Entosterna refers to a collective term used in zoology to describe the internal skeletal structures found in certain invertebrate animals, particularly in arthropods. Derived from Greek, where "entos" means "inside" and "sternon" stands for "sternum," entosterna are typically composed of fused segments or plates that form a rigid, supportive framework within the body.
Entosterna play a crucial role in protecting and supporting vital organs and other soft tissues. They are commonly found in arthropods such as insects, crustaceans, and arachnids, where they provide structural integrity and aid in locomotion. These structures are situated internally, beneath the exoskeleton, within the body cavity or hemocoel.
The composition of entosterna can vary depending on the species, but they are often made of chitin, a tough, elastic substance present in the exoskeleton of these animals. In some instances, entosterna may also contain mineralized elements, such as calcite or calcium carbonate, which further enhance their rigidity and durability.
The entosterna of arthropods are highly diverse and can take on various forms, ranging from simple plates or rods to more complex structures with intricate articulations. They provide attachment points for muscles, contributing to the animal's ability to move and exert force. Additionally, entosterna can aid in respiration by providing support for respiratory structures or facilitating the movement of gases within the body.
Overall, entosterna represent an essential component of the internal anatomy of arthropods, contributing to their successful adaptation, locomotion, protection, and survival.
