presentation (redirected from Antigen presentation)

presentation /pre·sen·ta·tion/ (pre?zen-ta´shun) that part of the fetus lying over the pelvic inlet; the presenting body part of the fetus. Cf. position and lie.

Presentation of fetus.

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antigen presentation  the hypothesis that macrophages not only ingest and process antigen, refining and complexing it with SRNA, but also present it in concentrated form at their surfaces to lymphocytes, thus inducing an immune response by the lymphocytes.

breech presentation  presentation of the fetal buttocks or feet in labor; the feet may be alongside the buttocks (complete breech p.); the legs may be extended against the trunk and the feet lying against the face (frank breech p.); or one or both feet or knees may be prolapsed into the maternal vagina (incomplete breech p.) .

brow presentation  presentation of the fetal brow in labor.

cephalic presentation  presentation of any part of the fetal head in labor, whether the vertex, face, or brow.

compound presentation  prolapse of a limb of the fetus alongside the head in a cephalic presentation or of one or both arms in a breech presentation.

footling presentation  presentation of the fetus with one (single footling) or both (double footling) feet prolapsed into the maternal vagina.

funis presentation  presentation of the umbilical cord in labor.

placental presentation  placenta previa.

shoulder presentation  presentation of the fetal shoulder in labor; see oblique lie and transverse lie.

transverse presentation  see under lie.

vertex presentation  that in which the vertex of the fetal head is the presenting part.

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pres·en·ta·tion (przn-tshn, przn-)

n.

1. The act of presenting.

2. The position of the fetus in the uterus at the beginning of labor, described in terms of the part that emerges or is felt first.

3. The part of the fetal body in advance during birth.

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presentation

lie; the relationship of the long axis of the fetus to that of the dam. In foals and ruminants the normal presentation of a fetus during parturition is with the forelimbs extended forward so that the hooves are presented first, followed by the head between the forearms, followed by the trunk, abdomen and lastly the hindlimbs extended backward, i.e. anterior presentation.

In piglets the usual presentation is the nose first followed by the shoulders with the forelimbs beside the trunk, followed by the hindlimbs extended backward. The nose of puppies and kittens is presented first with the front paws forward under the neck and chin.

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anterior presentation

presentation of the front feet and limbs followed by the fetal head in labor.

breech presentation

presentation of the fetal buttocks and tail in labor.

funic presentation

presentation of the umbilical cord in labor.

poll presentation

the fetus is presented with the forelimbs retained and the neck flexed so that the poll is presented in the cervix.

posterior presentation

the hindfeet are presented followed by the hindlimbs and hindquarters and tail; a normal variation in dogs and pigs.

transverse presentation

at birth the fetus is presented at the pelvic inlet with its long axis running across the long axis of the pelvic canal in the dorsotransverse position. It is the back of the fetus that can be palpated. There are no fetal parts with which to effect a correction.

Transverse presentation in a mare. By permission from Parkinson TJ, England GCW, Arthur GH, Arthur's Veterinary Reproduction and Obstetrics, Saunders, 2001

ventral head presentation

the fetus presents with the head and neck flexed beneath the body. Called also neck flexion.