The torso, also known as the trunk, represents the central part of the human body. It serves as the core from which the head, neck, and limbs extend. This fundamental anatomical segment is a complex structure that houses many of the body’s vital internal organs and provides essential support and connection for movement.
Key Regions
The torso is broadly divided into three primary anatomical regions: the chest, the abdomen, and the pelvis. The chest, or thoracic cavity, forms the upper portion of the torso, enclosed by the rib cage, sternum, and thoracic vertebrae. This area extends from the neck down to the diaphragm, a dome-shaped muscle that separates it from the abdominal cavity.
Below the diaphragm lies the abdomen, which is the largest hollow space within the torso. It stretches from the diaphragm down to the pelvic brim. The abdominal region is enclosed by abdominal muscles at the front and sides, and by part of the vertebral column at the back. The abdomen can be clinically divided into quadrants or nine regions for more precise anatomical referencing.
The lowest part of the torso is the pelvis, situated between the abdomen and the thighs. This basin-shaped region includes the bony pelvis, the pelvic cavity, and the pelvic floor. The pelvic bones form a ring that connects the spine to the lower limbs, providing both support and a passageway for various structures.
Essential Structures and Roles
The thoracic cavity, for instance, houses the respiratory and circulatory systems. The heart and lungs are located here, with the rib cage offering them protection. The trachea and esophagus also pass through this region, connecting the head and neck to the digestive system below.
The abdominal region contains most of the organs involved in digestion, including the stomach, liver, gallbladder, pancreas, and both the small and large intestines. The kidneys and adrenal glands, part of the urinary and endocrine systems respectively, are also situated within the abdomen. These organs collaborate to process food, absorb nutrients, and filter waste from the blood.
The pelvic region contains organs of the urinary and reproductive systems, such as the bladder, rectum, and internal sex organs. The bony pelvis provides a strong framework, supporting the weight of the upper body and transferring loads to the lower limbs. The spine, running through the back of the torso, offers stability and protection to the spinal cord, while also facilitating a wide range of movements through its muscular attachments.