Distal Ganglia

In the primitive nervous system, sensory cells evolved from general epithelial cells. Primitive nervous systems of modern echinoderms and lower deuterostomes are still composed of three cell types that include the primary sensory cells, the neurons that connect the sensory cells to distal targets, and a supporting cell that serves the special physiological needs of such a system (Lacalli, 2001). The basic structural plan of the retina is comparable to such a primitive nervous system. In the course of evolution, the photoreceptive system developed specialized photoreceptor cells (rods and cones), intra-retinal second-order neurons (bipolar cells), and tertiary output neurons (ganglion cells). This evolution perhaps took place in photopic conditions therefore early photoreceptor cells were more like cones. 

ENT (OCT 3) Epi NE >DA Liver Brain Heart Blood vessels Kidney Placenta Retina Hepatocytes Glial cells, others Myocytes Endothelial cells Cortex, proximal and distal tubules S y ncytiotrophoblast (basal membrane) Photoreceptors, ganglion amacrine cells Isocyanines, corticosterone, 0-methyl- isoproterenol... 

The strain index has not been developed to predict increased risk for distal upper-extremity disorders to uncertain etiology or relationship to work. Examples include ganglion cysts, osteoarthritis, avascular necrosis of carpal bones, and ulnar nerve entrapment at the elbow. 

The potential for maturational changes in the sensitivity of a putative O2 sensor does not, of course, exclude the possibility of other maturational changes occurring at sites more distal to the sensor. Indeed, a significant body of evidence has been gathered to demonstrate a postnatal elevation in catecholamine, specifically dopamine, mRNA levels in carotid body and pelrosal ganglion tissue (86,87). Additionally, the amount of catecholamine released with hypoxia (88,89) but not with elevated extracellular K concentration (89) increases with postnatal age. 

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