Digestive system:

 The digestive system in human beings is a form of a long muscular tube called the gastrointestinal tract (GIT) or alimentary canal and accessory organs. 

The GIT pass through the ventral body cavity it extends from the mouth to the anus and consists of the oral cavity, pharynx, esophagus, stomach small/large intestine, rectum, and anal canal

Oral cavity:

 The oral cavity is an irregular space that is bounded by muscles and bones. The oral cavity contains the lips, cheeks, gums, tongue, and plate. The mouth contains the following glands

 1 parotid                                   

 2 sublingual                                                     

 3 submandibular

          

                                                                              pharynges:

 it is 5-6 inches in length its cavity is continuous with the cavities of the nose, mouth, and larynx. The pharynx is separated into three parts i.e.

 1 nasopharynx
 2 oropharynges
 3 laryngeal pharynx 

Esophagus:

 The length of the esophagus is 25cm long and 2cm in diameter. It lies in the central plane in the thorax. In front of the vertebral column. Behind the trachea and heart, it starts from the pharynx and ends in the stomach.

 Stomach: 

This is like a muscular bag that connects above to the lower end of the esophagus and below the duodenum. 1 It is j shaped organ.2 It is 10 inches in length. 

 Small intestine: 

the small intestine encompasses the stomach to the ileocecal junction. The length of the small intestine is about 6.9 m in males and 7.1 m in females (avg=4.6-9.8m).small intestine lies in the abdominal cavity surroundings by the large intestine. The small intestine has three parts.

 1 duodenum (size 2.5-3.8m)
 2 jejuna (size 2.5m) 
 3 ileum (size2-4m)

 Villi: 

The mucous membrane of the small intestine has a microscopic finger-like projection called intestinal villi through which absorption takes place. 

Large intestine: 

The large intestine spreads from the end of the ileum to the anus. It is about 1.5m long.

The large intestine has the following parts:

 1 cecum
 2 colons
 " Ascending colon 
" Transverse colon
 " Descending colon
 " Sigmoid colon 
 3 rectum
 4 anal canal