Dictionary

thrive, failure to See failure to thrive.

thorax The area of the body that is located between the abdomen and the neck. Within the thorax are the lungs, the heart, and the first section of the aorta. Also known as chest.

thoracotomy An operation to open the chest, usually in order to gain access to the lungs or heart.

thoracic vertebrae The 12 vertebrae situated between the cervical (neck) vertebrae and the lumbar vertebrae. The thoracic vertebrae provide attachment for the ribs and make up part of the back of the thorax (chest). The thoracic vertebrae are represented by the symbols T1 through T12. See also vertebra; vertebral column.

thoracic outlet syndrome A condition that is due to compromise of blood vessels or nerve fibers between the armpit (axilla) and the base of the neck, because of compression by adjacent tissues. Symptoms include pain, arm weakness, and numbness in the hands and fingers. Thoracic outlet syndrome can be caused by muscle development from some…

thoracic duct A vascular structure that recirculates lymph from the lymphatic circulation into the bloodstream. The thoracic duct begins in the abdomen, tracks alongside the aorta and esophagus, and eventually joins with the left brachiocephalic vein.

thoracic aorta The part of the aorta that lies within the chest. The thoracic aorta starts after the arch of the aorta and runs down to the diaphragm, the great muscle that separates the chest from the abdomen. The thoracic aorta gives off numerous branches that supply oxygenated blood to the chest cage and the…

thoracic Pertaining to the chest. For example, the thoracic aorta is the part of the aorta that lies within the chest.

thoracentesis Removal of fluid from the space between the lungs and the chest wall (the pleural cavity) for diagnostic or therapeutic purposes using a needle inserted between the ribs.

third ventricle One cavity in a system of four communicating cavities within the brain that are continuous with the central canal that contains the spinal cord. The third ventricle is a median (midline) cavity in the brain and is bounded by the thalamus and hypothalamus on either side. It communicates anteriorly (in front) with the…

third and fourth pharyngeal pouch syndrome See DiGeorge syndrome.

thighbone See femur.