Small and Large Intestine Anatomy

A set of flashcards covering key terms and definitions related to the anatomy and function of the small and large intestines.

Small Intestine

The longest part of the gastrointestinal tract, about 6 m (20 ft) in cadavers, responsible for digestion and nutrient absorption.

Plicae Circulares

Transverse folds in the intestinal lining that increase surface area for absorption.

Duodenum

The first part of the small intestine, approximately 10 inches long, responsible primarily for digestion.

Jejunum

The middle section of the small intestine, about 2.5 m long, where most chemical digestion and nutrient absorption occurs.

Ileum

The last part of the small intestine, averaging 3.5 m in length, ending at the ileocecal valve.

Mesentery

A broad fan-shaped fold of peritoneum that suspends the small intestine from the posterior abdominal wall.

Large Intestine

The horseshoe-shaped intestine that frames the small intestine, averaging 1.5 m in length, responsible for reabsorption of water and storage of fecal material.

Teniae Coli

Three ribbon-like bands of longitudinal muscle along the large intestine that contribute to its motility.

Appendices Epiploicae

Small bags of visceral peritoneum filled with fat attached to the teniae coli.

Rectum

The final section of the large intestine, approximately 15 cm long, that stores and prepares fecal material for excretion.

Anal Canal

A canal approximately 4 cm long that connects the rectum to the anus, containing internal and external sphincters.

Ileocecal Valve

A sphincter that controls the flow of materials from the ileum into the cecum of the large intestine.

Haustrations

Pouches in the wall of the colon created by the shorter length of teniae coli compared to the circular muscle.

Vermiform Appendix

A small tube-like structure attached to the cecum, containing a large amount of lymphoid tissue.

Cecum

The blind sac that lies below the junction of the ileum and the large intestine, primarily involved in the absorption of fluids and salts.