Fifth metacarpal bone Fifth metacarpal bone The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most medial and second-shortest of the metacarpal bones. It presents on its base one facet on its superior surface, which is concavo-convex and articulates with the hamate, and one on its radial side, which articulates with the fourth metacarpal. On its ulnar side is a prominent tubercle for the insertion of the tendon of the extensor carpi ulnaris muscle. The dorsal surface of the body is divided by an oblique ridge, which extends from near the ulnar side of the base to
Mylohyoid muscle Mylohyoid muscle The mylohyoid muscle is a paired muscle running from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. It is named after its two attachments near the molar teeth (""mylo"" comes from the Greek word for "molar"). These muscles are mesodermal in embryologic origin. The mylohyoid muscle is derived from the first pharyngeal arch. The mylohyoid muscle is flat and triangular, and is situated immediately superior to the anterior belly of the digastric muscle. It is a pharyngeal muscle (derived from the first pharyngeal arch) and classified as one of the