Neutral reflex

An important gastric secretion is the hydrochloric acid that performs a number of functions in the stomach. This stomach acid is neutralized by pancreatic bicarbonate ion in the duodenum. Excess acid in the chyme stimulates chemoreceptors in the duodenum. This receptor stimulation elicits reflex inhibition of gastric motility. Excess acid also causes the release of secretin and gastric inhibitory peptide from the duodenum. These hormones contribute to inhibition of gastric contractions so that the neutralization process may be completed before additional acid arrives in chyme from the stomach. 

Therapeutically, dilute ammonia solution is used as a reflex stimulant in smelling salts , as a rubefacient, and as a counterirritant to neutralize insect bites or stings. ... 

It forms two series of salts with bases—acid salts, which have a coppery reflex, and neutral salts, which are colourless. The acid sodium salt is a commercial product, and is known as water blue for silk."... 

Haitnup Disease 1 4a. Type I (kidney 4- gut) ( 4b. Type II (kidney) f (recessive) Neutral monoamino, mono-carboxylic acids (except imino adds, methionine and ar nine) Neutral amino adds (atmormal urinary indole pattern due to bacteria] tamv on of tryptophan) Mental retardation and psychosis, episodic cerebellar ataxia, pellagraUke sjmaptoins and abnormal plantar reflex (nicotinamide therapy) Chromatography shows increase of urinary monoamino, mono-carboxyHc adds (B2, B20, E5. E12. H17, H18, H19, J5. M8. M8, P12, R9.T3a... 

Lustrous sqnare pyramids (dark red with green reflex) from petr ether, rap 151-152°. Almost insol in water. Moderately sol in alcohol, ether freely sol in chloroform, tuomofonn, benzene. Alkaline or neutral solns are orange -yellow, acid solns are red. Absorption max (isopropanol) 466 nra (e 43000) 336, 280 nm. 

FIG. 6-4 (A) Neutral position. (B) Stretch of extrafusal and intrafusal alpha motor neuron stimulated to reflexively initiate extrafusal muscle contraction. (C) Gamma motor neuron innervation of muscle spindle. Contraction of ends stretches spindle, activating lb fibers, lb sensory fiber activates alpha motor neuron to cause extrafusal muscle contraction. (D) Compression of whole muscle or contraction of extrafusal muscle results in shortening of muscle spindle and deactivation of sensory fiber firing. 

The patient is supine with the head in neutral position. A pillow is placed across the shoulders to allow the head to be slightly hyper-extended. This facilitates the recognition of the thyroid and the cricoid cartilages. The skin covering the space between the thyroid and the cricoid cartilage is anesthetized with 1% xylocaine. This permits the patient to feel less pain which in turn decreases the tension in the patient and the tendency to evoke the swallowing reflex. For purposes of introducing the electrode, the patient s larynx should be steady. 

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