The bones forming the fingers and toes are known as phalanges. These specialized bones are fundamental to the structure and function of human digits. They enable precise movements in the hands and provide support in the feet.
Location in the Human Body
Phalanges are found in the digits of both the hands and feet. Each hand contains 14 phalanges, forming the skeletal framework of the fingers and thumb. Each foot also has 14 phalanges that make up the toes, totaling 56 phalanges in the human body.
Most fingers and toes have three phalanx bones. The thumb and big toe are exceptions, possessing only two phalanges each.
Anatomy and Classification
Phalanges are classified as long bones. Each phalanx consists of three main parts: a proximal base, a central body or shaft, and a distal head. The base is the end closest to the body, connecting to other bones, while the head articulates with the next bone in the digit.
These bones are categorized into three types based on their position within a digit. The proximal phalanges are the largest and closest to the palm or sole, articulating with the metacarpal bones of the hand or metatarsal bones of the foot. The middle, or intermediate, phalanges are situated between the proximal and distal phalanges; these are absent in the thumb and big toe. The distal phalanges are the outermost bones, forming the tips of the fingers and toes. Each distal phalanx features an expanded, roughened area known as an apical tuft, which supports fingertip pads and nails.
Role in Movement and Dexterity
Phalanges facilitate movement and articulation, enabling diverse actions of the digits. In the hands, they form the structural basis for gripping, pinching, and fine motor coordination. These bones work with joints, such as the interphalangeal joints and the metacarpophalangeal joints connecting to the hand bones. Tendons and muscles attach to the phalanges, enabling motions including flexion, extension, abduction, and adduction.
The bones allow for complex tasks like writing, typing, and manipulating small objects. In the feet, phalanges contribute to balance and stability, distributing weight during walking, running, or standing.
The toes, particularly the big toe, provide a firm base of support, assisting in maintaining equilibrium.