Covering a distance of 20-40 nanometers. See Boutons, Neuromuscular junction, Neurotransmitters, Synapse
Author Archives: Brian Hopkins
Synapse elimination
The patterned reduction in the number of functional connections among nerve cells or between multiple neurons and muscles that occurs as a normal process of neural development following neural proliferation. In early development, there are many more synaptic connections than at maturity and the process of elimination (involving the loss of up to 50% of …
Synapse
Contact site between axon and nerve cell, with chemical transmission of information across the synaptic cleft from the axon of a presynaptic neurone to the axon, dendrite or cell body of a postsynaptic neurone (or sometimes from one dendrite to another). There are two main types of synapses: axodendritic synapses between one axon and the …
Sympathy
Emotional concern for another’s well being. See Autism, Theory of the child’s mind (ToM)
Symmetry breaking (and preservation)
The concept of symmetry in physics refers to the set of invariances of a system that is preserved when some operation is performed on the system. For example, a square rotated by 90aa is indistinguishable from the original and has symmetry under rotation. This is symmetry preservation or the maintenance of a particular invariance between …
Sympathetic nervous system (SNS)
The branch of the autonomic nervous system that plays the major role in an activated state or stress response, and associated with, for example, increased heart rate, dilated pupils, higher blood pressure, and inhibited digestive processes. See Autonomic nervous system (ANS), Catecholamines, Central nervous system (CNS), Cholinergic neurotransmitter system, Epinephrine (or adrenaline), Nerve Growth Factor …
Symbols
A type of signifier or representational vehicle. In Piagetian theory, symbols include such representations as images, pictures, gestures and the use of objects or movements to represent meanings. In contrast to signs (words), symbolic meanings are more personal, less generative, and are more likely to resemble their referents in some way. See Collective agency, Communication, …
Symbolic function
The ability of words to pick out a variety of non-present referents, without actually drawing pictures of these referents. See Symbols
Sylvian fissure
In the human fetes, the sylvan fissure is formed in the course of the third month of gestation.
Syllables
Words can be composed of one or more syllables. Syllables are composed of a central vowel nucleus optionally preceded by a consonant cluster onset and optionally followed by a consonantal offset or coda. See Phonics, Syllabic structure, Syllable-final position, Syllable-initial position