| sella | 1. A seat for a rider, usually made of leather, padded to span comfortably a horse's back, furnished with stirrups for the rider's feet to rest in, and fastened in place with a girth; also, a seat for the rider on a bicycle or tricycle. 2. A padded part of a harness which is worn on a horse's back, being fastened in place with a girth. It serves various purposes, as to keep the breeching in place, carry guides for the reins, etc. 3. A piece of meat containing a part of the backbone of an animal with the ribs on each side; as, a saddle of mutton, of venison, etc. 4. A block of wood, usually fastened to some spar, and shaped to receive the end of another spar. 5. <machinery> A part, as a flange, which is hollowed out to fit upon a convex surface and serve as a means of attachment or support. 6. <zoology> The clitellus of an earthworm. 7. The threshold of a door, when a separate piece from the floor or landing; so called because it spans and covers the joint between two floors. <medicine> Saddle bar, any thin plicated bivalve shaell of the genera Placuna and Anomia; so called from its shape. Synonym: saddle oyster. Origin: OE. Sadel, AS. Sadol; akin to D. Zadel, G. Sattel, OHG. Satal, satul, Icel. Sothull, Dan. & Sw. Sadel; cf. Russ. Siedlo; all perh. Ultimately from the root of E. Sit. Source: Websters Dictionary (01 Mar 1998) |
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| sella turcica | <anatomy> A transverse depression crossing the midline on the superior surface of the body of the sphenoid bone and containing the pituitary gland. It is named "turkish saddle" from its resemblance to the saddle used by turks. (12 Dec 1998) |
| sellar | Relating to the sella turcica. (05 Mar 2000) |
| diaphragm of sella | A fold of dura mater extending transversely across the sella turcica and roofing over the hypophyseal fossa; it is perforated in its centre for the passage of the infundibulum. Synonym: diaphragma sellae, diaphragm sellae, tentorium of hypophysis. (05 Mar 2000) |
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| empty sella | A sella turcica, often enlarged, that contains no discernible pituitary gland; may be primarily due to an incompetent sellar diaphragm with compression of the pituitary gland by herniating arachnoid or secondarily due to surgery or radiotherapy. (05 Mar 2000) |
| empty sella syndrome | <radiology> Aetiology, idiopathic, most commonly reported in middle-aged obese women (associated with DM, hypertension, normal pituitary function), secondary, pituitary adenoma, surgery or irradiation, communicating hydrocephalus, familial (very rare) X-ray findings: sella normal or increased, intrasellar herniation of subarachnoid space, symptoms: headache, visual disorders, with or without decreased pituitary function, cerebrospinal fluid rhinorrhoea (12 Dec 1998) |
| J-sella deformity | Pear-shaped or J-shaped deformity of sella turcica caused by increased pressure on growing sphenoid bone; noted in the mucopolysaccharide storage diseases. (05 Mar 2000) |
| j-shaped sella | <radiology> Cretinism (hypothyroidism), optic glioma, neurofibromatosis, Hurler syndrome (MPS I), mild arrested hydrocephalus, normal variant (12 Dec 1998) |