fornix

fornix /for·nix/ (for´niks) pl. for´nices   [L.]

1. an archlike structure or the vaultlike space created by such a structure.

2. fornix of brain; either of a pair of arched fiber tracts that unite under the corpus callosum, so that together they comprise two columns, a body, and two crura.

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for·nix (fôrnks)

n. pl. for·ni·ces (-n-sz)

1. An arch-shaped structure, especially the arch-shaped roof of an anatomical space.

2. The compact bundle of white fiber by which the hippocampus of each cerebral hemisphere projects to the opposite hippocampus and to the septum, the anterior nucleus of the thalamus, and the mamillary body.

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fornix

[fôr′niks] pl. fornices

Etymology: L, arch

an archlike structure or space, such as the fornix cerebri, the superior or inferior conjunctival fornices, or the vaginal fornices.

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fornix

pl. fornices [L.] an archlike structure or the vaultlike space created by such a structure.

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cerebral fornix

either of a pair of arched fiber tracts that unite under the corpus callosum, so that together they comprise two columns, a body, and two crura.

conjunctival fornix

line of reflexion of the conjunctiva from the eyelid to the eyeball.

hippocampal fornix

a thick bundle of nerve fibers leaving the hippocampus to enter the hypothalamus, terminating in the mamillary body.

telencephalic fornix

see cerebral fornix (above).

vaginal fornix

the annular recess around the outside of the cervix.

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conjunctiva 

A thin transparent mucous membrane lining the posterior surface of the eyelids from the eyelid margin and reflected forward onto the anterior part of the eyeball where it merges with the corneal epithelium at the limbus. It thus forms a sac, the conjunctival sac, which is open at the palpebral fissure and closed when the eyes are shut. The depths of the unextended sac are 14-16 mm superiorly and 9-11 mm inferiorly. The conjunctiva is divided into three portions: (1) The portion that lines the posterior surface of the eyelids is called the palpebral conjunctiva. It is itself composed of the marginal conjunctiva, which extends from the eyelid margin to the tarsal conjunctiva; the tarsal conjunctiva, which extends from the marginal conjunctiva to the orbital conjunctiva; and the orbital conjunctiva, which extends from the tarsal conjunctiva to the fornix. (2) That lining the eyeball is the bulbar conjunctiva. It is itself composed of the limbal conjunctiva, which is fused with the episclera at the limbus and the scleral conjunctiva, which extends from the limbal conjunctiva to the fornix. (3) The intermediate part forming the bottom of the conjunctival sac, unattached to the eyelids or the eyeball and joining the bulbar and the palpebral portion is called the fornix (conjunctival fold, cul-de-sac). See dyskeratosis; lid eversion; conjunctival gland; Krause's end bulbs; subtarsal sulcus.