Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Lymph (Interstitial Fluid) is a colorless fluid that filters out of the blood capillaries into the intercellular spaces of tissues.
The composition of lymph is similar to blood plasma but it lacks (Red Blood Cells), platelets, and large plasma proteins.
Lymph contains specialized (White Blood Cells) called lymphocytes, which are vital for the body's immune response.
Exchange of nutrients, gases (, ), and hormones between the blood and the cells always occurs through this fluid.
An elaborate network of vessels called the lymphatic system collects this fluid and drains it back to the major veins.
Lacteals are specialized lymph capillaries found in the intestinal villi that are responsible for the absorption of fats.
📐Formulae
💡Examples
Problem 1:
A student observes a fluid sample under a microscope and finds a high concentration of lymphocytes but a complete absence of . Is this sample likely to be blood or lymph?
Solution:
The sample is likely to be .
Explanation:
Unlike blood, which contains , , and platelets, lymph contains only (specifically lymphocytes) and lacks and platelets. The presence of lymphocytes and the absence of are diagnostic features of lymph.
Problem 2:
Explain the role of lymph in the digestive system regarding fat absorption.
Solution:
Fats are absorbed into .
Explanation:
Dietary fats (chylomictons) are too large to enter the blood capillaries directly. They are absorbed into the (lymphatic capillaries) in the villi of the small intestine, forming a milky fluid called chyle, which eventually enters the bloodstream.