Anatomy of the Gastrointestinal Tract

Esophagus:  commonly known as the “food pipe”.  Food passes by peristaltic contractions.

Stomach:  a muscular organ that functions as an important organ in digestion. It secretes digestive enzymes and gastric acid to aid in digestion.

Gall bladder:  a small organ where bile is stored before it is released into the small intestine.

Pancreas:  a digestive organ, secreting pancreatic juice containing digestive enzymes to aid in digestion and absorption of nutrients in the small intestine.

Duodenum:  the first part of the small intestine.  Responsible for breakdown of food using enzymes and is about 25 – 38 cm long.

Jejunum:  the second part of the small intestine, which is about 2.5 cm long.

Ileum:  the third part of the small intestine. And is about 2 – 4 m long.  Its main function is to absorb vitamin B₁₂ and bile salts and whatever products of digestion were not absorbed by the jejunum.

Cecum:  an intraperitoneal pouch that is considered to be the beginning of the large intestine.

Ascending colon:  the part of the colon located between the cecum and the transverse colon.

Transverse colon:  the longest and most movable part of the colon, and crosses the abdomen.

Descending colon:  the function in the digestive system is to store the remains of digested food that will be emptied into the rectum.

Sigmoid colon the part of the large intestine that is closest to the rectum and anus.  It averages about 35 – 40 cm in length.

Rectum the final straight portion of the large intestine.  It acts as a temporary storage site for feces.

Anal canal:  is the terminal part of the large intestine.  It is situated between the rectum and anus.  It is approximately 2.5 – 4 cm long.