| SM | Master of Science; sadomasochism; self-monitoring; silicon microphysiometer; simple mastectomy; skim... |
|---|---|
| SMA | sequential multiple analysis or analyzer; sequential multichannel autoanalyzer; simultaneous multich... |
| SMABF | superior mesenteric artery blood flow |
| SMAE | superior mesenteric artery embolism |
| SMAO | superior mesenteric artery occlusion |
| sinus posterior | A deep groove above the pyramidal eminence extending to the incudal fossa in the posterior wall of the tympanic cavity. (05 Mar 2000) |
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| sinus prostaticus | The groove on either side of the urethral crest in the prostatic part of the urethra into which the prostatic ducts open. Synonym: sinus prostaticus. (05 Mar 2000) |
| sinus rectus | straight sinus |
| sinus reflex | See: carotid sinus syndrome. (05 Mar 2000) |
| sinus renalis | The cavity of the kidney, containing the calyces and pelvis of the ureter and the segmental vesels embedded within a fatty matrix. The renal sinuses cause the kidneys to appear hollow or C-shaped on cross section or medical imaging. Synonym: sinus renalis. (05 Mar 2000) |
| sinus reuniens | An obsolete term for sinus venosus. Rhomboidal sinus Sinus rhomboidalis, a dilation of the central canal of the spinal cord in the lumbar region. Synonym: rhombocele. (05 Mar 2000) |
| sinus rhythm | The normal regular cardiac rhythm stimulated by the sinoatrial node. (27 Sep 1997) |
| sinus septum | A small fold forming the medial end of the valve of the inferior vena cava; it is developed from the dorsal wall of the embryonic sinus venosus. (05 Mar 2000) |
| sinus sigmoideus | The S-shaped dural venous sinus lying deep to the mastoid process of the temporal bone and immediately posterior to the petrous temporal bone; it is continuous with the transverse sinus and empties into the internal jugular vein as it passes through the jugular foramen. Synonym: sinus sigmoideus. (05 Mar 2000) |
| sinus sphenoidalis | One of a pair of paranasal sinuses in the body of the sphenoid bone communicating with the upper posterior nasal cavity or spenoethmoidal recess. Synonym: sinus sphenoidalis. (05 Mar 2000) |
| sinus sphenoparietalis | A paired dural venous sinus beginning on the parietal bone, running along the sphenoidal ridges and emptying into the cavernous sinus. Synonym: sinus sphenoparietalis, Breschet's sinus, sinus alae parvae. (05 Mar 2000) |
| sinus standstill | Cessation of sinus node activity, marked by absence of normal P waves in the electrocardiogram. Ventricular standstill, cessation of ventricular contractions, marked by absence of ventricular complexes in the electrocardiogram. (05 Mar 2000) |
| sinus tachycardia | A fast heartbeat (tachycardia) occurring because of rapid firing by the sa node, the natural pacemaker of the heart. Electrical signals initiated in the sa node are transmitted to the atria and the ventricles to stimulate heart muscle contractions heartbeats. Sinus tachycardia is usually a rapid contraction of a normal heart in response to a condition, drug, or disease as, for examples, pain, fever, excessive thyroid hormone, exertion, excitement, low blood oxygen level (hypoxia), or stimulant drugs such as caffeine, cocaine, and amphetamines. However, in some cases, it can be a sign of heart failure, heart valve disease, or other illness. (12 Dec 1998) |
| sinus tarsi | tarsal sinus |
| sinus thrombosis | Formation of a clot in a cerebral venous sinus. (12 Dec 1998) |