Duodenum

The duodenum is the first part of the small intestine, connecting the stomach to the jejunum. It plays a crucial role in the digestion and absorption of nutrients from the food we eat.

Structure of the Duodenum

The duodenum is divided into four parts: the superior part, descending part, horizontal part, and ascending part. It is approximately 25-30 cm long and is C-shaped, surrounding the head of the pancreas.

Functions of the Duodenum

1. Receives Chyme: The duodenum receives partially digested food, known as chyme, from the stomach.
2. Neutralizes Gastric Acid: The acidic chyme entering the duodenum is neutralized by bicarbonate secreted by the pancreas, creating a more favorable environment for the action of digestive enzymes.
3. Secretion of Digestive Enzymes: The duodenum receives digestive enzymes from the pancreas and bile from the liver and gallbladder, which aid in the breakdown of carbohydrates, proteins, and fats.
4. Absorption of Nutrients: The duodenum absorbs nutrients such as iron, calcium, and magnesium, as well as the products of carbohydrate and protein digestion.

Study Guide

When studying the duodenum, it's important to focus on the following key points:

1. Structure of the duodenum and its parts
2. Functions of the duodenum in digestion and absorption
3. The role of bile and pancreatic enzymes in the duodenum
4. How the duodenum contributes to nutrient absorption

Understanding the anatomy and physiology of the duodenum is essential for comprehending the processes involved in the digestion and absorption of nutrients in the small intestine.

Feel free to use this study guide as a reference while preparing for your biology studies!