The thorax in a human and an ant.

Diagram of a tsetse fly, showing the head, thorax and abdomen

The thorax is a division of an animal's body that lies between the head and the abdomen. This page is about the insect For other meanings see Tsetse (disambiguation. In Anatomy, the head of an Animal is the Rostral part (from Anatomical position that usually comprises the Brain, Eyes In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis.

In mammals, the thorax is the region of the body formed by the sternum, the thoracic vertebrae and the ribs. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands With regard to living things, a body is the integral physical material of an individual The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column In Vertebrate Anatomy, ribs ( Latin costae) are the long curved Bones which form the ribcage. It extends from the neck to the diaphragm, and does not include the upper limbs. The neck is the part of the Body on many limbed Vertebrates that distinguishes the head from the Torso or trunk For other types of diaphragm see Diaphragm. In the Anatomy of Mammals the thoracic diaphragm is a sheet of Muscle In Human anatomy, the upper limb (also upper extremity) refers to what in common English is known as the arm, that is the region of the shoulder The heart and the lungs reside in the thoracic cavity, as well as many blood vessels. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive The thoracic cavity (or chest cavity) is the chamber of the human body (and other animal bodies that is protected by the Thoracic wall ( Thoracic cage The blood vessels are part of the Circulatory system and function to transport Blood throughout the body The inner organs are protected by the rib cage and the sternum. The human rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic (chest cavity and supports the pectoral

In insects and the extinct trilobites, the thorax is one of the three main divisions (or tagmata) of the creature's body, each of which is in turn composed of multiple segments. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Trilobites ("three-lobes" are extinct Arthropods that form the class Trilobita. In Invertebrate Biology, a tagma (plural tagmata) is a specialized grouping of Arthropodan segments such as the It is the area where the wings and legs attach in insects, or an area of multiple articulating plates in trilobites. Insect wings are outgrowths of the Insect Exoskeleton that enable insects to fly. In most insects, the thorax itself is composed of three segments; the prothorax, the mesothorax, and the metathorax. The prothorax is the foremost of the three segments in the Thorax of an Insect, and bears the first pair of legs The mesothorax is the middle of the three segments in the Thorax of an Insect, and bears the second pair of legs The metathorax is the posterior of the three segments in the Thorax of an Insect, and bears the third pair of legs. In extant insects, the prothorax never has wings, though legs are always present in adults; wings (when present) are restricted to at least the mesothorax, and typically also the metathorax, though the wings may be reduced or modified on either or both segments (as in the fly shown, where the metathoracic wings have been reduced to tiny balancing organs called halteres). This article concerns insect anatomy For halteres as used in ancient sports see Halteres (ancient Greece Halteres (hælˈtɪəriːz singular In the Apocritan Hymenoptera, the first abdominal segment is fused to the metathorax, where it forms a structure known as the propodeum. Hymenoptera is one of the larger orders of Insects comprising the sawflies, Wasps Bees and Ants The name refers to The propodeum is the first abdominal segment in Apocrita Hymenoptera ( Wasps Bees and Ants. Accordingly, in these insects, the functional thorax is composed of four segments, and is therefore typically called the mesosoma to distinguish it from the "thorax" of other insects. The mesosoma is the middle part of the body or tagma, of Arthropods whose body is composed of three parts the other two being the Prosoma and the

Each thoracic segment in an insect is further subdivided into various parts, the most significant of which are the dorsal portion (the notum), the lateral portion (the pleuron; one on each side), and the ventral portion (the sternum). The notum is the Dorsal portion of an Insect 's thoracic segment The pleuron (pl pleura, from Greek side rib is a lateral Sclerite of thoracic segment of an Insect. The sternum (pl "sterna" is the Ventral portion of a segment of an Arthropod Thorax or Abdomen. In some insects, each of these parts is composed of one to several independent exoskeletal plates with membrane between them (called sclerites), though in many cases the sclerites are fused to various degrees. A sclerite ( Greek skleros meaning " hard " is a hardened body part

The trilobite body is divided into three major sections, a cephalon with eyes, mouthparts and sensory organs such as antennae, a thorax of multiple similar segments (that in some species allowed them to roll up into a ball), and a pygidium, or tail section.

References

• Sam Gon III. A guide to the Orders of Trilobites.  . Retrieved on August 23, 2005.