Difference Between Open and Closed Circulatory System

When multicellular organisms need a circulatory system to transport oxygen and nutrients through the body, that procedure is known as the Circulatory system. There are two types of circulatory systems namely - 

  • Open Circulatory System is the system that is primarily found in invertebrates. Here, the blood flows freely through cavities and there are no vessels to conduct the blood.

  • Closed Circulatory System: is the system that is found in vertebrates and a few invertebrates like earthworms. This system in the presence of vessels conducts blood  throughout the body.

The major difference between the open and closed circulatory system is the way blood flows in an organism. Blood flows inside the body through vessels such as arteries and veins. This type of circulation is called Closed circulation. Open circulation takes place in the absence of vessels to contain the blood and it flows freely through the cavities of the body. 

Vertebrates and few invertebrates follow a closed circulatory system. The open circulatory system, on the other hand, is most commonly seen in invertebrates such as cockroaches and crabs.

The other major difference between Open and Closed Circulatory System are summarized below:

Difference Between Open and Closed Circulatory System

Open Circulatory System

Closed Circulatory System

The hemolymph directly bathes the organs and tissues.

The blood circulates within closed vessels.

The blood and interstitial fluid cannot be distinguished.

Blood and interstitial fluid are distinct.

Present in molluscs and arthropods.

Present in annelids and vertebrates.

Blood is pumped into the body cavity.

Blood is pumped through the vessels by the heart.

Dorsal blood vessel present.

Dorsal and ventral blood vessels present.

Capillary system is absent.

Capillary system found.

Blood is in direct contact with the tissues.

Blood is not in direct contact with the tissues.

Nutrients are exchanged directly between blood and tissues.

The nutrients are exchanged via tissue fluid.

No transport of gases.

Gases are transported.

The fluid flowing in this system is called hemolymph.

Fluid flowing in this system is called blood.

No respiratory pigments are present.

Respiratory pigments are present.

The volume of blood cannot be controlled.

Volume of blood can be controlled by contraction and relaxation of blood vessels.

Blood flow is slow.

Blood flow is rapid.

The open spaces are called sinuses and lacunae.

Closed spaces involve arteries and veins.

Organisms with OCS: Snails, clams, cockroaches and spiders.

Organisms with CCS: Humans, squids, Cats, earthworms.


Human Circulatory System 

Human beings follow a closed circulatory system which means that blood is always enclosed in vessels and the heart while circulating throughout the body. Traveling through arteries and veins, blood carries important molecules throughout the body and is always confined.

Advantage of Closed Circulatory System

Compared to the open circulatory system, the closed circulatory system operates with much higher blood pressure, though it is said to be more efficient considering that it uses much less blood for even faster and higher levels of distribution.

FAQ (Frequently Asked Questions)

Q1. What is a Circulatory System? 

Ans - When multicellular organisms need a circulatory system to transport oxygen and nutrients through the body, that procedure is known as the Circulatory system.

Q2. What are the Types of Circulatory System?

Ans - There are two types of circulatory systems namely - 

  • Open circulatory system is the system that is primarily found in invertebrates. Here, the blood flows freely through cavities and there are no vessels to conduct the blood.

  • Closed circulatory system: is the system that is found in vertebrates and a few invertebrates like earthworms. This system in the presence of vessels conducts blood  throughout the body.

Q3. Define Human Circulatory System? 

Ans - Human beings follow a closed circulatory system which means that blood is always enclosed in vessels and the heart while circulating throughout the body. Traveling through arteries and veins, blood carries important molecules throughout the body and is always confined.

Q4. Where Does Open Circulation Take Place?

Ans - Open circulation takes place in the absence of vessels to contain the blood and it flows freely through the cavities of the body.

Q5. What Type of Circulatory System do Humans have? 

Ans - Humans have a closed circulatory system. The blood is enclosed in the vessels and the heart while circulating. The blood travels through arteries and veins and carries important molecules throughout the body.

Q6. What are the Main Components of the Circulatory System?

Ans - The main components of the circulatory system are - 

  1. Blood 

  2. Blood vessels 

  3. Heart 

Q7. Name the Organisms with Open Circulatory System and Closed Circulatory System Respectively. 

Ans - Organisms with Open Circulatory System are - Snails, clams, cockroaches and spiders. 

Organisms with Closed Circulatory System are - Humans, squids, Cats, earthworms. 

Q8. What is the Advantage of Closed Circulatory System? 

Ans - Compared to the open circulatory system, the closed circulatory system operates with much higher blood pressure, though it is said to be more efficient considering that it uses much less blood for even faster and higher levels of distribution.