Ileum

Definition

The ileum is the final and longest section of the small intestine, connecting the jejunum to the large intestine. It plays a crucial role in the absorption of nutrients and the normal microbiota of the digestive system.

5 Must Know Facts For Your Next Test

1. The ileum is approximately 3-5 meters long and accounts for the majority of the small intestine's length.
2. It is responsible for the absorption of vitamin B12, bile salts, and the last stages of carbohydrate, protein, and fat digestion.
3. The ileum contains Peyer's patches, which are lymphoid follicles that play a role in the immune function of the digestive system.
4. The ileocecal valve at the junction of the ileum and the large intestine regulates the flow of contents from the small to the large intestine.
5. The normal microbiota of the ileum is dominated by Firmicutes and Bacteroidetes, which aid in nutrient absorption and provide protection against pathogens.

Review Questions

• Describe the anatomical location and function of the ileum within the digestive system.
  • The ileum is the final and longest section of the small intestine, connecting the jejunum to the large intestine. It is responsible for the absorption of a variety of essential nutrients, including vitamin B12, bile salts, and the final stages of carbohydrate, protein, and fat digestion. The ileum also contains Peyer's patches, which play a role in the immune function of the digestive system.
• Explain the role of the ileum in the normal microbiota of the digestive system.
  • The ileum is home to a diverse and complex community of microorganisms, known as the normal microbiota. This microbiota is dominated by the phyla Firmicutes and Bacteroidetes, which aid in nutrient absorption and provide protection against harmful pathogens. The normal microbiota of the ileum is an essential component of the digestive system, contributing to overall gut health and immune function.
• Analyze the importance of the ileocecal valve in the functioning of the ileum and the overall digestive system.
  • The ileocecal valve, located at the junction of the ileum and the large intestine, plays a critical role in regulating the flow of contents from the small to the large intestine. This valve ensures that the contents of the ileum are not prematurely released into the large intestine, allowing for the complete absorption of nutrients and the proper functioning of the digestive system. Dysfunction or impairment of the ileocecal valve can lead to various gastrointestinal issues, underscoring the importance of this anatomical feature in maintaining the overall health and efficiency of the digestive tract.

Related terms

Small Intestine: The small intestine is the longest part of the digestive tract, responsible for the majority of nutrient absorption. It is divided into three sections: the duodenum, jejunum, and ileum.

Villi: Microscopic finger-like projections that line the inner surface of the small intestine, greatly increasing the surface area for nutrient absorption.

Peristalsis: The rhythmic, wave-like muscle contractions that move food through the digestive tract.