Small Intestine

Describe the duodenum

C sahped structure, shortest part. Retroperitoneal with 4 parts: D1-4

What is a feature of D2

Connects with hepatopancreatic ampulla. This empties into D2 to assist digestion. The sphincter of Oddi closes the ampulla.

What is a feature of D4

Projects anterior to connect with jejenum at the DJ junction.

Describe the jejunum

Intraperitoneal, LUQ, 2/5ths of small intestine. The primary site of nutrient absorption.

What are some adaptations of the jejunum to increase its ability to absorb nutrients

Villi & Microvilli, plicae circulares. These increase the surface area.

Describe the Ileum

In the RLQ, 3/5ths of small intestine. The teminal ileum absorbs nutrients such as, B12, minerals, water.

What is the immune function of the ileum

Has a large amount of peyers patchs - cluster of lymphoid tissue that moniter intestinal bacteria and help mount immune responses.