What is the difference between open and closed circulatory system?
Multicellular organisms need oxygen and nutrients in their bodies. The blood circulation in their bodies helps to achieve it.
The main difference between open and closed circulatory systems is that an open circulatory system is where blood flow through open cavities whereas the closed circulatory system is where blood flow through closed vessels.
Comparison Table between Open and Closed Circulatory System
| Basic Terms | Open Circulatory System | Closed Circulatory System |
| Definition | It is where blood flows through open cavities. | It is where blood flow through closed vessels |
| Blood Flow Pressure | Very slow speed | Very high speed |
| Duration | Blood circulation take longer time to complete | Blood circulation take a shorter time to complete |
| Blood Volume | Blood volume cannot be controlled | Contraction and relaxation of blood vessels control the volume of blood |
| Respiratory Pigments | Does not occur in the blood | Occur in the blood during transport of gases |
| Circulatory Fluid | Haemolymph flow in the open space | Blood flow closed system |
| Transport of Gases | Do not transport gases | Transport both oxygen and carbon dioxide |
| Exchange of Materials | Only nutrients are exchanged between blood and tissues | Tissue fluid is where gases and nutrients are exchanged |
| Tissues | All tissues are surrounded by blood | Tissues do not come into contact with blood |
| Capillary System | Tend to be absent | Tend to be present |
| Vessels | Comprise of dorsal blood vessel | Comprise of both dorsal and ventral blood vessels. |
| Mechanism | Blood is pumped through the body cavity | Blood is pumped by the heart through the vessels |
| Elimination of Materials | Quite slow | Very fast |
| Examples of Organisms | Mollusks and arthropods | Vertebrates and annelids |
| Blood Flow Vessels | Sinuses and lacunae | Arteries and veins |
What Is Open Circulatory System?
An open circulatory system is a type of circulatory system where blood flows through open cavities known as sinuses and lacunae.
The fluid flowing through the open spaces is known as hemolymph and it tends to flow under very low pressure.
The body tissues normally come into close contact with blood for the exchange of nutrients. The haemolymph comprises organic compounds, salts, and water.
The circulatory cells responsible for boosting the immune system of the animals is Hemocytes. An open circulatory system occurs in mollusks, crustaceans, spiders, and insects.
Advantages of Open Circulatory System
- Require minimal energy for blood distribution
- Suitable for animals with smaller bodies and slower metabolism
- Blood nourishes the body tissues of the organisms due to close contact
Disadvantages of Open Circulatory System
- Oxygen takes longer to reach body parts
- Organisms are less active
- Limited to the small organism
What Is Closed Circulatory System?
The closed circulatory system is where blood flows through close vessels such as arteries and veins. The heart is responsible for pumping blood into the dorsal blood vessel.
The dorsal vessels carry the blood to the organs and tissues in the body. The blood does not get mixed with tissue fluids.
The exchange of materials in the body occurs in the capillaries. Oxygenated blood is transported to various body parts and deoxygenated blood is pumped back into the heart.
Blood flow at high pressure in a closed circulatory system for faster distribution of nutrients into the body. It also comprises of the lymphatic system.
Advantages of Closed Circulatory System
- Enhance faster distribution of nutrients
- Suitable for organisms with a higher metabolism
- Easy elimination of wastes in the body
- Boost the immune system of the organisms
- Prevent contamination of oxygenated blood with deoxygenated blood
Disadvantages of Closed Circulatory System
- Require a lot of energy
- Limited to higher organisms
Main Difference between Open and Closed Circulatory System
- An open circulatory system is where blood flow in open space whereas the closed circulatory system occurs in closed vessels.
- The open circulatory system has slow blood flow whereas the closed circulatory system has very high blood flow speed
- Examples of open circulatory system spaces are sinuses and lacunae while those of closed circulatory systems are arteries and veins.
- Organisms with the open circulatory systems are snails, clams, cockroaches, and spiders while those of closed circulatory systems are humans, squids, Cats, and earthworms.
- Closed circulatory system tend to control blood flow whereas open circulatory system blood flow is not controlled
- The closed circulatory system has respiratory pigment while the open circulatory system has no respiratory pigments
- The fluid flowing in the open circulatory system is known as hemolymph while a closed circulatory system is a blood.
- The closed circulatory system enhances the transport of gases whereas no transport of gases occurs in open circulatory system
- Nutrients are exchanges directly between tissues and blood in an open circulatory system while in closed circulatory system exchange occur via tissue fluid
- The open circulatory system has dorsal blood vessels while the closed circulatory system has both dorsal and ventral blood vessels
Similarities between Open and Closed Circulatory System
- Both occur in higher invertebrates and vertebrates
- Both involve the circulation of fluid in the body
- Both blood flow is governed by the heart
- Both are types of the circulatory system
- Both consists of dorsal blood vessels
Frequently Asked Questions (Open Circulatory System Vs Closed Circulatory System)
- Is Open Or Closed Circulatory System More Efficient?
The closed circulatory system is more efficient since blood flows faster in the body. It also enhances the exchange of nutrients and gases with ease.
- Do Mollusks Have A Closed Circulatory System?
Not really. They have a closed circulatory system that is not dependent on diffusion of blood to reach body tissues. Those mollusks that belong to the class Cephalopoda have an open circulatory system,
- Which Group Has An Open Circulatory System?
The two main groups are arthropods, such as insects, lobsters and crabs, and mollusks, such as oysters and clams.
- Do Bivalves Have An Open Or Closed Circulatory System?
Bivalves have an open circulatory system. They have a heart that has three chambers such as two auricles receiving blood from the gills and a single ventricle.
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Summary
The core difference between closed and open circulatory systems is that closed circulatory systems experience blood flow in the closed vessels whereas open circulatory system blood flow in open cavities.
Open circulatory system blood has direct contact with the tissues and organs whereas closed circulatory system blood has indirect contact with body tissues.
More Sources and References
- Circulatory System. Wikipedia
- Open System. Wikipedia