What is lymph derived from?

What is lymph derived from?

• A. Secretions of the parotid glands
• B. Excreted fluid from the kidneys
• C. Fluids from the gastrointestinal tract
• D. Extracellular fluid of body tissues

Answer: (D)

Lymph comes from the fluid that bathes all the tissues—the extracellular (interstitial) fluid that leaks out of capillaries. This fluid, rich in nutrients and waste to be cleared, is collected by the blind-ended lymphatic capillaries and becomes lymph as it moves through the lymphatic system. It’s then filtered by lymph nodes and returned to the bloodstream. Secretions from the parotid glands are saliva, urine is excreted by the kidneys, and fluids from the gastrointestinal tract are digestive secretions (and, after fat absorption, lymph carries chyle, which is still derived from extracellular fluid). So the source is the extracellular fluid of body tissues.

Lymph comes from the fluid that bathes all the tissues—the extracellular (interstitial) fluid that leaks out of capillaries. This fluid, rich in nutrients and waste to be cleared, is collected by the blind-ended lymphatic capillaries and becomes lymph as it moves through the lymphatic system. It’s then filtered by lymph nodes and returned to the bloodstream. Secretions from the parotid glands are saliva, urine is excreted by the kidneys, and fluids from the gastrointestinal tract are digestive secretions (and, after fat absorption, lymph carries chyle, which is still derived from extracellular fluid). So the source is the extracellular fluid of body tissues.