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Human hand anatomy: tendons and ligaments, muscles, nerves in pictures with names

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Content

  1. Bones
  2. Wrist
  3. Metacarpus
  4. Fingers
  5. Sesamoid
  6. Ligamentous apparatus
  7. Wrist joint
  8. Carpometacarpal joints
  9. Metacarpophalangeal joints
  10. Interphalangeal joints
  11. Fibrous and synovial sheaths of the tendons of the fingers
  12. Muscle
  13. Middle group
  14. Thumb group
  15. Thumb group
  16. Nerves
  17. Hand Anatomy Videos

The hand is a complex anatomical structurecombining soft tissue and skeletal part. In the human hand, muscles, arteries, veins and nerves are branched and constantly intersected, and a network of ligaments and tendons responds to every command from the brain.

Bones

The human hand consists of 27 bones connected by ligaments and joints. This area contains many vessels and nerves that supply the hand with blood and innervate it. Interestingly, the arm muscles themselves are only partially involved in the movements of the fingers and hands. This is done by the muscles of the forearm, which transmit signals through long tendons attached to the fingers and wrist bones.Human hand anatomy: tendons and ligaments, muscles, nerves

The anatomy of the human hand is characterized by the following data:

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Carpal bones Distal row: large polygonal (Os trapezium), small polygonal (Os trapezoideum), capitate (Os capitatum), hook-shaped (Os hamatum).

Proximal row: scaphoid (Os scaphoideum), lunar (Os lunatum), triangular (Os triquetrum), pea-shaped (Os pisiforme).

Finger bones: proximal phalanx, distal, medial phalanx.

Metacarpal bones: long bones with a base, shaft and head.

Muscle Tenary.

Hypotensive.

Muscles of the palm

Finger and hand nerves The median nerve of the brachial plexus and its branches innervate the thenar muscles, palmaris longus, and finger flexors.

The radial nerve innervates the skin of some fingers.

The ulnar nerve and its branch innervate the muscles of the little finger, the ulnar flexor of the wrist, and other muscles in the hands.

Arteries All arteries originate from the brachial artery.
Veins All veins open into the radial or ulnar veins.
Wrist The wrist is capable of various movements (flexion, extension, abduction, adduction). Here is the carpal tunnel, through which the vessels, nerves and tendons from the forearm reach the hand.

The strength and firmness of the entire limb is provided by the carpal skeleton. The bones of the wrist are subdivided into the carpal, metacarpal, and phalanges of the fingers.

Wrist

The anatomy of the human hand includes the wrist-like structure, which, unlike the hand, does not have a radial structure. The skeleton of the wrist consists of 2 rows of bones, 4 in each. Row 1 contains the scaphoid and lunate bones, as well as the triangular and pisiform bones. They are located towards the forearm.

The second row is represented by the large and small trapezius, sternum and capitate bones, placed in the direction of the metacarpal bone.

All small bones are tightly held together by ligaments attached to the back and palmar sides of the hand. As a result, wrist mobility is minimized. On the inside of the strong transverse tendon band, there is a passageway for nerves that run from the forearm to the palm and provide joint movement and sensory perception. The wrist bones represent the articulation of both the metacarpal bones and the forearm.

Metacarpus

The metacarpal bones are adjacent to the wrist. They come after the 2nd row of carpal bones. Includes 5 tubular bones, numbered in Roman numerals from I to V, and form the palm. Between the first metacarpal bone (extending to the thumb) and the large polygonal there is a well-defined joint, thanks to which the thumb is opposed to all other fingers.Human hand anatomy: tendons and ligaments, muscles, nerves

This makes it indispensable for gripping and holding objects. The remaining 4 metacarpal bones are connected by strong ligaments to the wrist bones, and form an arch. If you clench your fist, you can clearly see the heads of the metacarpal bones in the form of spherical protrusions.

Fingers

The toes are composed of phalanges, or 14 separate elongated bones, which are divided as follows:

  • The thumb has 2 bones: the main and terminal.
  • The rest of the fingers consist of 3 bones: the main (proximal phalanx), middle (medial) and nail (distal).Human hand anatomy: tendons and ligaments, muscles, nerves

An exception is the thumb, which consists of the proximal and distal phalanx.

Sesamoid

These are small oval-shaped bones that resemble sesame seeds in appearance. They are found in tendons, primarily in the arms and legs, and are visible on x-rays. In most cases, the sesamoid bones are found in the joint of the thumb, index and little fingers, but their number in each joint varies depending on the sex.

Most people have 5 sesamoid bones in each hand:

  • The metacarpophalangeal joint of the thumb has 2 bones.
  • On the interphalangeal joint of the thumb - 1 bone.
  • On the metacarpophalangeal joint of the index finger on the radial side - 1 bone.
  • On the metacarpophalangeal joint of the little finger on the ulnar side - 1 bone.

The anatomy of the human hand in sections clearly represents the sesamoid bones. They lie in the thickness of the tendons in places where the tendons are thrown over the joints. These are the foot, knee joint, wrist. The presence and function of these structures has not yet been clarified, but there are several hypotheses, including both functional and phylogenetic ideas.

