In vertebrate anatomy, ribs are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax. In some animals, especially snakes, ribs may provide support and protection for the entire body.
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The left and right brachiocephalic veins are major veins in the upper chest, formed by the union of each corresponding internal jugular vein and subclavian vein. This is at the level of the sternoclavicular joint. The left brachiocephalic vein is nearly always longer than the right.
The mediastinum is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagus, the trachea, the phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph nodes of the central chest.
In human anatomy, the internal thoracic artery (ITA), previously commonly known as the internal mammary artery, is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one running along each side of the sternum, to continue after its bifurcation as the superior epigastric and musculophrenic arteries.
The sternal angle is the synarthrotic joint formed by the articulation of the manubrium and the body of the sternum.
The sternothyroid muscle, or sternothyroideus, is an infrahyoid muscle in the neck. It acts to depress the hyoid bone. It is below the sternohyoid muscle. It is shorter and wider than the sternohyoid.
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum, and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation.
The anterior superior iliac spine is a bony projection of the iliac bone, and an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis. It provides attachment for the inguinal ligament, and the sartorius muscle. The tensor fasciae latae muscle attaches to the lateral aspect of the superior anterior iliac spine, and also about 5 cm away at the iliac tubercle.
The supraspinous ligament, also known as the supraspinal ligament, is a ligament found along the vertebral column.
The costal cartilages are bars of hyaline cartilage that serve to prolong the ribs forward and contribute to the elasticity of the walls of the thorax. Costal cartilage is only found at the anterior ends of the ribs, providing medial extension.
The intercostal space (ICS) is the anatomic space between two ribs. Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it.
The sternoclavicular joint or sternoclavicular articulation is the joint between the manubrium of the sternum and the clavicle bone. It is structurally classed as a synovial plane joint and functionally classed as a diarthrosis and multiaxial joint. It is composed of two portions separated by an articular disc of fibrocartilage. The bone areas entering into its formation are the sternal end of the clavicle, the upper and lateral part of the sternum,, and the cartilage of the first rib, visible from the outside as the suprasternal notch. The articular surface of the clavicle is much larger than that of the sternum, and is invested with a layer of cartilage, which is considerably thicker than that on the sternum.
The subcostal nerve is larger than the others. It runs along the lower border of the twelfth rib, often gives a communicating branch to the first lumbar nerve, and passes under the lateral lumbocostal arch.
The styloid process of the ulna is a bony prominence found at distal end of the ulna in the forearm.
The costovertebral joints are the joints that connect the ribs to the vertebral column. The articulation of the head of the rib connects the head of the rib to the bodies of the thoracic vertebrae.
In anatomy, the carina is a ridge of cartilage in the trachea that occurs between the division of the two main bronchi.
The costal margin, also known as the costal arch, is the lower edge of the chest (thorax) formed by the bottom edge of the rib cage.
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Shaped roughly like a necktie, it is one of the largest and longest flat bones of the body. Its three regions are the manubrium, the body, and the xiphoid process. The word "sternum" originates from the Ancient Greek στέρνον (stérnon), meaning "chest".
The spinal column, characteristic of each vertebrate species, is a moderately flexible series of vertebrae, each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank, and on the other with phylogenetic differences among the vertebrate taxa.
