The key difference between open and close circulatory system lies in how the circulatory fluid, such as blood or hemolymph, is circulated within the body. In an open circulatory system, the circulatory fluid bathes the organs and tissues directly.There is no distinction between the circulating fluid and the interstitial fluid surrounding the cells. While a closed circulatory system has a more defined network of blood vessels that transport the circulatory fluid throughout the body. The circulatory fluid, usually blood, is contained within a closed system of vessels, including arteries, veins, and capillaries.
What is Open Circulatory System?
An open circulatory system is a type of circulatory system found in certain invertebrates, where the circulating fluid, called hemolymph, directly bathes the organs and tissues without being enclosed in blood vessels. In contrast to closed circulatory systems, which are found in vertebrates, an open circulatory system lacks a continuous network of vessels for transporting the circulating fluid.
In an open circulatory system, the hemolymph is pumped by a heart or a series of contractile vessels into interconnected spaces called sinuses or hemocoels. These sinuses are located between the organs and tissues of the body, allowing the hemolymph to directly come into contact with them. The exchange of nutrients, gases, and waste products occurs directly between the hemolymph and the cells.
What is close circulatory system?
A closed circulatory system, also known as a closed vascular system or a closed circulatory system, is a type of circulatory system found in many complex organisms, including humans. It is characterized by the circulation of blood within a network of vessels that form a closed loop, as opposed to an open circulatory system where blood directly bathes the tissues.
In a closed circulatory system, the blood is contained within blood vessels, which include arteries, veins, and capillaries.The heart pumps the blood, which travels through the arteries to reach the organs and tissues. Within the capillaries, the exchange of nutrients, oxygen, and waste products occurs with the surrounding tissues. The deoxygenated blood is then carried back to the heart through the veins to be reoxygenated. Closed circulatory systems are found in vertebrates, including humans, as well as some invertebrates, such as squids and octopuses.
Arteries carry oxygenated blood away from the heart to various parts of the body, while veins return deoxygenated blood back to the heart. Capillaries are small, thin-walled vessels that connect the arteries and veins, facilitating the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.
Open circulatory system vs Close Circulatory System
The primary difference between the open and close circulatory system is given below
| Open Circulatory System | Closed Circulatory System | |
| Definition | A circulatory system where blood is not always enclosed within vessels. It flows freely through open spaces called sinuses or hemocoels. | A circulatory system where blood is always enclosed within blood vessels and flows through a closed network of arteries, veins, and capillaries. |
| Blood | Blood is pumped by the heart into open spaces called sinuses or hemocoels. | Blood is pumped by the heart into a closed network of blood vessels. |
| Vessels | No distinct blood vessels. Blood directly bathes the organs and tissues. | Blood vessels form a network throughout the body, providing a conduit for blood flow. |
| Efficiency | Less efficient in transporting oxygen and nutrients to tissues. | More efficient in transporting oxygen and nutrients to tissues. |
| Respiratory Gases | Oxygen and carbon dioxide diffuse directly between the blood and surrounding tissues. | Oxygen is transported by red blood cells, and carbon dioxide is carried away from tissues. |
| Examples | Insects, most mollusks, and some crustaceans. | Mammals, birds, reptiles, and some fish. |
| Pressure | Blood pressure is low. | Blood pressure is higher due to the closed system. |