Lymphatic vs. Circulatory

The lymphatic system is closely associated with the blood system and represents an accessory route by which lymph fluid can flow from the body’s tissues back into the blood stream. Lymph vessels can be categorized into lymph capillaries, precollectors, lymph collectors and lymphatic trunks. Lymph capillaries represent the beginning of the lymphatic drainage system and originate in close proximity to blood capillaries. Lymph capillaries resemble blood capillaries but have a more irregular cell structure, and their walls are more permeable than those of blood capillaries. Because of their unique structure, lymph capillaries are able to absorb larger particles from the tissues, such as proteins, cells, bacteria and other large substances, which cannot be absorbed by blood capillaries. These particles, together with water then travel through an intricate network of precollectors and larger lymph collectors and trunks back into the blood circulation via the venous angles, which are comprised of the internal jugular and subclavian veins on either side of the neck.

On its way back to the blood, lymphatic fluid travels through a successive number of lymph nodes, which filter out impurities from the lymph.

Main Differences between Blood and Lymph Vessels

The circulatory system represents a closed system with the heart as its central motor, and blood and blood vessels as the other structural elements. The main purpose of the blood vessels is the uninterrupted supply of all body tissues with nutrients and oxygenated blood, and the removal of metabolic waste and carbon dioxide from the tissue cells. The part of the circulatory system that delivers blood to and from the lungs is known as the pulmonary circulation, and the flow of blood throughout the rest of the body is administered by the systemic circulation.

The lymphatic system and its vessels do not form a closed circulatory system. It begins with small lymphatic vessels (lymph capillaries) in the body tissues, and...