| extensor digitorum | <anatomy, muscle> Origin, lateral epicondyle of humerus; insertion, by four tendons into the base of the proximal and middle and base of the second and third phalanges of 4 fingers; action, extends fingers and hand; nerve supply, radial (posterior interosseous). Synonym: musculus extensor digitorum, extensor muscle of fingers, musculus extensor digitorum communis. (05 Mar 2000) |
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| extensor digitorum brevis | 1. <anatomy, muscle> (foot) Origin, dorsal surface of calcaneus; insertion, by four tendons fusing with those of the extensor digitorum longus, and by a slip attached independently to the base of the proximal phalanx of the great toe; action, extends toes; nerve supply, deep peroneal. Synonym: musculus extensor digitorum brevis, musculus extensor brevis digitorum, short extensor muscle of toes. 2. (hand) A short extensor muscle of the fingers of rare occurrence, and comparable to the short extensor of the toes. Synonym: musculus extensor digitorum brevis manus, Pozzi's muscle. (05 Mar 2000) |
| extensor expansion | A triangular tendinous aponeurosis including the tendon of the extensor digitorum centrally, interosseus tendons on each side, and a lumbrical tendon laterally. It covers the dorsal aspect of the metacarpophalangeal joint and the proximal phalanx. Synonym: dorsal hood, extensor aponeurosis, extensor expansion. (05 Mar 2000) |
| extensor indicis | <anatomy, muscle> Origin, dorsal surface of ulna; insertion, dorsal extensor aponeurosis of index finger; action, assists in extending the forefinger; nerve supply, radial. Synonym: musculus extensor indicis, index extensor muscle, musculus extensor indicis proprius. (05 Mar 2000) |
| extensor indicis proprius | <anatomy, muscle> Origin, posterior shaft of ulna and interossei membrane; insertion, tendon of extensor tendon of the index finger; action, extends and adducts index finger. (06 Mar 2000) |
| extensor pollicis brevis | <anatomy, muscle> Origin, dorsal surface of radius; insertion, base of proximal phalanx of thumb; action, extends and abducts the thumb; nerve supply, radial. Synonym: musculus extensor pollicis brevis, musculus extensor brevis pollicis, short extensor muscle of thumb. (05 Mar 2000) |
| extensor retinaculum | A strong fibrous band formed as a thickening of the antebrachial deep fascia, stretching obliquely across the back of the wrist, attaching deeply to ridges on the dorsal aspect of the radius, triquetral and pisiform bones, binding down the extensor tendons of the fingers and thumb. Synonym: retinaculum extensorum, dorsal carpal ligament, ligamentum carpi dorsale. (05 Mar 2000) |
| annular part of fibrous digital sheath | One of the two circular fibrous bands of the fibrous sheaths of the fingers and toes attached to the shaft of the proximal and middle phalanges. Synonym: pars annularis vaginae fibrosae, annular pulley, annulus of fibrous sheath, ligamentum annulare digitorum. (05 Mar 2000) |
| annulus of fibrous sheath | One of the two circular fibrous bands of the fibrous sheaths of the fingers and toes attached to the shaft of the proximal and middle phalanges. Synonym: pars annularis vaginae fibrosae, annular pulley, annulus of fibrous sheath, ligamentum annulare digitorum. (05 Mar 2000) |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |
| arcuate line of rectus sheath | A crescentic line, not always clearly defined, which marks the lower limit of the posterior layer of the sheath of the rectus abdominis muscle. Synonym: linea arcuata vaginae musculi recti abdominis, Douglas' line, linea saemicircularis, saemicircular line. (05 Mar 2000) |
| axillary sheath | Fibrous neurovascular sheath, formed as an extension of the prevertebral layer of deep cervical fascia through the cervicoaxillary canal, which enclosed the first part of the axillary artery, the axillary vein, and the brachial plexus. (05 Mar 2000) |
| carotid sheath | The dense fibrous investment of the carotid artery, internal jugular vein, and vagus nerve on each side of the neck, deep to the sternocleidomastoid muscle; the layers of cervical fascia blend with it. Synonym: vagina carotica. (05 Mar 2000) |
| rectus sheath | Sheath of the rectus abdominis, formed by the aponeuroses of the three anterolateral muscles of the abdominal wall that split to enclose the rectus and fuse medially to form the linea alba; it consists of an anterior lamina and a posterior lamina, the latter being absent below the arcuate line. See: aponeurosis of external abdominal oblique muscle, aponeurosis of internal abdominal oblique muscle. Synonym: vagina musculi recti abdominis. (05 Mar 2000) |
| parotid sheath | The part of the investing cervical fascia that ensheaths the parotid gland and is fixed above to the zygomatic arch. Synonym: fascia parotidea, fibrous capsule of parotid gland, parotid sheath. (05 Mar 2000) |