Small Intestine
The small intestine is a crucial part of the digestive system. It is a long, narrow tube that is about 20 feet long in adults and is coiled in the abdomen. The small intestine is where the majority of digestion and nutrient absorption takes place.
Anatomy of the Small Intestine:
The small intestine is divided into three main parts: the duodenum, the jejunum, and the ileum. The duodenum is the first and shortest part of the small intestine, followed by the jejunum and then the ileum. The inner lining of the small intestine contains millions of tiny finger-like projections called villi, which increase the surface area for absorption of nutrients.
Functions of the Small Intestine:
1. Digestion: The small intestine plays a key role in breaking down food into its nutrients. Enzymes from the pancreas and bile from the liver help to further break down proteins, carbohydrates, and fats.
2. Absorption: The villi in the small intestine absorb the nutrients from the digested food, including sugars, amino acids, and fatty acids. These nutrients are then passed into the bloodstream to be transported to the cells throughout the body.
Study Guide:
When studying the small intestine, it is important to understand its anatomy, functions, and the processes of digestion and absorption. Here are some key points to focus on:
- Parts of the small intestine: duodenum, jejunum, ileum
- Structure of the small intestine, including the villi
- Role of enzymes and bile in digestion
- Absorption of nutrients in the small intestine
- Comparison of the functions of the small intestine with other parts of the digestive system
It is also helpful to understand common disorders or diseases that can affect the small intestine, such as celiac disease, Crohn's disease, and malabsorption syndromes.
Studying the small intestine in conjunction with the other parts of the digestive system, such as the stomach and large intestine, can provide a comprehensive understanding of how the body processes and absorbs nutrients from food.
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