Primordial male germ cell. See Oocytes, Spermatoza
Author Archives: Brian Hopkins
Specificity (epidemiology)
No definition. See Developmental screening, indices of efficacy, Likelihood ratio (LR), Sensitivity (epidemiology)
Specific nominals
Words used as proper names. See General nominals, Nominal group
Specific language impairment (SLI)
Also known as specific developmental disorder of language, it refers to disorders in language ability that appear in children who seem to be otherwise developing normally and who do not suffer from neurological or sensory impairments, mental retardation, or environmental deprivation . See Disorder, Developmental disorder, Impairment
Species
A taxonomic category of living forms that are phenotypically similar based upon reproductive isolation under natural conditions from other populations, and capable of interbreeding and producing fertile offspring. This is the biospecies concept. As such, it fails to take account of a historical perspective that species are genealogically unique. This, and other problems, means that …
Speciation
The emergence of a new species over geological time such that descendants and ancestors can no longer interbreed. There are three main types of speciation: 1. Allopatric speciation Speciation takes place in small, satellite groups isolated on the peripheries of the species’s range by geographical barriers and subjected to genetic drift 2. Sympatric speciation Speciation …
Special gift
éThe idea, found in René Descartes (1596-1650), as well as in many other traditional sources, that language, as a unique possession of the human species, clearly separates humans from other animals. A controversial doctrine that is disputed by those who claim to have found evidence of language use in the great apes, and especially the pygmy …
Spasticity
Increased resistance to muscle stretch, which is velocity-dependent, and may in part be due to peripheral changes in muscle stiffness. Resistance can suddenly diminish (the ‚aaclasp-knife‚aa effect). Tendon reflexes are hyperactive and clonus may be present. Spasticity is classified according to its distribution across body parts or topographical location. The relationship of spasticity to disordered …
Spatial reasoning
Cognition, reasoning, and problem solving having to do with spatial matters. This is often contrasted to verbal skills. For example, spatial reasoning is needed to insert 3-dimensional forms into openings of different shapes. See Reasoning (psychology), Ventral visual pathway (or stream)
Spastic quadriplegia
Spasticity of all four limbs, the upper limbs being affected equally to, or more than, the lower limbs . See Cerebral palsy, Hydrocephalus, Spasticity