| internal hydrocephalus | Hydrocephalus in which the accumulation of fluid is confined to the ventricles; also occurs as an autosomal recessive condition in the Hereford and Holstein breeds of cattle. (05 Mar 2000) |
|---|---|
| internal iliac lymph nodes | Nodes that lie along the internal iliac artery and its branches; they receive lymph from the pelvic viscera, the gluteal region, and the deep parts of the perineum, and send efferent vessels to the common iliac nodes. Synonym: nodi lymphatici iliaci interni. (05 Mar 2000) |
| internal iliac vein | <anatomy, vein> Runs from the upper border of the greater sciatic notch to the brim of the pelvis where it joins the external iliac vein to form the common iliac vein; it drains most of the territory supplied by the internal iliac artery. Synonym: vena iliaca interna. (05 Mar 2000) |
| internal inguinal ring | The opening in the transversalis fascia through which the ductus deferens (or round ligament in the female) and gonadal vessels enter the inguinal canal. Located midway between anterior superior iliac spine and pubic tubercle, it is bounded medially by the lateral umbilical ligament (inferior epigastric vessels) and inferiorly by the inguinal ligament. Indirect inguinal hernias exit the abdominal cavity via the deep inguinal ring Synonym: annulus inguinalis profundus, abdominal ring, annulus abdominalis, internal inguinal ring. (05 Mar 2000) |
| internal intercostal membrane | The membrane that replaces the internal intercostal muscle posteriorly, medial to the angles of the ribs. Synonym: membrana intercostalis interna. (05 Mar 2000) |
| internal intercostal muscle | <anatomy> Each arises from lower border of rib and passes obliquely downward and backward to be inserted into upper border of rib below; action, contract during expiration, also maintain tension in the intercostal spaces to resist mediolateral movement; nerve supply, intercostal. Synonym: musculus intercostalis internus. (05 Mar 2000) |
| internal jugular vein | <anatomy, vein> Main venouus structure of the neck, formed as a continuation of the sigmoid sinus of the dura mater, contained within the carotid sheath as it descends the neck uniting, behind the sternoclavicular joint, with the subclavian vein to form the brachiocephalic vein. Synonym: vena jugularis interna. (05 Mar 2000) |
| internal lacrimal fistula | A fistulous communication between the lacrimal sac and the ethmoidal sinus. Synonym: internal lacrimal fistula. (05 Mar 2000) |
| internal limiting membrane | Formed by the expanded inner ends of Muller's fibres, outer limiting membrane, not a membrane but a row of junctional complexes. Synonym: membrana limitans. (05 Mar 2000) |
| internal lip of iliac crest | The roughened inner margin of the crest that gives attachment to parts of the transversus abdominis, quadratus lumborum, and erector spinae muscles. Synonym: labium internum cristae iliacae. (05 Mar 2000) |
| internal male genital organs | The internal masculine genital organs, the testes, epididymides, deferent ducts, seminal vesicles, prostate, and bulbourethral glands. Synonym: organa genitalia masculina interna. (05 Mar 2000) |
| internal malleolus | The process at the medial side of the lower end of the tibia, forming the projection of the medial side of the ankle. Synonym: malleolus medialis, inner malleolus, internal malleolus. (05 Mar 2000) |
| internal medicine | The speciality of the general medicine of the internal organs. In the Commonwealth, the specialist in internal medicine is called a Physician (in the us, an Internist). (16 Dec 1997) |
| internal medullary lamina | See: medullary laminae of thalamus. (05 Mar 2000) |
| internal membrane | General term for intracellular membrane systems such as endoplasmic reticulum. Not particularly helpful, but has the advantage of being noncommittal. (18 Nov 1997) |