(bŭlb )

[L. bulbus, bulbous root, fr Gr. bolbos, truffle (?)]

aortic b.The dilated portion of the truncus arteriosus in the embryo that gives rise to the roots of the aorta and pulmonary arteries.

auditory b.The membranous labyrinth of the inner ear.

duodenal b.The upper duodenal area just beyond the pylorus. SYN: pyloric cap.

end b.The enlarged bulb of the end of an axon.

end b. of Krause

SEE: under Krause, Wilhelm.

hair b.The expand ed bulb at the lower end of the hair root. The growth of a hair results from the proliferation of cells of the hair bulb.

b. of the eye Eyeball.

olfactory b.An anterior enlargement of the olfactory tract.

b. of the penis The proximal enlarged bulb of the corpus spongiosum found between the two crura of the penis. SYN: bulbus penis.

terminal b. of Krause An encapsulated sensory nerve ending similar in structure to the corpuscles of Pacini.

b. of the urethra Urethral bulb.

urethral b.The posterior bulb of the corpus spongiosum found between the two crura of the penis. SYN: bulb of the urethra; bulbus corpus spongiosum.

b. of the vestibule Vestibular bulb

vestibular b.One of the two sacculated collections of veins, lying on either side of the vagina beneath the bulbocavernosus muscle, connected anteriorly by the pars intermedia, and communicating with the erectile tissue of the clitoris through this strip of cavernous tissue. The vestibular bulbs are the homologues of the male corpus spongiosum. Injury during labor may give rise to bleeding. SYN: bulb of the vestibule; bulbus vestibuli.

SEE: Bartholin gland ; vagina; vaginal vestibule.