| closed system | <biology, ecology> A chemical or biological system that exchanges no matter or energy with the ouside environment. (12 Mar 1998) |
|---|---|
| covalently closed circular DNA | <molecular biology> A circular molecule of double-stranded DNA which is supercoiled, or coiled up on itself due to internal tensions, because there are no breaks in the phosphate backbone (upon which the nucleotide bases are mounted) to relieve the tensions and allow it to form an open circle. (09 Oct 1997) |
| head injuries, closed | Organic or functional damage resulting from trauma to the head where continuity of the scalp and mucous membranes is maintained. When brain injury results from closed head injuries, the primary cause is mechanical stretching and shearing of nerve fibres. Also common are focal intracranial lesions including haematomas and contusions. (12 Dec 1998) |
| semi-closed anaesthesia | Inhalation anaesthesia using a circuit in which a portion of the exhaled air is exhausted from the circuit and a portion is rebreathed following absorption of carbon dioxide. (05 Mar 2000) |
| semi-closed circle | A circuit for administration of an inhalation anaesthetic in which partial rebreathing with carbon dioxide absorption is combined with loss from the circuit of a portion of respired gases through valves. (05 Mar 2000) |
| ecological systems, closed | Systems that provide for the maintenance of life in an isolated living chamber through reutilization of the material available, in particular, by means of a cycle wherein exhaled carbon dioxide, urine, and other waste matter are converted chemically or by photosynthesis into oxygen, water, and food. (12 Dec 1998) |
| fractures, closed | Fractures in which the break in bone is not accompanied by an external wound. (12 Dec 1998) |
| base of skull | The sloping floor of the cranial cavity. It comprises both the external base of skull (external view) and the internal base of skull (internal view). See: internal base of skull. Synonym: basis cranii, cranial base. (05 Mar 2000) |
| bones of skull | The paired inferior nasal concha, lacrimal, maxilla, nasal, palatine, parietal, temporal, and zygomatic; and the unpaired ethmoid, frontal, occipital, sphenoid, and vomer. Synonym: ossa cranii, cranial bones. (05 Mar 2000) |
| maplike skull | Various defects in the skull, especially in the temporal bone, the anterior fossa, and orbits, forming irregular outlines resembling the national boundaries in an atlas. (05 Mar 2000) |
| roof of skull | <anatomy> The skull cap, roof of the skull (27 Sep 1997) |
| cloverleaf skull | <syndrome> Intrauterine bone dysplasia and synostosis of the coronal and lambdoid sutures producing a trilobar head shape, due to premature fusion (craniosynostosis) of all sutures. This produces various craniofacial and long-bone anomalies. The condition is sporadic; no evidence to suggest a genetic cause although there may be some hereditary in Crouzon syndrome. (20 Jun 2000) |
| cloverleaf skull syndrome | <syndrome> Intrauterine bone dysplasia and synostosis of the coronal and lambdoid sutures producing a trilobar head shape, due to premature fusion (craniosynostosis) of all sutures. This produces various craniofacial and long-bone anomalies. The condition is sporadic; no evidence to suggest a genetic cause although there may be some hereditary in Crouzon syndrome. (20 Jun 2000) |
| single lucent skull lesion | <radiology> Mnemonic: HELP ME, haemangioma, epidermoid / dermoid, leptomeningeal cyst, lambdoid suture defect, Paget's (osteoporosis circumscripta), post-surgical, metastasis (solitary), eosinophilic granuloma, encephalocele (12 Dec 1998) |
| skull | A school, company, or shoal. "A knavish skull of boys and girls did pelt at him." "These fishes enter in great flotes and skulls." (Holland) See: School a multitude. 1. <anatomy> The skeleton of the head of a vertebrate animal, including the brain case, or cranium, and the bones and cartilages of the face and mouth. In many fishes the skull is almost wholly cartilaginous but in the higher vertebrates it is more or less completely ossified, several bones are developed in the face, and the cranium is made up, wholly or partially, of bony plates arranged in three segments, the frontal, parietal, and occipital, and usually closely united in the adult. 2. The head or brain; the seat of intelligence; mind. "Skulls that can not teach, and will not learn." (Cowper) 3. A covering for the head; a skullcap. "Let me put on my skull first." (Beau & Fl) 4. A sort of oar. See Scull. Skull and crossbones, a symbol of death. See Crossbones. Origin: OE. Skulle, sculle, scolle; akin to Scot. Skull, skoll, a bowl, Sw. Skalle skull, skal a shell, and E. Scale; cf. G. Hirnschale, Dan. Hierneskal. Cf. Scale of a balance. Source: Websters Dictionary (01 Mar 1998) |