What is the major difference between absorption pathways of carbohydrates and proteins versus fats?

What is the major difference between absorption pathways of carbohydrates and proteins versus fats?

• A. Carbohydrates and fats are absorbed into the hepatic portal circulation; proteins go to lymphatics.
• B. Carbohydrates are absorbed into lymphatics and fats into the hepatic portal vein.
• C. Carbohydrates and proteins are absorbed into the hepatic portal circulation; fats are packaged as chylomicrons and enter the lymphatic system first.
• D. All nutrients are absorbed into the hepatic portal vein.

Answer: (C)

The key idea is how nutrients are carried after absorption. Carbohydrates and proteins are water‑soluble and are absorbed into the hepatic portal circulation, meaning they travel via the portal vein directly to the liver for processing. Fats, however, are digested into fatty acids and monoglycerides, reassembled into triglycerides, and packed into chylomicrons. These chylomicrons enter the lymphatic system through the lacteals first, not the portal blood, and only later reach the bloodstream via the thoracic duct. So the major difference is the route: portal circulation for carbohydrates and proteins, versus lymphatic transport for fats.

The key idea is how nutrients are carried after absorption. Carbohydrates and proteins are water‑soluble and are absorbed into the hepatic portal circulation, meaning they travel via the portal vein directly to the liver for processing. Fats, however, are digested into fatty acids and monoglycerides, reassembled into triglycerides, and packed into chylomicrons. These chylomicrons enter the lymphatic system through the lacteals first, not the portal blood, and only later reach the bloodstream via the thoracic duct. So the major difference is the route: portal circulation for carbohydrates and proteins, versus lymphatic transport for fats.