Talk:Physiology

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Should this be reverted? I don't see how a highly technical discussion of urination belongs on such a high-level page. -- Pakaran 02:26, 11 Dec 2003 (UTC)

Not sure where this should go, moving to Talk for the moment. --Lexor 14:07, 15 Jan 2004 (UTC)

Respiration tracheal stenosis is a respiratory problem that narrows the tracheal lumen that can be congenital or acquired. In congenital tracheal stenosis the trachea is very much narrowed due to tracheal cartilages being smaller than normal and to the absence of posterior menbrane. Thus the trachea becomes very rigid. The sequence of events that leads to this kind of stenosis involves the ulceration of the mucosa and cartilag, inflammatory reactions with the grannulation tissue, fibrous tissue formation, and the contarction of the scar tissue. The capillary perfusion pressure is a possible suspect in mucosal injury. Mucosal ischemia is created by direct contact with a segment of the endotracheal tube or an increase in pressure of the tube cuff. It seems that the initially the laryngotracheal ijury was gormed by the endotracheal tube is ulceration itself. The ulcer healing would involve the regeneration of the epithelium. In this process if the healing does not cover the granulation tissue the groth of this tissue would become larger. The tissue itself has two forms: pseudopapillary and nodular granulation. Many weeks and months that pass, the granulation tissue that was initially vascular, becomes somehat of an avascular scar that just contain a few widely separated blood vessels. In the United States alone, 4-13% adults alone have traceal stenosis and in newborns, about 1-8% occurs after prolonged intubation.

Micturition: Reflex is a activated when the urinary bladder wall is stretched and it results in micturition, which is the elimination of urine from the bladder. The micturition occurs in the spinal cord, specifically in the sacral region. That is modified by the higher centers in the brain the pons and cerebrum. It is due to the presence of urine in the bladder stimulates the stretch receptors, which produces action potentional.

The action potentials are carried by sensory neurons to the sacral segments of the spinal cord through the pelvic nerves. the parasympathetic fibers carry the action potentials to the urinary bladder in the pelvic nerves. This causes the wall of the bladder to contract. In addition, decreased somatic motor action potentials cause the external urinary sphincter, which consists of skeletal muscle, to relax. When the external urinary sphincter is relaxed urine will flow from the urinary bladder when the pressure there is great enough to force urine to flow through the urethra. The micturition reflex normally produces a series of contractions of the urinary bladder.

Action potentials carried by sensory neurons from stretch receptors in the urinary bladder wall also ascend the spinal cord to a micturition center in the pons and to the cerebrum. Descending potentials are sent from these areas of the brain to the sacral region of the spinal cord, where they modify the activity of the micturition reflex in the spinal cord. The micturition reflex, integrated in the spinal cord, predominates in infants.

The desire to urinate normally results from stretch of the urinary bladder wall, but irritation of the urinary bladder or the urethra by bacterial infections or other conditions can also initiate the desire to urinate, even though the urinary bladder may be nearly empty.

<<Physiology has several independent subdivisions>>

This is not true. Physiology studies organisms "as a whole". Even there are many "subdivisions" of physiology, made for in deep study, they are not independent. All physiological areas of study are deeply interconnected.

This entire page is not satisfactory. How is neurophysiology an "independant subdivsion" and yet respiratory physiology a "topic"?PhatRita 29 June 2005 22:38 (UTC)