| spontaneous pneumothorax | A sudden collapse of the lung that occurs as the result of a tear in the lung tissue. May be seen after strenuous activity, coughing or straining. Thin males are at greatest risk for this disorder. (27 Sep 1997) |
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| spontaneous process | <chemistry> A process that occurs without outside intervention. Spontaneity is independent of rate. To be spontaneous a process must increase the entropy of the universe. (09 Jan 1998) |
| spontaneous recovery | The return of the conditioned response, after apparent extinction, in the presence of the conditioned stimulus without the unconditioned stimulus also being present. See: classical conditioning. (05 Mar 2000) |
| spontaneous transformation | Transformation of a cultured cell that occurs without the deliberate addition of a transforming agent. Cells from some species, especially rodents, are particularly prone to such spontaneous transformation. (18 Nov 1997) |
| spontaneous version | Turning of the foetus effected by the unaided contraction of the uterine muscle. (05 Mar 2000) |
| Denman's spontaneous evolution | A mechanism of spontaneous molding of the foetus and impaction of the shoulder with prolapse of the arm noted in some cases of transverse lie; vaginal delivery is achieved with the breech appearing at the vulva immediately after the prolapsed shoulder. (05 Mar 2000) |
| Douglas' spontaneous evolution | A mechanism whereby molding of the foetus and impaction of the shoulder and prolapsed arm occurs in transverse lie, allowing vaginal delivery with the lateral aspect of the thorax following the prolapsed shoulder. (05 Mar 2000) |
| otoacoustic emissions, spontaneous | Sinusoidal tones originating in the cochlea. These faint sounds, with levels between 10-30 decibels, are usually not recognised by the persons having them. However, the emissions can be recorded using sensitive microphones placed in the ear canals. The clinical significance of having or not having spontaneous otoacoustic emissions is unclear; however, some association between tinnitus and the spontaneous emissions has been reported. (12 Dec 1998) |
| fractures, spontaneous | Fractures occurring as a result of disease of a bone or from some undiscoverable cause, and not due to trauma. (12 Dec 1998) |