Composition of digestive system model

The digestive system model consists of two parts: the digestive tract and the digestive gland.

Digestive tract: including oral cavity, pharynx, esophagus, stomach, small intestine (duodenum, jejunum, ileum) and large intestine (cecum, appendix, colon, rectum, anus) and other parts. Clinically, the section from the oral cavity to the duodenum is often called the upper gastrointestinal tract, and the part below the jejunum is called the lower gastrointestinal tract.

There are two types of digestive glands: small digestive glands and large digestive glands. The small digestive glands are scattered in the walls of each part of the digestive tract. The large digestive glands have three pairs of salivary glands (parotid, submandibular, and sublingual), liver and pancreas.

Pharyngeal isthmus: palatine drop, free margin of palatal sail, palatine arch and tongue base on both sides.

Pharyngeal: Divided into nasopharynx, oropharynx, laryngopharyngeal. The pharyngeal opening of the eustachian tube communicates with the tympanum of the middle ear, and infection can cause otitis media.

Eustachian tube round pillow look for signs of the eustachian tube throat.

Pharyngeal recesses are the most common sites for nasopharyngeal carcinoma.

Pharyngeal lymphatic ring: Eustachian tube tonsils, pharyngeal tonsils (adenoids), palatine tonsils, and tongue tonsils.

Esophagus: about 25cm in length, the upper end starts from the lower edge of the sixth cervical vertebral body, and the lower end is flat at the height of the thoracic vertebra and connects with the cardia.

Three physiological stenosis:

①The 6th cervical vertebra at the beginning is at the level of the lower edge, 15cm away from the central incisor.

②At the rear intersection of the left main bronchus, about the level of the 4th and 5th thoracic vertebrae, 25cm away from the central incisor.

③The esophageal hiatus passing through the diaphragm is equivalent to the level of the 10th thoracic vertebra, 40cm away from the central incisor.