pH Values Throughout the Digestive System
Let's take a fascinating journey through our digestive system and explore how pH levels change dramatically from start to finish! Understanding these pH variations is crucial as they play a vital role in digestion and nutrient absorption.
The pH Scale Quick Reminder
Before we dive in, let's quickly refresh what pH means:
- pH scale ranges from 0 (most acidic) to 14 (most basic/alkaline)
- 7 is neutral
- Below 7 is acidic
- Above 7 is basic/alkaline
pH Values Along the Digestive Tract
Mouth (Oral Cavity)
- pH range: 6.5-7.5
- Slightly acidic to neutral
Saliva contains enzymes that work best at this near-neutral pH, starting the digestion of carbohydrates.
Stomach
- pH range: 1.5-3.5
- Extremely acidic
This highly acidic environment is crucial for:
- Breaking down proteins
- Killing harmful bacteria
- Activating pepsin (protein-digesting enzyme)
Small Intestine
- Duodenum (First part)
- pH range: 6.0-7.0
- Gradually becomes more alkaline
- Jejunum and Ileum
- pH range: 7.0-8.0
- Slightly alkaline
The dramatic pH change from stomach to small intestine is achieved by sodium bicarbonate secreted by the pancreas.