Digestion in oral cavity

Common characteristic of the mouth cavity digestion In the oral cavity take place such main processes: In the oral cavity take place such main processes: 1. Primary analyses of substances, which are coming to organism – taste analyzes; 1. Primary analyses of substances, which are coming to organism – taste analyzes; 2. Reflector signals from receptor, which are present in these area to the another organs of digestive system, to the central nerve system – medulla oblongata, stomach, small intestine, pancreas; 2. Reflector signals from receptor, which are present in these area to the another organs of digestive system, to the central nerve system – medulla oblongata, stomach, small intestine, pancreas; 3. Chemical processing of food; 3. Chemical processing of food; 4. Mechanical processing of food; 4. Mechanical processing of food; 5. Absorption of some substances. 5. Absorption of some substances.

Chewing of food is important, because fruits and vegetables have cellulose which must be broken before the food can be utilized. In the mouth cavity begin digestion of carbohydrates, which help to the functional activity of pancreas. Chewing of food is important, because fruits and vegetables have cellulose which must be broken before the food can be utilized. In the mouth cavity begin digestion of carbohydrates, which help to the functional activity of pancreas.

When our food are in the mouth stimulate the receptors of oral cavity; from which impulses go to the different part of brain and return to different part of digestion tract – stomach, small intestine, pancreas, in which secreted juices with enzymes When our food are in the mouth stimulate the receptors of oral cavity; from which impulses go to the different part of brain and return to different part of digestion tract – stomach, small intestine, pancreas, in which secreted juices with enzymes

In the mouth cavity open three pair of big salivary glands and a lot of small buccal glands. Submandibular and sublingual glands consist of the cells of serum and mucous types and secrete serous and mucus types of saliva. Parotid glands consist of the serum types cells and secrete serous type of saliva. In the mouth cavity open three pair of big salivary glands and a lot of small buccal glands. Submandibular and sublingual glands consist of the cells of serum and mucous types and secrete serous and mucus types of saliva. Parotid glands consist of the serum types cells and secrete serous type of saliva.

Small buccal glands consist of mucous types of cells; produce mucous saliva with a big quantity of water. Saliva necessary for our digestion. In a mouth chewing a food by teeth and lingual. In the mouth cavity begin digestion of carbohydrates by alfa-amilase – ptyalin. To secrete different types of saliva for digestion processes – with a big quantity of water or organic and inorganic substances. Small buccal glands consist of mucous types of cells; produce mucous saliva with a big quantity of water. Saliva necessary for our digestion. In a mouth chewing a food by teeth and lingual. In the mouth cavity begin digestion of carbohydrates by alfa-amilase – ptyalin. To secrete different types of saliva for digestion processes – with a big quantity of water or organic and inorganic substances.

Quantity, composition and properties of saliva Quantity, composition and properties of saliva (In the case of dream produce nearly 0,05 mL/minute, in the normal condition – 0,5 mL/minute, in the case of maximal secretion – near 5 mL/minute. By day produce 0,8-1,5 L of saliva. Composition of saliva: water, organic – alfa-amilase, lipase, phosphatase, RNAase, DNAase, mucin, substances for protective – lisocim, thiocianates, antibodies – and unorganic substances – sodium, potassium, calcium, chlorites, etc. Quantity, composition and properties of saliva (In the case of dream produce nearly 0,05 mL/minute, in the normal condition – 0,5 mL/minute, in the case of maximal secretion – near 5 mL/minute. By day produce 0,8-1,5 L of saliva. Composition of saliva: water, organic – alfa-amilase, lipase, phosphatase, RNAase, DNAase, mucin, substances for protective – lisocim, thiocianates, antibodies – and unorganic substances – sodium, potassium, calcium, chlorites, etc.

