynx of certain nematode worms
* * *n.
* * *(bulb) [L. bulbus; Gr. bolbos] a rounded mass, or enlargement. See also bulbus.
Medical dictionary. 2011.