Lymph in the human body carries digested and absorbed fat away from which part of the digestive system?

Introduction / Context:

Lymph is a clear fluid that circulates in lymphatic vessels and plays roles in immunity and transport of certain substances. One important function of lymph is the transport of digested fats from the digestive system to the bloodstream. This process involves specialised structures called lacteals present in the intestinal villi. The question asks from which part of the digestive system lymph carries the absorbed fat, so the learner must connect lymph, lacteals, and the small intestine.

Given Data / Assumptions:

• Lymph is known to transport digested and absorbed fats.
• The question asks for the organ or region from which these fats are carried.
• Options list lungs, intestine, stomach, kidneys, and oesophagus.
• We assume a typical human digestive tract with small intestine as the main site of absorption.

Concept / Approach:

Fats are primarily digested in the small intestine through the action of bile and pancreatic lipase. The resulting fatty acids and monoglycerides are absorbed by the epithelial cells of the intestinal villi and then packaged into structures called chylomicrons. These chylomicrons enter lymphatic capillaries known as lacteals located in the villi. From there, the fat rich lymph eventually drains into larger lymphatic vessels and then into the bloodstream. The lungs, stomach, kidneys, and oesophagus are not the primary sites of fat absorption into lymph. Therefore, the correct answer is the intestine, particularly the small intestine villi.

Step-by-Step Solution:

Step 1: Recall that most digestion and absorption of fats takes place in the small intestine. Step 2: Remember that each villus in the small intestine contains a lymphatic capillary called a lacteal. Step 3: Recognise that digested fats enter these lacteals and are carried away by lymph. Step 4: Consider the listed organs and identify which one contains villi with lacteals. Step 5: Select intestine, especially the small intestine villi, as the source from which lymph carries absorbed fat.

Verification / Alternative check:

Diagrams of the small intestine in biology textbooks show finger like villi with blood capillaries and a central lacteal. Annotations typically state that amino acids and sugars enter blood capillaries, while fatty substances enter lacteals. Descriptions of the lymphatic system mention that intestinal lymph is called chyle because of its milky appearance due to absorbed fats. These details confirm that the small intestine is the part from which lymph carries digested fats.

Why Other Options Are Wrong:

Option A, Lungs, are involved in gas exchange, not digestion or fat absorption. Option C, Stomach, mainly performs mechanical mixing and protein digestion and has very limited absorption, mostly of alcohol and some drugs, not fat into lymph. Option D, Kidneys, filter blood to form urine and do not handle fat absorption. Option E, Oesophagus, only transports food to the stomach and has no specialised structures for nutrient absorption.

Common Pitfalls:

Students sometimes confuse the role of lymph with blood and may think that fats are absorbed directly into blood capillaries everywhere in the digestive tract. Others might forget that the stomach is not the main site of fat digestion and absorption. To avoid these mistakes, learners should remember that villi and lacteals are unique to the small intestine and that lymph from these lacteals is the main carrier of absorbed fats into the circulation.

Final Answer:

Lymph carries digested and absorbed fat from the intestine, especially the small intestine villi.