Which nutrient(s) are absorbed into the lymphatic system before entering the bloodstream?

• A. Long-chain fatty acids
• B. Short-chain fatty acids
• C. Glucose
• D. Amino acids

Answer: (A)

Verified step by step guidance

1. Understand the role of the lymphatic system in nutrient absorption: The lymphatic system primarily absorbs substances that are not directly soluble in water, such as certain lipids. This is because these substances require specialized transport mechanisms to enter the bloodstream.
2. Identify the types of nutrients that are absorbed into the lymphatic system: Long-chain fatty acids are absorbed into the lymphatic system because they are hydrophobic and require packaging into chylomicrons for transport.
3. Contrast the absorption of other nutrients: Short-chain fatty acids, glucose, and amino acids are water-soluble and are absorbed directly into the bloodstream through the capillaries in the small intestine, bypassing the lymphatic system.
4. Recognize the role of chylomicrons: Long-chain fatty acids are incorporated into chylomicrons within the intestinal cells (enterocytes). These chylomicrons are then transported via the lymphatic system before entering the bloodstream through the thoracic duct.
5. Summarize the key distinction: Long-chain fatty acids are absorbed into the lymphatic system due to their hydrophobic nature and need for specialized transport, while short-chain fatty acids, glucose, and amino acids are absorbed directly into the bloodstream.