Digitus tertius

Digitus tertius

Latin	Digitus tertius manus
Nerve	Median nerve, Ulnar nerve
System	Skeletal, Muscular

Digitus tertius, commonly known as the middle finger or the third finger, is the third digit of the human hand, located between the index finger and the ring finger. It is typically the longest finger on the hand and is often used in gestures and for manipulating objects.

Structure

The digitus tertius consists of three phalanges: the proximal, middle, and distal. These bones are connected by two interphalangeal joints: the proximal interphalangeal joint (PIP) and the distal interphalangeal joint (DIP). The finger is supported by various muscles, tendons, and ligaments, which facilitate movement and provide stability.

Musculature

The primary muscles involved in the movement of the digitus tertius include:

• Flexor digitorum superficialis and Flexor digitorum profundus - responsible for flexing the finger.
• Extensor digitorum - responsible for extending the finger.
• Lumbricals and interossei - assist in flexion, extension, and adduction of the finger.

Innervation

The digitus tertius is primarily innervated by the median nerve, with contributions from the ulnar nerve for certain muscle functions and skin sensation.

Vascular supply

Blood supply to the digitus tertius is provided by the proper palmar digital arteries and dorsal digital arteries, branches of the radial artery and ulnar artery.

Function

The digitus tertius is crucial for hand function, contributing to grip strength and precision handling of tools and objects. Its length and positioning allow for significant leverage and force application during tasks.

Cultural and social aspects

The middle finger has various cultural significances and is often used in gestures. In many cultures, extending the middle finger alone is considered an offensive gesture.

Clinical significance

Injuries to the digitus tertius can include fractures, dislocations, tendon injuries, and nerve damage. Treatment depends on the severity and type of injury but may involve splinting, surgery, and rehabilitation.

See also

• Hand
• Finger
• Phalanges
• Human skeleton