Functions of the Gastrointestinal Tract

What is the primary function of the gastrointestinal tract?

What is the main role of the pancreas, gallbladder, and salivary glands in relation to the gastrointestinal tract?

What is the purpose of the intestine's motility patterns?

What happens to residues of a meal that cannot be absorbed by the body?

Why does the gastrointestinal system have a large number of regulatory mechanisms?

In addition to its primary functions, what other systems does the gastrointestinal tract harbor?

What is the function of sphincters in the intestinal tract?

What is the role of the lamina propria in the intestine?

Which nerve plexus is located within the submucosa of the intestine?

What is the name of the fingerlike projections that maximize nutrient absorption in the small intestine?

Which organ delivers secretions into the lumen, particularly in the stomach and mouth?

What is the role of the biliary system of the liver in digestion?

Gastrointestinal Tract Function

The primary function of the gastrointestinal tract is to absorb nutrients and water into the body.
The meal is mixed with secretions from the gastrointestinal tract, pancreas, gallbladder, and salivary glands.
The intestine displays various motility patterns to mix the meal with digestive secretions and move it along the length of the gastrointestinal tract.
The gastrointestinal system has evolved regulatory mechanisms to coordinate the function of the gut and organs that drain into it.

Structural Considerations

The gastrointestinal tract consists of the mouth, esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, rectum, and anus.
Glandular structures deliver secretions into the lumen, particularly in the stomach and mouth.
Secretions from the pancreas and the biliary system of the liver are important for digestion.
The intestine has a substantial surface area, which is important for its absorptive function.
Muscle rings known as sphincters restrict the flow of intestinal contents to optimize digestion and absorption.

Intestinal Layers

The intestine is composed of functional layers, including a single layer of columnar epithelial cells, a layer of loose connective tissue known as the lamina propria, and concentric layers of smooth muscle.
The enteric nervous system consists of the myenteric and submucosal nerve plexuses, which innervate the epithelium and muscle layers.
The intestine is also supplied with blood vessels and lymphatics.

Epithelial Specialization

The epithelium of the intestine is further specialized with fingerlike projections called villi, which maximize the surface area available for nutrient absorption.
Between the villi are infoldings known as crypts.

Explore the primary function of the gastrointestinal tract in absorbing nutrients and water, as well as the role of secretions from organs like the pancreas, gallbladder, and salivary glands. Learn about the motility patterns of the intestine that aid in mixing meals with digestive secretions and moving food along its length.