Information about Hemolymph
Hemolymph is the scientific name for insect "blood." The circulatory system of insects differs from that of vertebrates and many other invertebrates in being "open". In insects, "blood" is confined to vessels during only a portion of its circuit through the body. The remainder of its journey takes place within the body cavity (called the hemocoel)
The volume of hemolymph needed for such a system is kept to a minimum by a reduction in the size of the body cavity. The hemocoel is divided into chambers called sinuses.
In the grasshopper, the closed portion of the system consists of tubular hearts and an aorta running along the dorsal side of the insect. The hearts pump hemolymph into the sinuses of the hemocoel where exchanges of materials take place.
Coordinated movements of the body muscles gradually bring the hemolymph back to the dorsal sinus surrounding the hearts. Between contractions, tiny valves in the wall of the hearts open and allow hemolymph to enter.
This "open" system might appear to be inefficient compared to closed circulatory systems like ours, but the two have very different demands being placed on them. In vertebrates, the circulatory system is responsible for transporting oxygen to all the tissues and removing carbon dioxide from them. It is this requirement that establishes the level of performance demanded of the system. The efficiency of the vertebrate system is far greater than is needed for transporting nutrients, hormones, etc.. Whereas in insects, exchange of oxygen and carbon dioxide occurs in the tracheal system. Hemolymph plays no part in the process. There is not even an oxygen-carrying pigment in insect hemolymph. Therefore, the demands placed upon the system are much lower.
The volume of hemolymph needed for such a system is kept to a minimum by a reduction in the size of the body cavity. The hemocoel is divided into chambers called sinuses.
In the grasshopper, the closed portion of the system consists of tubular hearts and an aorta running along the dorsal side of the insect. The hearts pump hemolymph into the sinuses of the hemocoel where exchanges of materials take place.
Coordinated movements of the body muscles gradually bring the hemolymph back to the dorsal sinus surrounding the hearts. Between contractions, tiny valves in the wall of the hearts open and allow hemolymph to enter.
This "open" system might appear to be inefficient compared to closed circulatory systems like ours, but the two have very different demands being placed on them. In vertebrates, the circulatory system is responsible for transporting oxygen to all the tissues and removing carbon dioxide from them. It is this requirement that establishes the level of performance demanded of the system. The efficiency of the vertebrate system is far greater than is needed for transporting nutrients, hormones, etc.. Whereas in insects, exchange of oxygen and carbon dioxide occurs in the tracheal system. Hemolymph plays no part in the process. There is not even an oxygen-carrying pigment in insect hemolymph. Therefore, the demands placed upon the system are much lower.
Insecta
Linnaeus, 1758
Orders
Subclass Apterygota
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Linnaeus, 1758
Orders
Subclass Apterygota
- * Archaeognatha (bristletails)
- * Thysanura (silverfish)
- * Infraclass Paleoptera (Probably paraphyletic)
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Blood is a specialized biological fluid consisting of red blood cells (also called RBCs or erythrocytes), white blood cells (also called leukocytes) and platelets (also called thrombocytes) suspended in a complex fluid medium known as blood plasma.
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A Hemocoel is a cavity or series of spaces between the organs of organisms with open circulatory systems like most arthropods and mollusks. A combination of blood, lymph, and interstitial fluid called hemolymph circulates through the hemocoel.
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A Hemocoel is a cavity or series of spaces between the organs of organisms with open circulatory systems like most arthropods and mollusks. A combination of blood, lymph, and interstitial fluid called hemolymph circulates through the hemocoel.
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299: 558-560.
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Herod_Archelaus
