Varicosity

Surface tension is also responsible for the varicose or Rayleigh breakup of Hquid strands into droplets. By virtue of surface tension the pressure within a strand is slightly higher than that in the ambient gas by the amount ... 

Ader knoten, kropf, m. varicose vein, varix. 

Krampe,/. cramp, cramp iron staple clip. Krampf, m. cramp, spasm, convulsion, -ader,/. varicose vein. 

Purinergic System. Figure 2 Schematic of sympathetic cotransmission. ATP and NA released from small granular vesicles (SGV) act on P2X and a-i receptors on smooth muscle, respectively. ATP acting on inotropic P2X receptors evokes excitatory junction potentials (EJPs), increase in intracellular calcium ([Ca2+]j) and fast contraction while occupation of metabotropic ar-adrenoceptors leads to production of inositol triphosphate (IP3), increase in [Ca2+]j and slow contraction. Neuropeptide Y (NPY) stored in large granular vesicles (LGV) acts after release both as a prejunctional inhibitory modulator of release of ATP and NA and as a postjunctional modulatory potentiator of the actions of ATP and NA. Soluble nucleotidases are released from nerve varicosities, and are also present as ectonucleotidases. (Reproduced from Burnstock G (2007) Neurotransmission, neuromodulation cotransmission. In Squire LR (ed) New encyclopaedia of neuroscience. Elsevier, The Netherlands (In Press), with permission from Elsevier). 

Bill berry Vaccinium myrtiiius Vision enhancement and eye health, microcirculation, spider veins and varicose veins, capillary strengthening before surgery No adverse effects have been reported in clinical studies. None significant. 

Figure 4. Neurite outgrowth by LA-N-1 human neuroblastoma cells in culture. LA-N-1 human PNS neuroblastoma cells were grown for five days in N2 medium (as described by Bottenstein and Sato, 1979) on a polylysine and fibronectin-modified surface. The cells were plated in clumps, rather than as a single cell suspension, which enhances neurite extension. Very long processes result, and exhibit varicosities along their length. Most of the cells have migrated from the central clump. (Photo courtesy of Dr. jane Bottenstein.)...

In smooth muscle, by contrast, one sympathetic nerve fibre can influence a number of muscle fibres by releasing noradrenaline from varicosities along its length without there being any defined end-plate junctions. The result of receptor activation is a slow change in potential and inactivation of the NT is initially by uptake and then metabolism. In other words, the NT function is geared to the slower phasic changes in tone characteristic of smooth muscle. 

Figure 4.10 An electron micrograph of a terminal varicosity containing a large dense-core vesicle (LDCV), indicated by the arrow and many small synaptic vesicles (SSVs), some of which contain an electron dense core. Calibration mark 250 nM. (Figure kindly supplied by M. Fillenz)...

Basbaum, CB and Heuser, JE (1979) Morphological studies of stimulated adrenergic axon varicosities in the mouse vas deferens. J. Cell Biol. 80 310-325. 

In that and subsequent studies (Kosofsky 1985 Blue et al. 1988a), a distinct laminar pattern of innervation was found in somatosensory cortex, and a quite different pattern in the cingulate cortex, hippocampus, and dentate gyrus, where there are distinct bands of highly varicose axons. In the primate, the 5-HT innervation of cerebral cortex is denser and more highly differentiated among different architectonic and functional areas (Kosofsky et al. 1984 Morrison et al. 1982 Morrison and Foote 1986 Wilson and Molliver 1986 Wilson et al. 1989). For example, marked differences in the density and distribution of 5-HT axons are found in the macaque on either side of the central sulcus, in primary motor and somatosensory cortex while... 

NOTE These axons exhibit cytopathologic changes, such as large, swollen varicosities, irregular... 

ANSWER Yes. We have very carefully evaluated that question and Dr. O Hearn is a great skeptic who is forcing us to look at it very closely. We are finding that the large varicosity fibers that are left are identical in distribution, morphology, and density to those present in the normal fibers. The damaged fibers are of a completely different nature they are 10 times... 

Venous stasis Major medical illness (e.g., congestive heart failure) Major surgery (e.g., general anesthesia for greater than 30 minutes) Paralysis (e.g., due to stroke or spinal cord injury) Polycythemia vera Obesity Varicose veins... 

Axon terminal with multiple varicosities releases neurotransmitter over wide surface area affecting many tissue cells Gap junctions allow spread of nervous stimulation throughout tissue... 

Synapses between the autonomic postganglionic neuron and effector tissue — the neuroeffector junction — differ greatly from the neuron-to-neuron synapses discussed previously in Chapter 5 (see Table 9.1). The postganglionic fibers in the ANS do not terminate in a single swelling like the synaptic knob, nor do they synapse directly with the cells of a tissue. Instead, the axon terminals branch and contain multiple swellings called varicosities that lie across the surface of the tissue. When the neuron is stimulated, these varicosities release neurotransmitter over a large surface area of the effector tissue. This diffuse release of the neurotransmitter affects many tissue cells simultaneously. Furthermore, cardiac muscle and most smooth muscle have gap junctions between cells. These specialized intercellular communications... 

Compared to a,-receptors, a2-receptors have only moderate distribution on the effector tissues however, they have important presynaptic effects. Alpha-one receptors are found on effector tissue cells at the neuroeffector junction the a2-receptors are found on the varicosities of the postganglionic neuron. Norepinephrine released from this neuron not only binds to the a.j-receptors on the effector tissue to cause some physiological effect but also binds to the a2-receptors on the neuron. Alpha-two receptor stimulation results in presynaptic inhibition" or in a decrease in the release of norepinephrine. In this way, norepinephrine inhibits its own release from the sympathetic postganglionic neuron and controls its own activity. Both ar and a2-receptors have equal affinity for norepinephrine released directly from sympathetic neurons as well as circulating epinephrine released from the adrenal medulla. 

Autoradiographic studies with [3H]R-(a)-methylhistamine have demonstrated the presence of high to moderate levels of H3 receptor binding in almost all layers of the cerebral cortex, striatum, bed nuclei of the stria terminalis, substantia nigra, amygdala, olfactory nucleus, hippocampus, and hypothalamus, especially on the cell somata, dendrites, and axonal varicosities of HA-containing TMN... 

Varicose ulcers Due to defective circulation, sometimes associated with varicose veins... 

Sesack, S. R.,Hawrylak, V. A., Matus, C., Guido, M. A and Levey, A. I. Dopamine axon varicosities in the prelimbic division of the rat prefrontal cortex exhibit sparse immuno-reactivity for the dopamine transporter. /. Neurosci. 18 2697-2708,1998. 

Thick, non-varicose tract-fibers Short, thin branches Large, round boutons... 

Venous stasis is slowed blood flow in the deep veins of the legs resulting from damage to venous valves, vessel obstruction, prolonged periods of immobility, or increased blood viscosity. Conditions associated with venous stasis include major medical illness (e.g., heart failure, myocardial infarction), major surgery, paralysis (e.g., stroke, spinal cord injury), polycythemia vera, obesity, or varicose veins. 

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