| external hydrocephalus | Accumulation of fluid in the subarachnoid spaces of the brain, accumulation of fluid in the subdural space owing to a persistent communication between the subarachnoid and subdural spaces. (05 Mar 2000) |
|---|---|
| external iliac artery | <anatomy, artery> Origin, common iliac; branches, inferior epigastric, deep circumflex iliac; becomes the femoral at the inguinal ligament. Synonym: arteria iliaca externa. (05 Mar 2000) |
| external iliac lymph nodes | Nodes located in association with the external iliac vein; they are subdivided into three groups: intermediate external iliac lymph nodes, between the vein and the external iliac artery; lateral external iliac lymph nodes, and medial external iliac lymph nodes, medial to the vein; they all receive afferent vessels from the inguinal nodes, lower abdominal wall, and pelvic viscera, and send efferent vessels to the common iliac nodes. Synonym: nodi lymphatici iliaci externi. (05 Mar 2000) |
| external iliac plexus | A lymphatic plexus formed by the lymph nodes along the external iliac artery on either side, and their afferent and efferent vessels. Synonym: plexus iliacus externus. (05 Mar 2000) |
| external iliac vein | <anatomy, vein> A direct continuation of the femoral vein superior to the inguinal ligament, uniting with the internal iliac vein to form the common iliac vein. Synonym: vena iliaca externa. (05 Mar 2000) |
| external inguinal ring | The slit-like opening in the aponeurosis of the external oblique muscle of the abdominal wall through which the spermatic cord (round ligament in the female) and inguinal hernias emerge from the inguinal canal. See: aponeurosis of external abdominal oblique muscle. Synonym: annulus inguinalis superficialis, external inguinal ring, subcutaneous ring. (05 Mar 2000) |
| external intercostal membrane | The membrane that replaces the external intercostal muscle anteriorly between costal cartilages. Synonym: membrana intercostalis externa. (05 Mar 2000) |
| external intercostal muscles | Each arises from lower border of one rib and pass obliquely downward and forward to be inserted into the upper border of rib below; action, contract during inspiration, also maintain tension in the intercostal spaces to resist mediolateral movement; nerve supply, intercostal. Synonym: musculus intercostales externi. (05 Mar 2000) |
| external jugular vein | <anatomy, vein> Superficial vein formed inferior to the parotid gland by the junction of the posterior auricular vein and the retromandibular vein, and passes down the side of the neck crossing to the sternocleidomastoid muscle vertically to empty into the subclavian vein. Synonym: vena jugularis externa. (05 Mar 2000) |
| external lip of iliac crest | The roughened outer margin of the crest that gives attachment to the external oblique and latissimus dorsi muscles above and to the fasciae latae and the tensor fascia lata muscle below. Synonym: labium externum cristae iliacae. (05 Mar 2000) |
| external male genital organs | The external masculine genital organs, the penis and scrotum. Synonym: organa genitalia masculina externa. (05 Mar 2000) |
| external malleolar sign | <clinical sign> When the external malleolar skin area is irritated, extension of the great toe occurs in cases of organic disease of the corticospinal reflex paths. Synonym: Chaddock reflex, external malleolar sign. (05 Mar 2000) |
| external malleolus | The process at the lateral side of the lower end of the fibula, forming the projection of the lateral part of the ankle; the lateral malleolus is more inferiorly placed then the medial malleolus. Synonym: malleolus lateralis, external malleolus, extramalleolus, outer malleolus. (05 Mar 2000) |
| external mammary artery | <anatomy, artery> Origin, axillary; distribution, muscles of chest and mammary gland. Synonym: arteria thoracica lateralis, external mammary artery, long thoracic artery. (05 Mar 2000) |
| external matrix | The substance occupying the space between the inner and outer membrane of any organelle (e.g., mitochondria) with a double membrane. (05 Mar 2000) |