人体消化系统

消化系统的结构和功能
Structure and function of digestive system
消化系统的功能是摄取、转运、消化食物和吸收营养、排泄废物，这些生理的完成有利于 整个胃肠道协调的生理活动。食物的消化和吸收，供机体所需的物质和能量。食物在消化管内 被分解成结构简单、可被吸收的小分子物质的过程就称为消化。这种小分子物质透过消化管黏 膜上皮细胞进入血液和淋巴液的过程就是吸收。对于未被吸收的残渣部分，消化道则通过大肠 以粪便形式排出体外。
消化系统
Digestive system
消化系统的结构和功能
Structure and function of digestive system
消化系统由消化道和消化腺两大部分组成。消化道:包括口腔、咽、食道、胃、小肠和大肠 等部。消化腺有小消化腺和大消化腺两种。小消化腺散在于消化管各部的管壁内，大消化腺有 三对唾液腺、肝和胰。消化系统是人体八大系统之一。 The digestive system consists of digestive tract and digestive gland. Digestive tract: including oral cavity, pharynx, esophagus, stomach, small intestine and large intestine. There are two kinds of digestive glands: small digestive gland and large digestive gland. The small digestive glands are scattered in the wall of each part of the digestive canal, and the large digestive glands have three pairs of salivary glands, liver and pancreas. The digestive system is one of the eight systems of the human body.
大肠（ Large intestine ）
大肠的主要作用是吸收水分和无机盐，并将食物残渣形成粪便后由肛门排 出体外。 The main function of the large intestine is to absorb water and inorganic salts and discharge food residues from the anus after they form feces.
胃（ Stomach ）
胃有容存食物和分泌胃液、消化食物 的功能。胃液是一种酸性消化液，含酸和 胃蛋白酶等。
The stomach has the function of storing food, secreting gastric juice and digesting food. Gastric juice is an acidic digestive juice containing acid and pepsin.
食管（ Esophagus ）
食管是消化管道的一部分，上接咽， 下通胃。管壁肌肉收缩时，可将食物推 入胃内。
The esophagus is part of the digestive tract, connecting the upper pharynx and the lower stomach. When the muscles of the tube wall contract, food can be pushed into the stomach.
肠（Bwk.baidu.comwels）
小肠（ Small intestine ）
小肠盘曲在腹腔内，长5-6米，是食物消化和吸收的主要场所。 The small intestine coiled in the abdominal cavity, 5 - 6 meters long, is the main place for food digestion and absorption.
The function of the digestive system is to ingest, transport, digest food, absorb nutrition and excrete waste. These physiological functions are beneficial to the coordinated physiological activities of the entire gastrointestinal tract. The digestion and absorption of food provide the body with the material and energy it needs. The process by which food is decomposed into small molecular substances with simple structure and absorbability in the digestive tract is called digestion. This small molecular substance is absorbed by the process of entering blood and lymph through the epithelial cells of digestive tract mucosa. For the unabsorbed residue, the digestive tract is excreted in the form of feces through the large intestine.