synapsis(redirected from synaptic phase)
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the pairing off and union of homologous chromosomes from male and female pronuclei at the start of meiosis.
The point-for-point pairing of homologous chromosomes during the prophase of meiosis.
Synonym(s): synaptic phase
[G. a connection, junction]
n. pl. synap·ses (-sēz)
The side-by-side association of homologous chromosomes during the first prophase of meiosis.
The functional membrane-to-membrane contact of the nerve cell with another nerve cell, an effector (muscle, gland) cell, or a sensory receptor cell. The synapse subserves the transmission of nerve impulses, commonly from a club-shaped axon terminal (the presynaptic element) to the circumscript patch of the plasma membrane of the receiving cell (the postsynaptic element) on which the synapse occurs. In most cases, the impulse is transmitted by means of a chemical transmitter substance (such as acetylcholine, gamma-aminobutyric acid, dopamine, norepinephrine) released into a synaptic cleft that separates the presynaptic from the postsynaptic membrane; the transmitter is stored in synaptic vesicles in the presynaptic element. In other synapses, transmission takes place by direct propagation of the bioelectrical potential from the presynaptic to the postsynaptic membrane.
[syn- + G. hapto, to clasp]