(n.) One of the special jointed organs situated on the under side, and near the end, of the abdomen of spiders, by means of which they spin their webs. Most spiders have three pairs of spinnerets, but some have only two pairs. The ordinary silk line of the spider is composed of numerous smaller lines jointed after issuing from the spinnerets.
Example Sentences:
(1) The proximal region of the gland is capable of protrusion through the prothoracic sternal slit as an elongate organ reaching upto the spinneret.
(2) PC12 cells, an immortalized cell line which secretes large amounts of dopamine, and dissociated bovine adrenal chromaffin cells, a non-dividing cell type which also secretes dopamine, were coextruded by a dry-jet wet spinning technique through a double-lumen spinneret from a 15% weight by volume solution of poly(acrylonitrile vinyl chloride) in either dimethylsulphoxide (DMSO), dimethylacetamide (DMAC) or dimethylformamide (DMF).
(3) Two others, called MoonLightPath and Spinneret, "are planned to be added by September 2013."
(4) The detection of a special mechanoreceptive field on top of the anterolateral spinnerets increases the knowledge of the functional morphology of the spider's spinning apparatus.
(5) They are formed of seven cells: a principal unpaired secretory cell which produces an abundant glycoproteinaceous secretion; a small associated cell with a secondary reservoir for this secretion; two accessory secretory cells which have very abundant tubular extensions coming from the plasma membrane, and a flocculent secretion gathered in a large sub-cuticular space; two cells forming an enlarged part of the excretory canal, functioning like a spinneret; and finally a single cell forming the tubular duct of this complex gland.
(6) The spinnerets of these two animals were also examined by scanning electron microscopy.
Swimmeret
Definition:
(n.) One of a series of flat, fringed, and usually bilobed, appendages, of which several pairs occur on the abdominal somites of many crustaceans. They are used as fins in swimming.
Example Sentences:
(1) Mechanosensory stimulation of an abdominal swimmeret initiates a fictive extension which includes flexion inhibition.
(2) The strongest extension response was produced at 2 Hz which falls within the normal range of swimmeret beating in intact lobsters.
(3) Feathered hair sensilla fringe both rami of the lobster (Homarus americanus) swimmeret.
(4) Proof that PTX acts by binding the GABA receptor was obtained by observing that the addition of GABA or muscimol to preparations pretreated with PTX did not affect either spontaneous or swimmeret evoked activities, or intracellular potential amplitudes.
(5) The sensilla on the male and female second swimmerets are sexually dimorphic.
(6) Evidence from extracellular analyses suggested that single interneurons of the abdominal nerve cord could produce motor outputs in both the swimmeret and the abdominal positioning systems.
(7) Localized tactile stimulation of the swimmeret surface with a mechanical probe usually generated flexion inhibition where the flexor inhibitor (f5) was activated while the small and medium flexor excitors were inhibited.
(8) DL-Octopamine inhibits the swimmeret system, both when the system is spontaneously active and when it has been excited by proctolin.
(9) Physiological experiments in which RPCH was perfused into the ganglia of isolated nerve cords showed that RPCH modulated the swimmeret rhythm.
(10) A study has been made of the interrelations between rhythmical exopodite beating in different larval stages and swimmeret beating in poast-larval stages of the lobster Homarus gammarus.
(11) Female swimmerets contain many long "smooth hairs" (long simple setae) on the coxa and rami.
(12) The membrane potential of interneuron IA oscillated in phase with the swimmeret rhythm, a motor pattern generated in each of these ganglia, because the neuron received postsynaptic potentials in phase with the rhythm.
(13) Differences emerge in the performance of larval exopodites and post-larval swimmerets (table 6b), although the possibility cannot be excluded that the larval exopodite oscillator in some way influences the developing action of the post-larval swimmeret system.
(14) The response properties of both types of hypodermal mechanoreceptors imply that they are activated during the characteristic beating movements of the swimmerets.
(15) The swimmerets in the abdomen of the lobster Homarus americanus are paired external appendages whose back and forth propulsive movements are brought about largely by a group of power and return stroke muscles located in the lateral abdominal cavity.
(16) None of the dual output neurons examined influenced the swimmeret motoneurons directly.
(17) Gas chromatographic analysis of hepatopancreas and swimmeret muscle tissue of dead and dying crabs revealed total DDT residue concentrations as high as 39.0 ppm and 1.43 ppm, respectively.
(18) Phentolamine also blocks inhibition of the swimmeret system by inhibitory command interneurons.
(19) The sensory response to hair displacement was characterized by recording afferent impulses extracellularly from the swimmeret sensory nerve while deflecting sensilla with a rigidly-coupled probe or controlled water movements.
(20) In nerve cords that were spontaneously producing the swimmeret rhythm, RPCH lengthened both the period and the duration of bursts of action potentials, but did not alter the phase relationships between bursts in different segments.