Digitus quartus

Digitus quartus

Latin	Digitus quartus manus, Digitus IV
Nerve	Fourth common palmar digital nerves
System	Skeletal and muscular system

Digitus quartus or the fourth digit of the hand, commonly referred to as the ring finger, is one of the five digits of the human hand. It is located between the third digit (middle finger) and the fifth digit (little finger). The ring finger has unique social and cultural significances in many societies, particularly in the context of wearing wedding rings.

Structure

The structure of the digitus quartus, like other fingers, consists of three types of bones: the phalanges - proximal, middle, and distal. These bones are connected by joints and ligaments, allowing for a range of movements. The finger is also associated with specific muscles and tendons that facilitate movement and provide strength and flexibility.

Musculature

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

• Flexor digitorum superficialis - responsible for flexing the proximal and middle phalanges.
• Flexor digitorum profundus - flexes the distal phalanx.
• Extensor digitorum - extends all the phalanges of the finger.

Nerve Supply

The nerve supply to the digitus quartus is primarily provided by the ulnar nerve and the median nerve. These nerves ensure sensation and motor control to the finger.

Vascular Supply

The blood supply to the ring finger is through the fourth common palmar digital arteries, branches of the palmar arches.

Function

The digitus quartus plays a crucial role in hand function, contributing to grip strength and precision tasks. It works in coordination with the other fingers to perform complex motions required for daily activities.

Cultural and Social Aspects

The ring finger is often used in many cultures for the placement of wedding rings—a tradition that symbolizes marriage and commitment. The choice of this finger is historically believed to be connected to the idea that it contains a vein that leads directly to the heart, although this belief is anatomically inaccurate.

Clinical Significance

Conditions affecting the digitus quartus can impact hand function significantly. Common issues include:

• Trigger finger
• Fractures
• Arthritis
• Tendonitis

See Also

• Hand
• Finger
• Phalanx (bone)
• Tendon
• Muscle