| RPO | Right Posterior Oblique view |
|---|---|
| AO | abdominal aorta; achievement orientation; acid output; acridine orange; ankle orthosis; anodal openi... |
| IO | incisal opening; inferior oblique; inferior olive; internal os; interorbital; intestinal obstruction... |
| LAO | left anterior oblique; left atrial overload; Licentiate of the Art of Obstetrics |
| LIO | left inferior oblique |
| Fischer projection formula | <biochemistry> Of sugars, representations, by projection, of cyclic sugars, or derivatives thereof, in which the carbon chain is depicted vertically. The lowest-numbered asymmetric carbon atom (C-1 in aldoses; C-2 in 2-ketoses, e.g., fructose) is drawn at the top, and the rest of the carbon atoms of the chain are drawn in sequence below the top carbon atom. For each carbon atom, depicted in projection as lying in the plane of the paper, the carbon-to-carbon bond(s), which actually point away from the viewer, are drawn as vertical lines. The left-hand and right-hand bonds of each carbon atom, which actually point toward the viewer, are, in projection, depicted as horizontal lines. The conventions for the Fischer formulas of cyclic sugars are as follows: 1) if the highest-numbered asymmetric carbon atom has its OH (or its replacement) lying to the right, as is the 2-OH of d-glyceraldehyde, the sugar has the d configuration; if the OH is to the left, the sugar has the l configuration. 2) On the anomeric carbon atom (C-1 in the aldoses; C-2 in the 2-ketoses), an OH or substituted OH that lies to the right, with the OH of the highest-numbered asymmetric carbon atom also to the right is defined to be a; if it is to the left, with the OH of the highest-numbered carbon atom still to the right, it is b; the reverse applies if the latter OH is to the left. 3) The orientation of a terminal CH2OH group in the aldoses carries no configurational significance, as it contains no asymmetric carbon atom. (05 Mar 2000) |
|---|---|
| lateral projection | Radiographic projection with the X-ray beam in a coronal plane. (05 Mar 2000) |
| frog-leg lateral projection | A lateral projection of the femoral neck made with the thigh maximally abducted. (05 Mar 2000) |
| abdominal external oblique muscle | <anatomy, muscle> Origin, fifth to twelfth ribs; insertion, anterior half of lateral lip of iliac crest, inguinal ligament, and anterior layer of the rectus sheath; action, diminishes capacity of abdomen, draws thorax downward; nerve supply, thoracoabdominal nerves. Synonym: musculus obliquus externus abdominis, abdominal external oblique muscle. (05 Mar 2000) |
| abdominal internal oblique muscle | <anatomy, muscle> Origin, iliac fascia deep to lateral part of inguinal ligament, anterior half of crest of ilium, and lumbar fascia; insertion, tenth to twelfth ribs and sheath of rectus; some of the fibres from inguinal ligament terminate in the conjoint tendon; action, diminishes capacity of abdomen, flexes lumbar vertebral column (bends thorax forward); nerve supply, lower thoracic. Synonym: musculus obliquus internus abdominis, abdominal internal oblique muscle. (05 Mar 2000) |
| aponeurosis of external abdominal oblique muscle | <anatomy> Broad, flat tendinous portion of the external abdominal oblique muscle. The fleshy fibres of the muscle end in the aponeurosis along a line descending vertically from the costochondral joint of the ninth rib then turning laterally just below the level of the umbilicus toward the anterior superior iliac spine. The fibres of the aponeurosis run medially and inferiorly, contributing to the anterior wall of the sheath of the rectus abdominis muscle and decussating with those of the contralateral aponeurosis at the median linea alba. Inferomedially, the aponeurosis is attached to the upper border of the pubic symphysis, the pubic crest and pubic tubercle. Between the anterior superior iliac spine and the pubic tubercle, it is thickened and turned under, forming the inguinal ligaments. The portion of the aponeurosis attached to the pubic bone forms the superficial inguinal ring by splitting into medial and lateral crura. See: external spermatic fascia, inguinal ligament, lacunar ligament, pectineal ligament, reflected inguinal ligament, superficial inguinal ring, rectus sheath. (05 Mar 2000) |
| aponeurosis of internal abdominal oblique muscle | <anatomy> Broad, flat tendinous portion of the internal abdominal oblique muscle. The fleshy fibres of the muscle end in the aponeurosis lateral to the semilunar line. The uppermost portion of the aponeurosis is attached to the outer surfaces and lower borders of the seventh to ninth costal cartilages. Of the portion extending between the costoxiphoid margin and the pubis, the upper two-thirds splits into anterior and posterior laminae at the lateral border of the rectus abdominis muscle to contribute to the anterior and posterior walls of the sheath of the rectus abdominis muscle as they extend to the midline linea alba. The lower third of the aponeurosis does not split but joins the aponeuroses of the external abdominal oblique and transversus abdominis muscles to form the anterior wall of the sheath of the rectus abdominis muscle. The fibres of the portion of the aponeurosis contributing to the rectus sheath decussate with those of the contralateral aponeurosis in the linea alba. The lowermost portion of the aponeurosis blends with the aponeurosis of the transversus abdominis muscle to form the conjoint tendon, attaching to the pubic crest and often the pecten pubis, thus forming the posterior wall of the inguinal canal at the superficial inguinal ring. See: cremasteric fascia, conjoint tendon, rectus sheath. (05 Mar 2000) |
| astigmatism of oblique pencils | An aberration occurring when a bundle of light rays strikes a refracting medium in some other direction than parallel to the axis of the lens. (05 Mar 2000) |
| Marshall's oblique vein | A small vein on the posterior wall of the left atrium which merges with the great cardiac vein to form the coronary sinus; it is developed from the left common cardinal vein, and occasionally persists as a left superior vena cava. Synonym: vena obliqua atrii sinistri, Marshall's oblique vein. (05 Mar 2000) |
| sliding oblique osteotomy | An oral surgical procedure in which the mandibular ramus is cut vertically from the sigmoid notch to the angle to facilitate posterior repositioning of the mandible in correction of mandibular prognathism; it may be performed extraorally or intraorally, and is similar to vertical osteotomy. (05 Mar 2000) |
| superior oblique | <anatomy, muscle> Origin, above the medial margin of the optic canal; insertion, by a tendon passing through the trochlea, or pulley, and then reflected backward, downward, and laterally to the sclera between the superior and lateral recti; action, primary, intorsion; secondary, depression and abduction; nerve supply, trochlear nerve. Synonym: musculus obliquus superior. (05 Mar 2000) |
| superior oblique muscle of head | <anatomy, muscle> Origin, transverse process of atlas; insertion, lateral third of inferior nuchal line; action, rotates head; nerve supply, suboccipital. See: suboccipital muscles. Synonym: musculus obliquus capitis superior, superior oblique muscle of head. (05 Mar 2000) |
| illumination, oblique | <microscopy> Illumination from light inclined at an oblique angle to the optical axis. (05 Aug 1998) |
| inferior oblique | <anatomy, muscle> Origin, orbital plate of maxilla lateral to the lacrimal groove; insertion, sclera between the superior and lateral recti; action, primary, extorsion; secondary, elevation and abduction; nerve supply, oculomotor (inferior branch). Synonym: musculus obliquus inferior. (05 Mar 2000) |
| inferior oblique muscle of head | <anatomy, muscle> Origin, spinous process of axis; insertion, transverse process of the atlas; action, rotates head; origin, spinous process of axis; insertion, transverse process of the atlas; nerve supply, suboccipital. See: suboccipital muscles. Synonym: musculus obliquus capitis inferior, inferior oblique muscle of head. (05 Mar 2000) |