An uncinate process is a term used to refer to an appendage or a feature in vertebrate animals that is hooked in appearance, or is shaped like a hook at one end. The word comes from the Latin unicatus, which means “hooked.” The uncinate process can apply to various parts of the body.
One of the more popular variants is the uncinate process of the pancreas, an organ instrumental in the digestive system and the production of certain hormones such as insulin. The uncinate process of the pancreas is a section of the organ’s head formed by the abdominal aorta, which is the abdominal cavity’s largest artery. It is also formed by the superior mesenteric artery (SMA) that comes out of its anterior surface and is actually where the abdominal aorta comes from.
The hooked part of the pancreas is distinctive from others in that it hooks to the organ’s superior mesenteric vessels from its posterior. These are branches of blood vessels to the pancreas and intestine, of which the SMA is a member. The uncinate process of the pancreas is clinically significant due to its tendency to become a site for cancer that is exceedingly rare and hard to diagnose, and presents a dreadful prognosis.
Another variant is the uncinate process of vertebra. This is a hook-shaped feature that is found on the side edges of some vertebra, which are bones that form the 24-bone structure called the vertebral column, also known as the backbone or spine. The vertebrae that bear the uncinate process are the third to the seventh structures. The first of the 12 thoracic vertebrae that forms the column’s middle section also has it. The uncinate process of vertebra is significant because without this feature, each vertebra would slide backward off the one situated below it.
An uncinate process can be found in the ethmoid bone, which is a skull bone responsible for providing a barrier between the brain and nasal cavity. Its location is at the nose, right between the sockets that contain the eyes. The uncinate process of ethmoid bone comprises a small portion of the maxillary sinus’ middle wall.
The uncinate processes of the ribs are associated not with humans, but with birds. They are bony projections or extensions that provide a sort of bracing for the rib cage due to their overlap with each preceding rib. It also aids in normal or optimal respiration for the bird. The uncinate processes of the ribs vary in size according to the type of bird, with the smaller projections found in walking species and the larger ones found in diving birds.