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1. a small bladder or sac containing liquid.
2. a small circumscribed elevation of the epidermis containing a serous fluid; a small blister.
allantoic vesicle the internal hollow portion of the allantois.
auditory vesicle a detached ovoid sac formed by closure of the auditory pit in the early embryo, from which the percipient parts of the inner ear develop.
brain v's the five divisions of the closed neural tube in the developing embryo, including the telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon.
brain v's, primary the three earlier subdivisions of the embryonic neural tube, including the forebrain, midbrain, and hindbrain.
brain v's, secondary the four brain vesicles formed by specialization of the forebrain and of the hindbrain in later embryonic development.
chorionic vesicle the chorion of a mammal.
encephalic v's brain vesicles.
germinal vesicle the fluid-filled nucleus of an oocyte toward the end of prophase of its meiotic division.
lens vesicle a vesicle formed from the lens pit of the embryo, developing into the crystalline lens.
1. the vesicle in the embryo that later develops into the olfactory bulb and tract.
2. a bulbous expansion at the distal end of an olfactory cell, from which the olfactory hairs project.
optic vesicle an evagination on either side of the forebrain of the early embryo, from which the percipient parts of the eye develop.
otic vesicle auditory vesicle.
seminal vesicle paired sacculated pouches attached to the posterior urinary bladder; the duct of each joins the ipsilateral ductus deferens to form the ejaculatory duct.
umbilical vesicle the pear-shaped expansion of the yolk sac growing out into the cavity of the chorion, joined to the midgut by the yolk stalk.
one of two folded, sacculated, glandular structures that is a diverticulum of the ductus deferens; its secretion is one of the components of semen; it normally does not store spermatozoa as was previously thought.
Either of a pair of pouchlike glands situated on each side of the male urinary bladder that secrete seminal fluid and nourish and promote the movement of spermatozoa through the urethra.