(bŭlb )

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

1. Any rounded or globular structure.
2. SEE: Medulla (3).

aortic bulb

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

auditory bulb

The membranous labyrinth of the inner ear.

duodenal bulb

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

end bulb

The enlarged bulb of the end of an axon.

end bulb of Krause

SEE: Krause, Wilhelm

hair bulb

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

bulb of the eye

SEE: Eyeball.

olfactory bulb

An anterior enlargement of the olfactory tract.

bulb of the penis

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

terminal bulb of Krause

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

bulb of the urethra

SEE: Urethral bulb.

urethral bulb

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

bulb of the vestibule

SEE: Vestibular bulb

vestibular bulb

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: SEE: bulb of the vestibule; SEE: bulbus vestibuli
SEE: Bartholin gland; SEE: vagina; SEE: vaginal vestibule