pH of Human Body Organs
The ideal pH of the human body is somewhere between 7.35 and 7.45. When the body pH falls below 6.9, it can lead to a coma. The body’s fluids help in digestion, lubrication, protection and the movement of nutrients and oxygen. The pH levels must be adjusted to carry out these functions in order to correspond to the various body processes. Each body fluid must have its overall levels of acidity or alkalinity, which are assessed on a pH scale.
The pH of spinal fluid, blood, and saliva is all around 7.4. Since it is close to neutral, this level protects tissue from potential damage brought on by pH values at two extreme ends of the pH scale. The pH of the stomach is maintained between 1.5 and 3.5 by proton pumps that control the hydrogen ion content. This extremely acidic liquid aids in digestion by breaking down the food.
pH Levels
| Human Body Parts/Fluids | pH Level |
|---|---|
| Brain | 7.1 – 7.2 |
| Heart | 7.0 – 7.4 |
| Skeletal Muscle | 6.9 – 7.2 |
| Bone | 7.4 |
| Skin | 4.7 – 5.7 |
| Saliva | 6.5 – 7.5 |
| Stomach (gastric secretion) | 1.5 – 3.5 |
| Liver | 7.0 – 7.2 |
| Bile | 7.8 – 8.2 |
| Small intestine | 7.5 – 8.0 |
| Large intestine | 5.5 – 7.0 |
| Pancreatic secretion | 8.0 – 8.3 |
| Urine | 4.6 – 8.0 |
| Capillary blood | 7.35 – 7.4 |
| Venous blood | 7.3 – 7.35 |
| Arterial blood | 7.4 – 7.45 |
pH of blood in arteries and veins is slightly different. The partial pressure of CO2 in the venous blood is usually higher and thus the pH level decreases. The pH of blood in veins is usually 0.02 to 0.05 units lesser than the arterial blood pH.
Impact of pH Balance
At the appropriate pH, several organs are in optimal operation. For instance, the pepsin (stomach) enzyme needs a low pH to act and break down food, whereas the small intestine’s enzymes need a high pH or alkaline environment to work. Similarly, the pH slightly drops around 5.7 near the caecum region and again slightly increases to 6.7 near the rectum region. All these happen due to the change in hydrogen ion concentration. Any disturbance in these pH levels can lead to illness in humans.