Epactal bones are a group of bones situated between the cranial vault and the axial skeleton in humans. The word "epactal" is spelled /ɛˈpæktəl/ according to the International Phonetic Alphabet. The initial "e" is pronounced as in "red", followed by a short "a" as in "cat". The letter "c" is pronounced like a "k" sound. The second syllable is stressed, with a long "a" as in "day" and a short "u" as in "cut". The final "l" is silent.
Epactal bones are a type of accessory bones found in some vertebrates, typically in the skeleton of the skull. These bones are small and irregularly shaped, often resembling small bony plates or nodules. The term "epactal" originates from the Latin word "epactalus," which means "added to."
Epactal bones are considered non-essential bones that vary in their location and occurrence. They are generally classified as supernumerary bones since they are not present in the standard textbook anatomy of most individuals. However, they can occasionally be found as isolated or multiple extra structures in certain individuals.
The specific functions of epactal bones are still a topic of debate among anatomists and scientists. Some theories propose that they might serve as developmental remnants or remnants of ancestral skeletal structures. In certain cases, epactal bones can potentially cause discomfort or abnormalities if they impinge nearby nerves or blood vessels, leading to pain or dysfunction.
Epactal bones can be detected through various imaging techniques, such as X-rays, computed tomography (CT), or magnetic resonance imaging (MRI). If an epactal bone is causing any discomfort or interfering with the normal functioning of adjacent structures, surgical intervention may be considered for their removal.
Overall, epactal bones are morphologically variable and relatively rare bones that may occasionally manifest as extra structures in the skull or other anatomical areas.
Sutural or Wormian bones.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "epactal" is derived from the Ancient Greek term "epaktos" (ἔπακτος), meaning "intercalary" or "extra". "Bones" is a general term referring to the rigid organs that form the skeletal structure in vertebrates. When combined, "epactal bones" specifically refers to additional bones that sometimes develop independently within a joint or within the sutures (fibrous joints) of the skull.