Circulatory System vs Lymphatic System
The circulatory system is the most important system of the body as it ensures the exchange of substances between all the tissues of the body and the external environment, and the transport of various substances from one bodily organ to another. William Harvey was the first who discovered the function of heart and the circulation of blood. He stated that the heart was a pumping organ provided with valves, to maintain the flow of blood only in one direction; that blood was distributed to the organs by means of deep laying vessels, which he called arteries, and the blood was returned to the heart by more superficial vessels called veins, which still holds true. This system is now called the cardiovascular system. However, there is another system that works in close co-ordination with the cardiovascular system, which is the lymphatic system. These two together form the Circulatory System.
The lymphatic system is a network of vessels just as the cardiovascular system but lacks a pumping heart, and consist of only type of vessels with valves and nodes at certain places like the armpit, thymus, spleen and neck. The fluid circulating in these is called the lymph, which, actually, is derived from blood plasma forced out of the blood vessels. However, it is devoid of any red blood cells and blood proteins. Lymph accumulates in the interstitial spaces as the interstitial fluid. It is circulated by the contraction of muscles adjoining the ducts. The ducts carry the fluid around the body to drain the lymph back in to the circulatory system. Lymph nodes present at certain intervals help filter foreign bodies out of the lymph. The lymph contains leucocytes to support the immunity and defense against diseases. Lymphatic system transports absorbed fats from the small intestine to the liver, circulates the interstitial fluid and plays a significant role in the defense against foreign agents or microbes.
The circulatory system is the combination of the lymphatic system and the cardiovascular system. It comprises of the heart, blood vessels and blood as well as lymph, lymph nodes, and lymphatic vessels. It controls the whole transportation activity in the body. It is responsible for exchange and transportation of gasses, transportation of absorbed food, transportation of hormones and enzymes, carrying waste products from various tissues, and creating immunity and protection from foreign bodies. There are two main types of circulatory systems called open and closed. The open circulatory system is a system in which the blood is free in the body spaces for the most part of the circulation. But in a closed circulation the blood never leaves the blood vessels like in the mammalian circulatory system.
What is the difference between Circulatory System and Lymphatic System?
• The lymphatic system is essentially a part of the circulatory system. Hence, it shares with the circulatory system the function of carrying fluid and dissolved material from one plays to another.
• However, the lymphatic system lacks blood and the two types of vessels: veins and arteries, through which they are carried.
• The fluids of the circulatory system move through the heart, arteries, capillaries, veins and lungs, but lymph just flows through lymphatic vessels.
• The conductive mediums of the circulatory system consist of plasma erythrocytes, leukocytes and platelets. But lymph only consists of lymphocytes, which help create the immune response.
• The conductive mediums of the circulatory system are responsible for the transport of respiratory gasses throughout the body. Since the respiratory pigments are missing form lymph, it cannot contribute to this.
• The circulatory system carries digested food material and wastes from cells to and from organs, but the lymphatic system only carry digested fats.
• The leukocytes in blood pose a defense against the invading foreign bodies and toxins, but it is the lymphocytes of the lymphatic system, which help, build immunity.
• The lymphatic system, hence, is not only well-connected part of the circulatory system, but also an essential part of it.