The functional hypothesis presents the idea that these bones increase the stress on the tendons in order to reduce friction and change the direction of muscle action, which increases grip strength and range movement. They are also thought to help stabilize the joints and strengthen the capsules.Human hand anatomy: tendons and ligaments, muscles, nerves

The phylogenetic hypothesis describes the presence of this structure, which originates from the time of development of the embryo. Sesamoid bones are a unique feature of the human body that still remains a mystery.

Ligamentous apparatus

While tendons connect muscle to bone, ligaments, thick bands of connective tissue, connect the joints of the hands. The stability of the wrist is provided by 6 main ligaments. They connect the bones of the wrist and radius together, as well as 2 different rows of bones in the wrist. Ligaments hold the bones in place while the wrist moves.

In addition to these small ligaments on the sides of the wrist, there are several larger ligaments called collateral ligaments. The ulnar and radial collateral ligaments function in the same way, providing stability to the wrist, tying the bones of the wrist together and preventing excessive movement.

  • The radial and ulnar collateral ligaments primarily provide support and function to the wrist, although they are aided by the smaller ligaments that surround them.
  • The posterior wrist ligaments support the back of the wrist.
  • Palmar ligaments support the lower part of the hand, providing palm-side stability to the wrist.

Two main bundles:

  • Collateral ulnar ligament of the thumb. Located on the inside of the finger joint, it is critical to its stability.
  • The scafolunate ligament connects the scaphoid to the lunate and provides basic hand and wrist stability.

The ligamentous apparatus provides flexibility, elasticity of the limb, movement, participates in the formation of joints.Human hand anatomy: tendons and ligaments, muscles, nerves

The joints of the hand are mostly articulated, but they also allow some translational and rotational movements.

Wrist joint

The wrist joint is located at the intersection of the radius of the first row of carpal bones. The condylar joint is the main joint of the wrist. It allows combined movements in several planes, including back and forth bending movements, side-to-side movements, and circular movements with a radius of no more than 10-12˚.

The table lists the main attachments and functions of the 4 primary external ligaments:

Ligaments Functions Characteristic
Dorsal wrist ligament Resists extreme bending Attaches between the radial and dorsal sides of the wrist bones.
Radial collateral ligament Resists the extreme manifestations of elbow deviation Strengthened by muscles such as the long abductor of the thumb and the short extensor of the thumb.
Palmar wrist ligament Resists excessive wrist extension The thickest wrist ligament has three parts.
Ulnar collateral ligament Gives stability to radial deflections Part of the elbow complex helps stabilize the distal radial joint.

Human hand anatomy: tendons and ligaments, muscles, nervesThe anatomy of the human hand joints shows that they are enclosed in a fibrous capsule, thickened by the external and internal ligaments. The proximal attachments of the external ligaments are outside the wrist bones, but attach distally within the wrist bones. In contrast, the internal ligaments have proximal and distal attachments.

Carpometacarpal joints

There are 5 carpometacarpal joints in total, of which the thumb joint is the most specialized and flexible. The other four are flat-type, sedentary synovial (synovial) joints that connect the 4 medial metacarpal bones. The joints are stable yet flexible enough to allow the palm to be folded into a cup or to grip an object during opposing movements with the thumb.

The four joints are surrounded and stabilized by a common fibrous capsule. It is lined with a synovial membrane that secretes viscous synovial fluid and acts as a lubricant.

The joints are stabilized by 3 sets of ligaments:

  • dorsal carpometacarpal ligaments;
  • palmar-carpal-metacarpal ligaments;
  • interosseous ligaments.

These soft tissue structures are actually thickenings of the fibrous joint capsule that surrounds the joints.

Metacarpophalangeal joints

The finger joints, formed by the heads of the metacarpal bones, are spherical. These are synovial joints of the condylloid type (allows the joint to move in 2 planes). On the sides of the joints are collateral ligaments that strengthen them.Human hand anatomy: tendons and ligaments, muscles, nerves

Promote spreading of the fingers, as well as squeeze and extend the fingers at the level of the joints.

Interphalangeal joints

Interphalangeal joints are a hinge-type synovial joint. These joints connect the phalanges together. The medial four fingers have two rows of interphalangeal joints, and the thumb has only one. Joints of this type allow only flexion and extension, for example, when a person signals someone to come up with his index finger.

Fibrous and synovial sheaths of the tendons of the fingers

Tendon sheaths facilitate the sliding of the muscle tendons. In the flexor of the fingers, the vagina is a fibrous-bone canal lined with a synovial membrane with segmental seals of fibrous tissue.

These fibrous bands or pulleys are:

  • the palmar aponeurosis pulley (formed by the transverse fibers of the palmar aponeurosis);
  • 5 annular pulleys and 3 cruciform pulleys. The second and fourth annular pulleys are the largest, thickest and most consistent in shape and pitch. The first, third and fifth annular pulleys have a less constant shape and a different angle of inclination than the cruciform pulleys.

