| sheath process of sphenoid bone | A thin lamina of bone that extends medially under the body of the sphenoid bone from the medial lamina of the pterygoid process; it articulates with the vomer and the palatine bone. Synonym: processus vaginalis ossis sphenoidalis, sheath process of sphenoid bone. (05 Mar 2000) |
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| shin bone | <anatomy> The large bone between the knee and foot that supports 5/6 of the body weight (fibula supports 1/6). (27 Sep 1997) |
| shin bone fever | A louse-borne disease first recognised in the trenches of world war i, again a major problem in the military in world war II, seen endemically in mexico, n. Africa, e, europe, and elsewhere. The cause, rochalimaea quintana, is an unusual rickettsia that multiplies in the gut of the body louse. Transmission to people can occur by rubbing infected louse feces into abraded (scuffed) skin or conjunctiva (whites of the eyes). Onset of symptoms is sudden, with high fever, headache, back and leg pain and a fleeting rash. Recovery takes a month or more. Relapses are common. Also called trench fever, wolhynia fever, quintan fever, five-day fever, meuse fever, his' disease, his-werner disease, werner-his disease. (12 Dec 1998) |
| short bone | One whose dimensions are approximately equal; it consists of a layer of cortical substance enclosing spongy substance and narrow. Compare: long bone. Synonym: os breve. (05 Mar 2000) |
| hyoid bone | <anatomy> A U-shaped bone lying between the mandible and the larynx, suspended from the styloid processes by slender stylohyoid ligaments. See: hyoid apparatus. Synonym: os hyoideum, lingual bone, tongue bone. (05 Mar 2000) |
| sickle cell anaemia: bone manifestations | <radiology> 8-13% of blacks carry sickling factor, symptoms: chronic ulcers, pain crises, many infections, priapism X-ray findings: deossification due to marrow hyperplasia, decreased bone density in skull with widened diploe, H-shaped vertebrae or fish vertebrae, rib notching, thrombosis and infarction, avascular necrosis, especially femoral head, periosteal treatmentn (bone within bone), secondary osteomyelitis, Staph. Aureus greater than Salmonella, dactylitis = hand foot syndrome, growth effects, bone shortening secondary to diminished blood supply, death less than 40y (12 Dec 1998) |
| sieve bone | A horizontal lamina from which are suspended the labyrinth, on either side, and the lamina perpendicularis in the centre; it fits into the ethmoidal notch of the frontal bone and supports the olfactory lobes of the cerebrum, being pierced with numerous openings for the passage of the olfactory nerves. Synonym: lamina cribrosa ossis ethmoidalis, cribrum, sieve bone, sieve plate. (05 Mar 2000) |
| simple bone cyst | <radiology> Unicameral or solitary bone cyst, lytic, unilocular, central, meta-diaphyseal, humerus (most common site), age 0 - 10 yrs Differential diagnosis: bubbly bone lesions (12 Dec 1998) |
| solitary bone cyst | A unilocular cyst containing serous fluid and lined with a thin layer of connective tissue, occurring usually in the shaft of a long bone in a child. Synonym: idiopathic bone cavity, osteocystoma, simple bone cyst, traumatic bone cyst, unicameral bone cyst. (05 Mar 2000) |
| sphenoidal angle of parietal bone | The anterior inferior angle of the parietal bone. Synonym: angulus sphenoidalis ossis parietalis, sphenoid angle, sphenoidal angle, Welcker's angle. (05 Mar 2000) |
| sphenoidal border of temporal bone | The part of the border of the squamous part of the temporal bone that articulates with the greater wing of the sphenoid. Synonym: margo sphenoidalis ossis temporalis. (05 Mar 2000) |
| sphenoid bone | A bone of most irregular shape occupying the base of the skull; it is described as consisting of a central portion, or body, and six processes: two greater wings, two lesser wings and two pterygoid processes; it articulates with the occipital, frontal, ethmoid, and vomer, and with the paired temporal, parietal, zygomatic, palatine and sphenoidal concha bones. Synonym: os sphenoidale, sphenoid. (05 Mar 2000) |
| sphenoid process of palatine bone | The posterior and smaller of the two processes at the extremity of the vertical plate of the palatine bone; processus sphenoidalis cartilaginis septi nasi, processus posterior cartilaginis septi nasi. Synonym: processus sphenoidalis, sphenoid process. (05 Mar 2000) |
| splint bone | The second or fourth, or internal or external small metacarpal bone's in the horse; these are splinter-like in shape and lie on either side of the metacarpal or cannon bone. Synonym: fibula. (05 Mar 2000) |
| spongy bone | A turbinated bone. (05 Mar 2000) |