Why portal system exist?

1. To ensure efficient delivery of nutrients to hepatocytes:

The portal system ensures that nutrient-rich blood from the digestive organs (stomach, intestines, pancreas, and spleen) is first directed to the liver before it enters the systemic circulation. This allows the liver to process and store nutrients, as well as remove any toxins or waste products before they reach other organs and tissues.

2. To facilitate detoxification and metabolism of drugs and toxins:

The liver is responsible for detoxifying and metabolizing various substances, including drugs, alcohol, and toxins. The portal system ensures that these substances are delivered directly to the liver, where they can be processed and eliminated efficiently.

3. To regulate nutrient levels in the bloodstream:

The liver plays a crucial role in regulating the levels of nutrients in the bloodstream. It can store excess nutrients, such as glucose, glycogen, and vitamins, and release them when needed to maintain homeostasis. The portal system allows the liver to sense and respond to changes in nutrient levels quickly.

4. To produce bile for fat digestion:

The liver produces bile, which is essential for the digestion and absorption of fats. Bile is stored in the gallbladder and released into the small intestine when needed. The portal system ensures that bile is delivered to the small intestine along with the nutrients from the digestive organs.

5. To protect the body from harmful substances:

The liver acts as a filter, removing bacteria, viruses, and other harmful substances from the bloodstream. The portal system ensures that these harmful substances are intercepted before they can reach the rest of the body.

6. To regulate blood flow to the digestive organs:

The portal system helps regulate blood flow to the digestive organs. When digestion is active, the blood flow to the digestive organs increases to meet the increased demand for nutrients and oxygen. When digestion is not active, the blood flow to the digestive organs decreases, allowing other organs and tissues to receive more blood.