Mechanism of saliva forming In acinars' cells produce primary saliva in which synthesis necessary amino acids, glucose, mineral substances (for example, Ca ++ ). In the cells of salivary glands occur passive processes, which provide moving of water and electrolits from blood to the glands’ ductus (strait). In the ductus occur reabsorption of sodium, chlorine, secretion of potassium, HCO 3 –. This is the secondary saliva. Aldosterone increase reabsorption of sodium and secretion of potassium. In acinars' cells produce primary saliva in which synthesis necessary amino acids, glucose, mineral substances (for example, Ca ++ ). In the cells of salivary glands occur passive processes, which provide moving of water and electrolits from blood to the glands’ ductus (strait). In the ductus occur reabsorption of sodium, chlorine, secretion of potassium, HCO 3 –. This is the secondary saliva. Aldosterone increase reabsorption of sodium and secretion of potassium.

Role of saliva in vitality of human 1. Moisten of solid food; 1. Moisten of solid food; 2. Dissolving of substances; 2. Dissolving of substances; 3. Moisten of mouth; 3. Moisten of mouth; 4. Cover food; 4. Cover food; 5. To help of swallowing; 5. To help of swallowing; 6. Primary hydrolyzing of carbohydrates; 6. Primary hydrolyzing of carbohydrates; 7. Antibacterial properties; 7. Antibacterial properties; 8. Neutralized the stomach juice. 8. Neutralized the stomach juice.

Mechanism of saliva formation

Formation of saliva Conditional reactions caused by appearance of food, it smell and other stimulus, which are connect with food. Conditional reactions caused by appearance of food, it smell and other stimulus, which are connect with food.

Unconditional influences have parasympathetic and sympathetic components. Parasympathetic components beginning from receptors of tongue and oral cavity. From its impulses pass through the fibers of n. trigeminus, n. facialis, n. vagus, n. glossopharyngeus, to the center of salivation. Impulses return to saliva glands by n. facialis, n. glossopharyngeus. Sympathetic components of unconditional influences beginning from side cornu of upper thoracic segments of spinal cord – Th 2 -Th - 4. Then impulses go to saliva glands through the upper cervix sympathetic ganglion. The cortex of big hemispheres, hypothalamus, lymbic system regulate the salivation through these nerves. Conditional signals, emotions may inhibit salivation. Unconditional influences have parasympathetic and sympathetic components. Parasympathetic components beginning from receptors of tongue and oral cavity. From its impulses pass through the fibers of n. trigeminus, n. facialis, n. vagus, n. glossopharyngeus, to the center of salivation. Impulses return to saliva glands by n. facialis, n. glossopharyngeus. Sympathetic components of unconditional influences beginning from side cornu of upper thoracic segments of spinal cord – Th 2 -Th - 4. Then impulses go to saliva glands through the upper cervix sympathetic ganglion. The cortex of big hemispheres, hypothalamus, lymbic system regulate the salivation through these nerves. Conditional signals, emotions may inhibit salivation.

Influence of vegetative nerves on secretor activity of salivary glands Stimulation of the parasympathetic nerve supply causes profuse secretion of watery saliva with a relatively low content of organic material. Stimulation of the sympathetic nerve supply causes profuse secretion of saliva with small quantity of water with a relatively big content of organic material. Stimulation of the parasympathetic nerve supply causes profuse secretion of watery saliva with a relatively low content of organic material. Stimulation of the sympathetic nerve supply causes profuse secretion of saliva with small quantity of water with a relatively big content of organic material.

Mediator of parasympathetic nerve system – acetylcholine – stimulate M-cholinoreceptors of baso- lateral membrane and activate entrance of Ca 2+ and activate kalmodulin. These reaction caused production of a big quantity of saliva with low quantity of organic substances. Mediator of sympathetic nerve system – norepinephrine – stimulate adrenoreceptors of basolateral membrane, activated adenilatcyclase that form cAMP. These reaction caused production of a small quantity of saliva which have a big quantity of organic substances. Mediator of parasympathetic nerve system – acetylcholine – stimulate M-cholinoreceptors of baso- lateral membrane and activate entrance of Ca 2+ and activate kalmodulin. These reaction caused production of a big quantity of saliva with low quantity of organic substances. Mediator of sympathetic nerve system – norepinephrine – stimulate adrenoreceptors of basolateral membrane, activated adenilatcyclase that form cAMP. These reaction caused production of a small quantity of saliva which have a big quantity of organic substances.

Swalowing