| PIV | parainfluenza virus; polydactyly-imperforate anus-vertebral anomalies [syndrome]; projective image v... |
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| VATER | vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia |
| imperforate anus | <embryology, paediatrics> A congenital obstruction of the anal opening. Occurs in approximately 1 in 5,000 infants. This condition is corrected through surgery. (27 Sep 1997) |
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| internal sphincter muscle of anus | <anatomy> A smooth muscle ring, formed by an increase of the circular fibres of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter. This sphincter is maximally-contracted when the rectal ampulla is at rest -empty or relaxed to accommodate a distending faecal mass. It is inhibited with filling of the ampulla, increased distension and peristalsis. Synonym: musculus sphincter ani internus, internal sphincter muscle of anus. (05 Mar 2000) |
| elevator muscle of anus | <anatomy> Formed by pubococcygeus and iliococcygeus muscles; origin, posterior body of pubis, tendinous arch of the levator ani, and spine of ischium; insertion, anococcygeal ligament, sides of the lower part of the sacrum and of coccyx; action, resists prolapsing forces and draws the anus upward following defecation; supports the pelvic viscera; nerve supply, nerve to levator ani (fourth sacral spinal nerve). Synonym: musculus levator ani, elevator muscle of anus. (05 Mar 2000) |
| external sphincter muscle of anus | A fusiform ring of striated muscular fibres surrounding the anus, attached posteriorly to the coccyx and anteriorly to the central tendon of the perineum; it is subdivided, often indistinctly, into a subcutaneous part, a superficial part and a deep part for descriptive purposes. Synonym: musculus sphincter ani externus, external sphincter muscle of anus. (05 Mar 2000) |