01 / Location & anatomical relationships
Coiled within the abdomen, continuing from the stomach toward the rectum.
02 / Structure & organization
The intestinal wall generally includes mucosa, submucosa, muscular layers and an outer covering. Enteric neural circuits coordinate secretion and movement. Small and large intestines differ in diameter, mucosal architecture and predominant roles.
03 / Function
The small intestine absorbs most nutrients, while the large intestine absorbs water and forms stool.
04 / Mechanism
The small intestine finishes much chemical digestion and absorbs nutrients. The large intestine handles much of the remaining material, taking up water and forming stool. Muscular walls keep contents moving along both sections.
Part of a bigger picture
The intestines belongs in our digestion collection. Explore the nearby parts to see how this area of the body fits together.
Explore digestion →FOR DEEPER STUDY
Connect structure with function
Track material through each region while distinguishing digestion from absorption. Movement through the lumen and transport across the intestinal wall are separate processes.
Check your understanding
Locate the intestines in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Further reading: NIDDK: Your Digestive System & How It Works.
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.