Salivary spending about 0.5 to 1.5 liters per day. Depending on the level of stimulation, the flow rate varies from 0.1 to 4 ml / min. At a rate of 0.5 ml / min approximately 95% of saliva secreted by the parotid gland (salivary watery) and submandibular gland (salivary mucin-rich); the remainder is secreted by glands and sublingual glands in the mucosal lining of the mouth (Despopoulos and Silbernagl, 2000). Spontaneous salivary secretion and continuous, even in the absence of a clear stimulation, caused by low levels of constant stimulation of the parasympathetic nervous endings ending in salivary glands. Basal secretion is important to keep the mouth and throat remain wet all the time (Sherwood, 2001).
In addition to the secretion of which is constant and the little, salivary secretion can be enhanced through two different types of salivary reflex: (1) simple salivary reflex, or unconditioned, and (2) acquired salivary reflex, or unconditioned. Simple salivary reflex (unconditioned) occurs when chemoreceptors or pressure receptors in the oral cavity responds to the presence of food.
When activated, these receptors initiate afferent impulses in nerve fibers that carry information to the salivary center in the medulla of the brain stem. Salivary center then sends impulses through the autonomic nerves extrinsic to the salivary glands to increase the secretion of saliva. Encourage actions tooth salivary secretion although there is no food because of the manipulation of the pressure receptors located in the mouth. At acquired salivary reflex (unconditioned), salivary expenditure occurs without oral stimulation. Just think, see, smell, or hear a delicious meal can trigger the saliva through this reflex (Sherwood, 2001).
Salivary center controls the degree of spending saliva through the autonomic nerves that innervate the salivary glands. Unlike the autonomic nervous system in other places, sympathetic and parasympathetic response in the salivary glands are not mutually contradictory. Both the sympathetic and parasympathetic stimulation, both increasing the secretion of saliva, but the number, characteristics, and the role of different mechanisms. Parasympathetic stimulation, which play a dominant role in the secretion of saliva, causing the expenditure of large amounts of dilute saliva and rich in enzymes. Sympathetic stimulation, on the other hand, the volume of saliva which produces much less with a thick and rich consistency of mucus. Because sympathetic stimulation causes secretion of saliva in small amounts, mouth feels drier than usual over the current state of the sympathetic system is dominant, for example in times of stress (Sherwood, 2001).
Parasympathetic nerve pathways to regulate the expenditure of saliva mainly controlled by the parasympathetic nerve signals along the path of the superior and inferior salivatorius nucleus of the brain stem (Guyton and Hall, 2008). Other objects in the mouth can move the salivary reflex by stimulating receptors that are monitored by the trigeminal nerve (V) or innervation of the tongue is monitored by cranial nerves VII, IX, or X. parasympathetic stimulation will accelerate at all salivary gland secretion, resulting in the production of saliva in large quantities (Martini, 2006; Tortora and Derrickson, 2009)
