Most multi-cellular organisms require a mechanism for transporting nutrients throughout their bodies and for removal of waste products. The circulatory system has evolved over time from simple diffusion through cells, in the early evolution of animals, to a complex network of blood vessels that reach all parts of the human body. This extensive network supplies the cells, tissues and organs with oxygen and nutrients while removing carbon dioxide and waste, the byproducts of respiration. The circulatory system can either be open or closed, depending on whether the blood flows freely in a cavity or is contained in vessels.
What Is Open Circulatory System?
An open circulatory system is a type of circulatory system whereby blood flows through open cavities referred to as lacunae and sinuses; and thus blood is in direct contact with tissue fluids (interstitial fluid). Open circulatory system is present in lower organisms such as:
- Cockroach
- Oysters
- Grasshopper
- Sea scallops
- Snails
- Clams
- Ants
- Butterflies
Advantages Of Open Circulatory System
- Blood comes in direct contact with tissues
- The system does have a complex system of blood vessels
- Blood is pumped directly into body cavities
What You Need To Know About Open Circulatory System
- An open circulatory system is a type of circulatory system whereby blood flows through open cavities referred to as lacunae and sinuses; and thus blood is in direct contact with tissue fluids (interstitial fluid).
- In this system, blood pressure is low and hence this system is less active when compared to closed circulatory system.
- In this system, blood is pumped into body cavities.
- This system is present in lower organisms such cockroach, Mollusks, Snails, Clams and arthropods.
- The fluid which flows in an open circulatory system is referred to as haemolymph.
- Open circulatory system comprises dorsal blood vessels.
- Supply and elimination of material is very slow.
- A capillary system is absent in an open circulatory system.
- Only nutrients are exchanged directly between blood and sinuses in an open circulatory system.
- In this system, tissues are surrounded by haemolymph.
- Blood takes a long time to complete circulation.
- Respiratory pigment, if present, is dissolved in plasma, no red corpuscles are present.
- The volume of blood/haemolymph cannot be controlled in an open circulatory system.
- Gases are not transported via the open circulatory system.
What Is Closed Circulatory System?
A closed circulatory system is a type of circulatory system whereby blood circulates within closed vessels and is distinct from the interstitial fluid. In a closed circulatory system, blood circulates uni-directionally from the heart, around the body and back to the heart.
Closed circulatory system is present in higher organisms such as:
- Human
- All vertebrates (cats, lions, cows, dogs, sheep, goat).
Advantages Of Closed Circulatory System
- Blood takes a short time to complete circulation.
- Supply and elimination of materials is very rapid.
- Blood pressure is high hence; this system is more active
What You Need To know About Closed Circulatory System
- A closed circulatory system is a type of circulatory system whereby blood circulates within closed vessels and is distinct from the interstitial fluid.
- In this system, blood pressure is high hence; this system is more active than open circulatory system.
- This system is present in higher organisms such as human and all vertebrates.
- The fluid which flows in a closed circulatory system is referred to as blood.
- Closed circulatory system comprises both dorsal and ventral blood vessels.
- In this system, blood is pumped by the heart through vessels.
- Supply and elimination of materials is very rapid.
- A capillary system is present in a closed circulatory system.
- Gases and nutrients are exchanged between blood and tissue fluid through the capillaries in a closed circulatory system.
- Blood takes a short time to complete circulation.
- In a closed circulatory system, blood does not directly come in contact with tissues.
- Respiratory pigment is present and may be dissolved in the plasma but is usually held in red blood corpuscles.
- The volume of blood flow is controlled by the contraction and relaxation of blood vessels.
- Gases are transported through the closed circulatory system.
Also Read: Difference Between Arteries And Veins
Difference Between Open And Closed Circulatory System In Tabular Form
| BASIS OF COMPARISON | OPEN CIRCULATORY SYSTEM | CLOSED CIRCULATORY SYSTEM |
| Description | An open circulatory system is a type of circulatory system whereby blood flows through open cavities referred to as lacunae and sinuses; and thus blood is in direct contact with tissue fluids (interstitial fluid). | A closed circulatory system is a type of circulatory system whereby blood circulates within closed vessels and is distinct from the interstitial fluid. |
| Blood Pressure | In this system, blood pressure is low and hence this system is less active when compared to closed circulatory system. | In this system, blood pressure is high hence; this system is more active than open circulatory system. |
| Presence | This system is present in lower organisms such cockroach, Mollusks, Snails, Clams and arthropods. | This system is present in higher organisms such as human and all vertebrates. |
| Blood Flow | In this system, blood is pumped into body cavities. | In this system, blood is pumped by the heart through vessels. |
| Blood/Haemolymph | The fluid which flows in an open circulatory system is referred to as haemolymph. | The fluid which flows in a closed circulatory system is referred to as blood. |
| Makeup | Open circulatory system comprises dorsal blood vessels. | Closed circulatory system comprises both dorsal and ventral blood vessels. |
| Supply And Elimination Of Material | Supply and elimination of material is very slow. | Supply and elimination of materials is very rapid. |
| Capillary System | A capillary system is absent in an open circulatory system. | A capillary system is present in a closed circulatory system. |
| Exchange Of Gases And Nutrients | Only nutrients are exchanged directly between blood and sinuses in an open circulatory system. | Gases and nutrients are exchanged between blood and tissue fluid through the capillaries in a closed circulatory system. |
| Completion Of Circulation | Blood takes a long time to complete circulation. | Blood takes a short time to complete circulation. |
| Tissues | In this system, tissues are surrounded by haemolymph. | In a closed circulatory system, blood does not directly come in contact with tissues. |
| Respiratory Pigment | Respiratory pigment, if present, is dissolved in plasma, no red corpuscles are present. | Respiratory pigment is present and may be dissolved in the plasma but is usually held in red blood corpuscles. |
| Volume of Blood Flow | The volume of blood/haemolymph cannot be controlled in an open circulatory system. | The volume of blood flow is controlled by the contraction and relaxation of blood vessels. |
| Gses | Gases are not transported via the open circulatory system. | Gases are transported through the closed circulatory system. |
Comments are closed.