Mastication of chewing is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow more efficient beak down by enzymes. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occluding and opening. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digesting occurs.



咀嚼(噛むこと)とは歯によって、食べ物が砕かれ、すりつぶされる過程である。それは消化の初期段階である。それによって、食べ物はその表面積が増え、食べ物は酵素によってより小さく分解される。咀嚼の過程で食べ物h胸筋と舌によって、すり潰しやすいように上下の歯の間に運ばれる。咀嚼筋は上下顎を動かして、intermittent contact, 間欠性接触(上下の歯が接触したり離れたり)して咀嚼が継続している間に食べ物は柔らかくなり温度が上がる。そして唾液中の酵素が炭水化物を分解(break down)し、bolusとなって飲み込まれる。Bolusは食道に入り蠕動運動によって胃に運ばれ、そこで次の段階の消化作用がおきる。



Saliva is secreted by salivary glands, 99.5% water, plus electrolyte, mucus, white blood cells, epithelial cells, glycoproteins, enzymes, antimicrobial agents such as IgA and lysozyme.



唾液は唾液腺から分泌される。99.5% が水分で、それに電解質、粘液、白血球、上皮細胞、糖タンパク質、酵素、例えばイミュノグロブリンのような抗微生物物質及びリゾチームが含まれている。



Saliva contributes to the digestion of food and to the maintenance of oral hygiene. Without normal salivary function the frequency of dental caries, gum disease, and other oral problems increase significantly.





Role in taste

Saliva is very important in the sense of taste. It is the liquid medium in which chemicals are carried to taste receptor cells (mostly associated with lingual papillae).

Persons with little saliva often complain of dysgeusia (味覚異常)(i.e. disordered taste, e.g. reduced ability to taste, or having a bad, metallic taste at all times).






Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under “symptom and signs” in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia.

It is usually caused by nerve or muscle problems. Dysphagia may occur after a stroke, throat and mouth cancer, gastroesophageal reflux disease, or as symptom of several different neurological disorders. It may be a sensation that suggests difficulty in the passage of solids or liquids from the mouth to the stomach, a lack of pharyngeal sensation, or various other inadequacies of the swallowing mechanism. Dysphagia is distinguished from other symptoms including odynophagia, which is defined as painful swallowing, and globus, which is the sensation of a lump in the throat. A psychogenic dysphagia is known as phagophobia.



嚥下障害は飲み込むのが困難な症状を意味する医学用語である。症状と客観的所見に分類されているが、その用語は本来の意味で使われる。患者は自分が嚥下障害にかかっていることを自覚していな愛場合もある。一般に神経や筋肉が原因で起きる。嚥下障害は脳溢血の後に、咽頭や口腔のガンで起きることもある。胃食道逆流病gastroesophageal reflux 或いは種々の神経傷害で起きる。それは多分


PEG Percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is an endoscopic medical procedure in which a tube (PEG tube) is passed into a patient‘s stomach through the abdominal wall, most commonly to provide a means of feeding when oral intake is not adequate (for example, because of dysphagia or sedation). This provides enteral nutrition (making use of the natural digestion process of the gastrointestinal tract) despite bypassing the mouth; enteral nutrition is generally preferable to parenteral (消化管以外を通しての投薬等)nutrition (which is only used when the GI tract must be avoided). The PEG procedure is an alternative to open surgical gastrostomy insertion, and does not require a general anesthetic; mild sedation is typically used. PEG tubes may also be extended into the small intestine by passing jejunal extension tube (PEG-J tube) through the PEG tube and into the jejunum via the pylorus.


PEG 経皮的内視鏡胃瘻増設術

内視鏡による腹壁外と胃壁との間に瘻孔を形成する)でチューブ(PEGチューブ)を、腹壁を通して、患者の胃に通す方法で最も一般的には、経口的摂食が十分でない場合の方法である。(例えば嚥下障害、sedation(終末期の患者に疼痛緩和の目的として鎮痛薬で意識レベルが低下した状態)この方法で十分な栄養補給を図る。(この場合自然の消化過程を利用する)口腔を迂回する(口腔をバイパスに)にもかかわらず、消化管以外の方法の場合径腸栄養法は好ましい方法である。PEG法は外科的胃瘻設置術でも、全身麻酔は不要で、一般的に経度の麻酔で行われる。PEG チューブは幽門を通って空腸 を通る場合もある。