Anatomy of the Small Intestine
The small intestine is a tube measuring about 2.5 cm in diameter. The complete small intestine is approximately 600 cm (20 feet) long and coiled in loops, which fill most of the abdominal cavity. It extends from the pyloric sphincter to the ileocecal valve, where it joins the large intestine and is comprised of three parts:
Approximately 25 cm long; proximal end of small intestine; joined to stomach by the pyloric sphincter.
Approximately 200 cm long.
Approximately 300 cm long; joins the cecum at the ileocecal valve.