| LM | lactic acid mineral [medium]; lactose malabsorption; laryngeal mask; laryngeal muscle; lateral malle... |
|---|---|
| long | longitudinal |
| LPC | late positive component; lipocortin; longitudinal primary care [program]; lysophosphatidylcholine |
| LS | lateral suspensor; left sacrum; left septum; left side; legally separated; leiomyosarcoma; length of... |
| L/S | lactase/sucrase [ratio]; lecithin/ sphingomyelin [ratio]; lipid/saccharide [ratio]; longitudinal sec... |
| longitudinal sinus | See: inferior sagittal sinus, superior sagittal sinus. Longitudinal vertebral venous sinus, large, plexiform veins forming portions of the anterior internal vertebral venous plexus lying on the posterior surfaces of the vertebral bodies on either side of the posterior longitudinal ligament. Synonym: sinus vertebrales longitudinales. Luschka's sinus, venous sinus in the petrosquamous suture. (05 Mar 2000) |
|---|---|
| longitudinal studies | Studies in which variables relating to an individual or group of individuals are assessed over a period of time. (12 Dec 1998) |
| longitudinal study | <epidemiology> A study taking place over time. If individuals are followed, this is a longitudinal cohort study. If individuals are not followed, but classes (usually age classes) are restudied, this is a longitudinal cross-sectional study. The converse of a horizontal study. (05 Dec 1998) |
| longitudinal sulcus of heart | See: anterior interventricular groove, posterior interventricular groove. (05 Mar 2000) |
| longitudinal wave | <physics> Waves where the variation of the field is partially or totally in the direction of propagation (parallel to wavennumber, k [a vector]). Examples include sound waves and Langmuir waves. Contrasted with transverse waves, where the variation is perpendicular to the direction of propagation, such as light waves. (13 Nov 1997) |
| abdominal canal | A passage in the lower anterior abdominal wall which in the male allows passage of the spermatic cord and in the female contains the round ligament. Because of the weakness it creates in the abdominal wall, it is the most frequent site for a hernia. (12 Dec 1998) |
| accessory canal | A channel leading from the root pulp laterally through the dentin to the periodontal tissue; may be found anywhere in the tooth root, but is more common in the apical third of the root. Synonym: lateral canal. (05 Mar 2000) |
| adductor canal | The space in middle third of the thigh between the vastus medialis and adductor muscles, converted into a canal by the overlying sartorius muscle. It gives passage to the femoral vessels and saphenous nerve, ending at the adductor hiatus. Synonym: canalis adductorius, Hunter's canal, subsartorial canal. (05 Mar 2000) |
| Alcock's canal | The space within the obturator internis fascia lining the lateral wall of the ischiorectal fossa that transmits the pudendal vessels and nerves. Synonym: canalis pudendalis, Alcock's canal. (05 Mar 2000) |
| alimentary canal | <anatomy> The digestive tract. (27 Sep 1997) |
| anal canal | The terminal portion of the alimentary canal; it extends from the pelvic diaphragm to the anal orifice. Synonym: canalis analis. (05 Mar 2000) |
| anterior condyloid canal of occipital bone | The canal through which the hypoglossal nerve emerges from the skull. Synonym: canalis hypoglossalis, anterior condyloid canal of occipital bone, anterior condyloid foramen. (05 Mar 2000) |
| archenteric canal | Invagination of the blastopore into the notochordal process to form a cavity. See: neurenteric canal. Synonym: notochordal canal. (05 Mar 2000) |
| Arnold's canal | <anatomy, nerve> The small opening in the petrous bone lateral to the hiatus of facial canal that gives passage to the lesser petrosal nerve. Synonym: hiatus canalis nervi petrosi minoris, Arnold's canal, canalis nervi petrosi superficialis minoris. (05 Mar 2000) |
| arterial canal | Before birth, the blood headed from the heart (via the pulmonary artery) for the lungs is shunted away from the lungs and returned to the greatest of arteries (the aorta). The shunt is through a short vessel called the ductus arteriosus. When the shunt is open, it is said to be patent (pronounced pa'tent). The patent ductus arteriosus (PDA) usually closes at or shortly after birth and blood is permtted from that moment on to course freely to the lungs. If the ductus stays open (patent), flow reverses and blood from the aorta is shunted into the pulmonary artery and recirculated through the lungs. The PDA may close later spontaneously (on its own) or need to be ligated (tied off) surgically. (12 Dec 1998) |