Ileum

Definition

The ileum is the final and longest section of the small intestine, responsible for the absorption of nutrients from digested food. It connects the jejunum to the large intestine and plays a crucial role in the overall digestive process.

5 Must Know Facts For Your Next Test

1. The ileum is approximately 12 feet (3.6 meters) long and has a larger diameter than the jejunum, the section of the small intestine that precedes it.
2. The ileum is responsible for the absorption of vitamin B12, bile salts, and the remaining nutrients not absorbed in the jejunum.
3. The ileum contains specialized lymphoid tissue called Peyer's patches, which play a role in the body's immune response.
4. Dysfunction or disease of the ileum, such as Crohn's disease or ileitis, can lead to malabsorption of nutrients and other digestive issues.
5. The ileocecal valve, located at the junction of the ileum and the large intestine, helps prevent the backflow of contents from the large intestine into the small intestine.

Review Questions

• Explain the role of the ileum in the digestive process.
  • The ileum is the final and longest section of the small intestine, responsible for the absorption of the remaining nutrients not absorbed in the jejunum. It is lined with villi, which greatly increase the surface area for nutrient absorption. The ileum also plays a role in the body's immune response through the presence of Peyer's patches, and contains the ileocecal valve, which helps prevent the backflow of contents from the large intestine.
• Describe the anatomical features and location of the ileum within the digestive system.
  • The ileum is approximately 12 feet (3.6 meters) long and has a larger diameter than the jejunum, the section of the small intestine that precedes it. It is the final and longest section of the small intestine, connecting the jejunum to the large intestine. The ileum is located in the lower right quadrant of the abdomen, just before the large intestine, and its position and length allow for the complete absorption of nutrients from the digested food.
• Analyze the potential consequences of dysfunction or disease affecting the ileum.
  • Dysfunction or disease of the ileum, such as Crohn's disease or ileitis, can lead to malabsorption of nutrients and other digestive issues. This can result in deficiencies of essential vitamins and minerals, as well as other health problems associated with malabsorption, such as diarrhea, weight loss, and nutrient-related complications. The ileum's role in immune function through Peyer's patches also means that dysfunction can impact the body's ability to respond to pathogens and maintain a healthy gut microbiome.

Related terms

Small Intestine: The small intestine is a long, coiled tube that extends from the stomach to the large intestine, and is the primary site of nutrient absorption in the digestive system.

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, including the ileum.