DICT.TW Dictionary Taiwan

 Pal·li·al a.  Zool. Of or pertaining to a mantle, especially to the mantle of mollusks; produced by the mantle; as, the pallial line, or impression, which marks the attachment of the mantle on the inner surface of a bivalve shell. See Illust. of Bivalve.
 Pallial chamber Zool., the cavity inclosed by the mantle.
 Pallial sinus Zool., an inward bending of the pallial line, near the posterior end of certain bivalve shells, to receive the siphon. See Illust. of Bivalve.
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 Si·nus n.; pl. L. Sinus, E. Sinuses
 1. An opening; a hollow; a bending.
 2. A bay of the sea; a recess in the shore.
 3. Anat. & Zool. A cavity; a depression. Specifically: (a) A cavity in a bone or other part, either closed or with a narrow opening. (b) A dilated vessel or canal.
 4. Med. A narrow, elongated cavity, in which pus is collected; an elongated abscess with only a small orifice.
 5. Bot. A depression between adjoining lobes.
 Note: ☞ A sinus may be rounded, as in the leaf of the white oak, or acute, as in that of the red maple.
 Pallial sinus. Zool. See under Pallial.
 Sinus venosus [L., venous dilatation.] Anat. (a) The main part of the cavity of the right auricle of the heart in the higher vertebrates. (b) In the lower vertebrates, a distinct chamber of the heart formed by the union of the large systematic veins and opening into the auricle.
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