| anal triangle | The posterior portion of the perineal region through which the anal canal opens; bounded by a line through both isehial tuberosities, the sacrotuberous ligaments and the coccyx. Synonym: regio analis, anal region. (05 Mar 2000) |
|---|---|
| anterior triangle of neck | The area of the neck bounded by the mandible, the anterior border of the sternocleidomastoid muscle, and the anterior midline of the neck; it is subdivided into carotid, muscular, submandibular, and submental triangles. Synonym: anterior region of neck, regio cervicalis anterior, trigonum cervicale anterius. (05 Mar 2000) |
| Assezat's triangle | A triangle formed by lines connecting the nasion with the alveolar and nasal point; used to indicate prognathism in comparative craniology. (05 Mar 2000) |
| auricular triangle | A triangle formed by the base of the auricle and by lines drawn from the true tip of the auricle to the extremities of the base. (05 Mar 2000) |
| axillary triangle | A triangular area embracing the medial aspect of the arm, the axilla, and the pectoral region which is one of the seats of predilection for the petechial initial rash of smallpox. (05 Mar 2000) |
| Beclard's triangle | Area bounded by the posterior border of the hyoglossus muscle, the posterior belly of the digastric and the greater horn of the hyoid bone. (05 Mar 2000) |
| Bonwill triangle | An equilateral triangle formed by lines from the contact points of the lower central incisors, or the medial line of the residual ridge of the mandible, to the condyle on either side and from one condyle to the other. (05 Mar 2000) |
| Bryant's triangle | In fracture of the neck of the femur to determine upward displacement of the trochanter, lines are drawn on the body to form a triangle: line a is drawn around the body at the level of the anterior superior iliac spines; line b, perpendicular to line a, is drawn to the great trochanter of the femur; line c is drawn from the trochanter to the iliac spine; upward displacement is measured along line b. Synonym: iliofemoral triangle. (05 Mar 2000) |
| Burger's triangle | A scalene triangle representing the frontal plane electrocardiographic leads comparable to but more accurate than Einthoven's triangle. See: Einthoven's triangle. (05 Mar 2000) |
| Burow's triangle | A triangle of skin and subcutaneous fat excised so that a pedicle flap can be advanced without buckling the adjacent tissue. (05 Mar 2000) |
| Calot's triangle | Triangle bounded by the cystic artery, cystic duct, and hepatic duct; its dissection early in cholecystectomy safeguards essential structures, should there be anatomic variations from the norm. (05 Mar 2000) |
| cardiohepatic triangle | The angle formed by the upper border of the liver and the right border of the heart, especially as defined by percussion. Synonym: cardiohepatic triangle. (05 Mar 2000) |
| Macewen's triangle | A triangle formed by the root of the zygomatic arch, the posterior wall of the bony external acoustic meatus, and an imaginary line connecting the extremities of the first two lines; used as a guide in mastoid operations. Synonym: Macewen's triangle. (05 Mar 2000) |
| palatal triangle | A triangular area bounded by the greatest transverse diameter of the palate and by lines converging from its extremities to the alveolar point. Synonym: trigonum palati. (05 Mar 2000) |
| Garland's triangle | A triangular area of relative resonance in the lower back near the spine, found in the same side as a pleural effusion. (05 Mar 2000) |