Digestive system

Definition

The digestive system consists of organs and structures responsible for the ingestion, digestion, absorption, and elimination of food. It plays a critical role in maintaining homeostasis by breaking down food into nutrients that can be used by the body.

5 Must Know Facts For Your Next Test

1. The gastrointestinal (GI) tract includes the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.
2. Normal microbiota in the digestive system help with food breakdown and prevent colonization by pathogenic organisms.
3. The stomach's acidic environment acts as a barrier to many pathogens but some bacteria like Helicobacter pylori can survive and cause infections.
4. The small intestine is the primary site for nutrient absorption due to its vast surface area lined with villi and microvilli.
5. Disruptions in normal gut microbiota can lead to conditions such as Clostridium difficile infections.

Review Questions

Related terms

Microbiota:

Communities of microorganisms living symbiotically within a host organism.

Helicobacter pylori:

A type of bacteria that causes stomach ulcers and is linked to stomach cancer.

Clostridium difficile:

A bacterium that causes severe diarrhea and colitis, often after antibiotic use.