What is the Difference Between Open Circulatory System and Closed Circulatory System?

The main difference between open and closed circulatory systems lies in the way blood flows within the body. Here are the key differences between the two types of circulatory systems:

Open Circulatory System:

• Primarily found in invertebrates, such as cockroaches and crabs.
• Blood flows freely through cavities, as there are no vessels to contain it.
• Hemolymph (a mixture of blood and interstitial fluid) directly bathes the organs and tissues.
• Blood is pumped into the body cavity, called a hemocoel.
• Hemolymph circulates around the organs within the body cavity, reentering the heart through openings called ostia.

Closed Circulatory System:

• Found in vertebrates and a few invertebrates, like earthworms.
• Blood circulates within closed vessels, such as arteries and veins.
• Blood and interstitial fluid are distinct.
• Present in annelids and vertebrates.
• Blood is contained inside blood vessels and circulates unidirectionally from the heart, around the body, and back to the heart.

In summary, an open circulatory system is characterized by blood flowing freely through body cavities, directly bathing the organs and tissues, and lacking blood vessels. In contrast, a closed circulatory system has blood contained within blood vessels, circulating in a unidirectional manner, and is distinct from the interstitial fluid.

Comparative Table: Open Circulatory System vs Closed Circulatory System

The main difference between open and closed circulatory systems lies in the way blood flows within an organism. Here is a table summarizing the key differences between the two types of circulatory systems:

Open circulatory systems are found in invertebrates such as cockroaches and crabs, while closed circulatory systems are present in vertebrates and a few invertebrates. Closed circulatory systems are more efficient at circulating blood and nutrients due to the faster blood flow and the ability to create pressure.