Muscle

The anatomy of the human hand is a large, complex section that includes information about the muscles. The variety of movements that the arms are capable of is made possible by the special arrangement of many muscles within the arm. The structure of the arm includes the long and short carpal muscles. The long ones start from the forearm. The short ones are divided into the muscles of the palm, the pads of the little finger and the muscles of the pads of the thumb.Human hand anatomy: tendons and ligaments, muscles, nervesHuman hand anatomy: tendons and ligaments, muscles, nerves

Flexion of the wrist refers to a movement that pulls the palm downward. This action is carried out by the radial, ulnar flexor of the wrist, superficial, deep and long flexor of the thumb. In contrast, wrist extension reduces the angle of the back of the wrist.

The muscles responsible for this action:

  • Long radial extensor of the wrist.
  • The short radial extensor of the wrist, which moves the hand towards the thumb.
  • The extensor of the fingers, which also extends from the index finger to the little finger.
  • The minimal extensor of the fingers, which extends the little finger and brings the hand (moves the hand in the direction of the little finger).
  • The extensor ulnar of the wrist, which leads to the arm.

Other small muscles that cross the wrist joint can help extend the wrist, but only to a small extent.

Wrist supination is a rotation in which the palm is lifted up. The biceps brachii contributes to supination. Pronation is the opposite action, in which the wrist is turned with the palm down. In this case, the square pronator, the deep muscle in the anterior region, together with the round pronator, are involved.

On the surface of the palm, 2 muscle elevations are visible: hypotenar (near the little finger) and thenar (under the thumb). Here the muscles are divided into groups: the muscles of the small, thumb and middle group.

Middle group

The worm-like muscles, which have a thin cylindrical shape, emerge from the tendon of the great flexor, and then attach to the base of the proximal phalanges of 2-5 fingers, palmar and dorsal interosseous muscles.Human hand anatomy: tendons and ligaments, muscles, nerves

All muscles contribute to the flexion of the proximal digital phalanges, the ghost of the fingers to the middle finger, and spread them apart.

Thumb group

On the back of the hand you can see an elevation, thenaar.

It consists of muscles: abductor pollicis brevis, flexor pollicis brevis and opponens pollicis, flexor pollicis orevis, all of which are innervated by the median nerve.

  • The abductor short muscle abducts the thumb.
  • The flexor flexor of the thumb flexors the joint of the thumb.
  • The opposing muscle, opponens pollicis, opposes the thumb to the other fingers.
  • Adductor thumb muscle. It is located under the worm-like muscles and has 2 heads. The function is to bring the thumb to the index and bend it.

The thumb moves differently than other fingers due to its unique bone structure and special set of muscles. The muscles allow the thumb to be used for gestures and to oppose the position of the other fingers.

Thumb group

The hypotenar is in the palm of the hand below the little finger. It contains 3 muscles that are innervated by the deep branch of the ulnar nerve.

  • Abductor digiti minimi lifts the little finger.
  • The minimal flexor of the fingers flexes the little finger.
  • Opponens digiti minimi resists the little finger with the thumb.

Nerves

There are 3 main nerves in the hand and arms. They start at the shoulder and descend into the arms. Provides sensory information about objects that a person is touching and allows movement by contracting certain muscles.Human hand anatomy: tendons and ligaments, muscles, nerves

  1. Ulnar nerve starts from the cervical spine, passes under the collarbone down to the armpit, through the inner elbow and down into the arms. Part of the ulnar nerve runs along the forearm and is responsible for flexing the ring and little fingers, regulating the muscles located there. It also moves the muscles of the hypotenar.
  2. Radial nerve starts at the shoulder and runs along the back of the humerus. Activates the triceps muscle, which strengthens the elbow and is located in the upper arm. The radial nerve continues to move down the lateral side of the arm, outside the elbow, and down into the forearm, where it acts on the muscles that move the fingers and wrist. Transmits tactile sensations from the back of the hand and thumb to the brain.
  3. Median nerve begins in the cervical spine and runs under the collarbone to the elbow. The median nerve continues down the inside of the arm, adjacent to the brachial artery. Once the nerve has crossed the elbow, it begins to supply the pronator muscles and the flexors of the forearm, which allows the fingers to move. Responsible for skin perception on the palm, index, and the last finger.

The nerves of the fingertips are sensory cells through which a person perceives the world through touch, so they are sensitive to pain. They are the terminal branches of the median and ulnar nerves. Although anatomical variability exists, the median nerve innervates the palmar part of the thumb, index, middle and the radial half of the ring finger, while the ulnar half of the ring finger and little finger are innervated by the terminal branches ulnar nerve.

The main nerve branches inside the fingers are called "the actual digital nerves" and are further referred to as radial or ulnar, depending on which half of the finger is described. The radial nerve provides sensitivity to the dorsum of the hand and fingers.

The normal function of the human hand has its own anatomical features. This is the result of not only a complex and versatile block diagram, but also a combinational and fully automatic control system.

Hand Anatomy Videos

Anatomy of the joints and ligaments of the hand:

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