Complete Guide to Finger Anatomy with Parts, Names & Diagram

Overview of Finger Anatomy

Fingers are highly specialized structures found in the hands of most tetrapods, including humans and primates. Over millions of years of evolution, they have adapted to perform tasks with precision and skill. Each finger comprises three small bones called phalanges, which give the finger its shape and strength. These bones are connected by joints and surrounded by a network of muscles, tendons, and ligaments, which allows smooth and coordinated movement. Tendons connect muscles to bones, helping fingers bend, grip, and release objects. Ligaments hold joints in place, while nerves allow you to feel things like pressure, temperature, and texture. Blood vessels supply the tissues with the nutrients they need to work properly. These parts work together to enable delicate tasks like writing and stronger actions like gripping during physical activities.

In this article, we will examine the anatomy of the finger, including its different parts and functions, to get detailed information about the fingers.

Finger Anatomy Diagram

Parts of the Finger

Muscles

Flexor Digitorum Profundus
Flexor Digitorum Superficialis
Extensor Digitorum
Lumbricals
Interossei

Joints

Metacarpophalangeal (MCP) Joint
Proximal Interphalangeal (PIP) Joint
Distal Interphalangeal (DIP) Joint

Tendons

Flexor Digitorum Profundus
Flexor Digitorum Superficialis
Flexor Pollicis Longus
Extensor Digitorum

Ligaments

Collateral ligaments
Volara plate
Palmar ligaments
Dorsal ligaments
Sagittal bands

Finger Parts

Nail
Phalanx bones
Blood vessels
Nerves
Pulp
Sesamoid bones

Finger Anatomy: Joint

The finger joints allow the performing of various movements with precision and accuracy. These joints are necessary for bending, straightening, twisting, and grasping objects.

Metacarpophalangeal (MCP) Joint

The bottom part of the pinky finger connects to the head of the fifth metacarpal bone, forming the metacarpophalangeal (MCP) joint. It can bend, flex, twist, turn, and move in various directions.

This joint is kept together by some tough ligaments and lubricated by a smooth substance called synovial fluid.

Proximal Interphalangeal (PIP) Joint

This joint is located in the middle of your finger and can only move in one direction – bending or straightening.

The joint plays a crucial role in gripping and grasping objects. The surrounding tough ligaments provide stability and prevent injury.

Distal Interphalangeal (DIP) Joint

It is a tiny joint at the tip of your finger. This joint might be small and move in one direction.

This joint is essential for all intricate finger movements, from playing musical instruments to typing on a keyboard.

Finger Anatomy: Tendon

Flexor Digitorum Profundus

FDP tendons help bend the fingers at the fingertip joint. The same muscles regulate them as the rest of the fingers. This muscle is divided into four tendons that go down the forearm via the carpal tunnel and finally join to the fingertip bone.

In contrast to other flexors in the hand, these tendons travel within protective sheaths along the hand and fingers near the bone.

Flexor Digitorum Superficialis

FDS tendons play a vital role in bending the middle joints of the index, middle, ring, and little fingers. A shared muscle powers them, split into four tendons from the forearm into the carpal tunnel. They smoothly slide in sheaths along the fingers and hands.

At the finger level, each tendon separates into two cords. Independently enter the middle bone on either side of the flexor digitorum profundus tendon and continue down to the finger. This intricate system ensures coordinated and efficient finger movement.

Extensor Digitorum Communis

The EDC (Extensor Digitorum Communis) tendons extend from the forearm to your fingertips. Their primary responsibility is straightening the index, middle, ring, and little fingers.

They run down the forearm, passing through the retinaculum, which keeps them in place. These tendons work together to expand the fingers’ joints, providing for smooth and coordinated movement.

Extensor Digiti Minimi Tendon

The EDM muscle is crucial for straightening the little finger. Located in the forearm, it works with another muscle to control the small finger’s movement. Its tendon passes through a wristband (retinaculum) for support, allowing smooth movement.

Surprisingly, fewer than half of people have this tendon. The EDM and other tendons ensure the straightening of the three joints in the small finger.

Finger Anatomy: Ligaments

Collateral Ligaments

The collateral ligaments on each side of the finger joint are made of tough, highly organized collagen fibers. This structure gives them strength and flexibility to handle the various activities of the fingers. These ligaments serve a dual purpose:

Support precise finger movements to enable us to perform fine motor tasks easily.
Protect the joint by stabilizing it against unwanted forces.

Volara Plate

The volar plate ligament is found on the palm side of the finger joints. It is made up of specialized collagen fibers and glycosaminoglycans. This ligament has unique properties that provide strength and flexibility.

Its primary role is stabilizing the finger joint and protecting the flexor tendons responsible for bending the fingers.

The volar plate absorbs and distributes forces during movement, acting as a cushion to prevent excessive joint extension, which helps safeguard the joint from injury. Its strength and elasticity make it crucial for maintaining normal finger function.

Palmar & Dorsal Ligaments

The palmar and dorsal ligaments play a crucial role in finger movement. The palmar ligaments are located on the palm side of the finger and are essential in preventing joint hyperextension.

These ligaments are highly organized collagen fibers that provide strength and stability to the joint. On the other hand, the dorsal ligaments are located on the backside of the finger. They are crucial in preventing excessive joint movement.

Sagittal Bands

The sagittal bands are another remarkable set of ligaments found in the fingers. These bands are located on the top of the finger and are crucial in facilitating finger movement.

Finger Anatomy: Parts

Nail

Nails and toenails are like skin accessories, made of tough keratin about half a millimeter thick. They’re firmly attached to the nail bed but have a slight gap at the tip for practical uses like scratching. Nails are essential for our sense of touch.

The lateral folds on each side of the nail give a neat framing effect. The proximal fold is at the base of the nail, acting as a skin border.

A thin layer of skin called the cuticle covers this area. Altogether, our nails are fascinating structures with unique features.

Phalanx Bones

The phalanges are small bones that make up the fingers. Even though they are tiny, they are classified as long bones because of their structure. Each phalange has a central shaft, a base at one end, and a head at the other.

In total, there are fourteen phalanges in each hand. The four fingers (index, middle, ring, and little fingers) have three phalanges each—called the proximal, middle, and distal phalanges. The thumb is slightly different, as it only has the proximal and distal phalanges.

These bones are joined by interphalangeal joints, which allow the fingers to move. Blood is supplied to the phalanges through the palmar digital arteries, which send nutrients to the bones via small branches called nutrient rami.

Skin

The function of the skin is to protect, regulate temperature, and feel sensations. The outer layer (epidermis) shields and gives color. In contrast, the inner layer (dermis) has fibers for strength, glands, hair follicles, and nerves.

Below is the fatty layer (subcutis), providing insulation and energy storage. Together, they defend against harm, control body temperature, and allow us to feel pain and pleasure. The skin stays functional by constantly replacing old cells with new ones.

Complete Guide to Finger Anatomy with Parts, Names, Functions & Diagram