Victor Forge
The human hand is an intricate network of bones, muscles, nerves, connective tissue, and blood vessels. There are 27 bones in each hand, including 14 phalanges (finger bones). The fingers have three joints each, which can only be bent and stretched in one direction. The thumb is the only digit that can twist. The muscles that move the finger joints are in the palm and forearm. Tendons, which are like strong, flexible ropes, connect muscles to bones. The hand and wrist have two groups of tendons: extensor tendons, which help extend and straighten the fingers, and flexor tendons, which help flex and curl the fingers.
| Characteristics | Values |
|---|---|
| Are there muscles in fingers? | No, fingers do not contain muscles (other than arrector pili). The muscles that move the finger joints are in the palm and forearm. |
| Number of bones in each finger | 3 |
| Number of bones in the thumb | 2 |
| Number of bones in each hand | 19 |
| Number of phalanges in each hand | 14 |
| Number of metacarpal bones in each hand | 5 |
| Number of carpals in each hand | 8 |
| Number of muscles in the hand | Over 30 |
| Number of muscles in the forearm | 18 |
| Number of muscles in the palm | 17 |
| Number of tendons in the hand | 9 |
| Number of ligaments in the hand | 4 |
| Number of nerves in the hand | 3 |
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What You'll Learn
- Fingers have no muscles, but they are moved by muscles in the forearm and palm
- Tendons connect muscles to bones and allow movement
- There are two types of tendons: extensor and flexor
- The muscles that close the hand are called flexors, and extensors open the hand
- The hand is made up of phalanges, metacarpals, and carpals
Fingers have no muscles, but they are moved by muscles in the forearm and palm
The human hand is an intricate part of the body, with numerous bones, muscles, and ligaments working together to enable movement and dexterity. While the hand as a whole contains many muscles, the fingers themselves do not. Instead, the fingers are moved by muscles located in the forearm and palm.
The fingers are controlled by tendons, which are strong, flexible structures that connect muscles to bones. These tendons deliver motion from the forearm muscles to the fingers, allowing for a wide range of movements. The muscles in the forearm that control finger movement are called the extensor and flexor muscles. The extensors are located on the back of the forearm and help to straighten the fingers. On the other hand, the flexors are located on the underside of the forearm and enable the bending of the fingers.
The tendons from the extensor and flexor muscles run through the back of the hand and the palm, respectively, to reach the fingers. In the hand, there are also short muscles located between the metacarpal bones, which help spread the fingers apart (abduction) and pull them back together (adduction). Additionally, the hand contains two groups of more powerful muscles: the thenar eminence, which is at the base of the thumb, and the hypothenar eminence, which controls the movement of the little finger.
The muscles in the forearm and palm that control finger movement are innervated by the radial, median, and ulnar nerves. These nerves enable the transmission of signals from the brain to the muscles, instructing them to contract and relax, ultimately resulting in the movement of the fingers. The complex interplay between muscles, tendons, nerves, and bones allows for the remarkable dexterity and functionality of the human hand.
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Tendons connect muscles to bones and allow movement
The human hand is composed of various bones, muscles, and ligaments that work together to allow for a wide range of movement and dexterity. There are three types of bones in the hand: phalanges in the fingers, metacarpals in the mid-hand, and carpals in the wrist. Each finger has three phalanges (the distal, middle, and proximal), except for the thumb, which has two. Tendons, which are made of fibrous connective tissue, play a crucial role in connecting muscles to bones and enabling movement.
Tendons are found throughout the body, including in the elbow, heel, knee, shoulder, and wrist. They come in different shapes and sizes, depending on the muscles they attach to. Wider and shorter tendons usually connect to muscles that generate a lot of force, while thinner and longer tendons typically connect to muscles that perform more delicate movements. Tendons are composed primarily of collagen, a strong and flexible protein that is resistant to damage.
In the hand, tendons unite with muscles and bones to facilitate movement. For example, the fingers have two long flexors located on the underside of the forearm, which insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx, allowing the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group, which includes the opponens and abductor brevis muscles. These muscles enable the thumb to move in opposition to the other fingers, making grasping possible.
The extensors, located on the back of the forearm, are connected in a more complex way to the dorsum of the fingers. Their primary function is to straighten out the digits. The thumb has two extensors in the forearm, and the index finger and little finger have an extra extensor for pointing. The muscles of the hand are innervated by the radial, median, and ulnar nerves, which coordinate their movement.
The hand also contains ligaments, which are fibrous tissues that help bind together the joints in the hand, and sheaths, which are tubular structures that surround part of the fingers. These components work together with the tendons and muscles to provide the hand with its remarkable dexterity and range of motion.
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There are two types of tendons: extensor and flexor
The human hand is composed of various bones, muscles, and ligaments that enable a large range of movement and dexterity. There are muscles in the fingers, and there are two types of tendons in the fingers: extensor and flexor.
The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm, and the tendons of these form the anatomical snuff box. The index finger and the little finger have an extra extensor, used for pointing, for instance. The extensors are situated within six separate compartments. The first four compartments are located in the grooves on the dorsum of the inferior side of the radius, while the fifth compartment is between the radius and ulna. The sixth compartment is in the groove on the dorsum of the inferior side of the ulna. The muscles of the hand are innervated by the radial, median, and ulnar nerves. The radial nerve innervates the finger extensors and the thumb abductor, which are the muscles that extend at the wrist and metacarpophalangeal joints (knuckles) and abduct and extend the thumb. The median nerve innervates the flexors of the wrist and digits, the abductors and opponens of the thumb, and the first and second lumbricals.
The fingers have two long flexors, located on the underside of the forearm. They insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx. The flexors allow for the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group. The human thumb also has other muscles in the thenar group (opponens and abductor brevis muscle), moving the thumb in opposition, making grasping possible. The flexor tendon injuries are common and usually result from a laceration-type injury. These injuries are clinically challenging as they cannot heal without surgical treatment. The procedure involves bringing the two ends of the broken tendon back together for healing to occur.
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The muscles that close the hand are called flexors, and extensors open the hand
The human hand is composed of a wrist, palm, and five fingers. It is made up of many different bones, muscles, and ligaments that allow for a large amount of movement and dexterity. The muscles are the structures that contract, enabling the movement of bones.
The muscles that close the hand are called flexors, and they are located on the underside of the forearm. The flexors of the hand and wrist are on the anterior side of the forearm. The fingers have two long flexors that insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx. The flexors allow for the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group. The human thumb also has other muscles in the thenar group (opponens and abductor brevis muscle), which enable grasping.
The muscles that open the hand are called extensors, and they are located on the back of the forearm. The extensors of the hand and wrist are on the posterior side of the forearm. The extensors are connected in a more complex way than the flexors to the dorsum of the fingers. The tendons of the extensors unite with the interosseous and lumbrical muscles to form the extensorhood mechanism. The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm, and the tendons of these form the anatomical snuff box. The index finger and the little finger have an extra extensor, used for pointing, for example.
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The hand is made up of phalanges, metacarpals, and carpals
The human hand is a complex structure made up of many different bones, muscles, ligaments, tendons, and sheaths, all working together to allow for a wide range of movement and dexterity.
The hand consists of 27 bones, divided into three types: phalanges, metacarpals, and carpals. The phalanges are the 14 finger bones, with each finger having three phalanges (distal, middle, and proximal), except for the thumb, which has two. The metacarpals are the five bones that make up the middle part of the hand, with each one related to a specific digit. The carpals are the eight irregularly shaped wrist bones, which are often split into two rows, with the proximal row articulating with the metacarpals and the distal row forming an arch.
The hand also contains numerous muscles, which are groups of cells that contract and relax, allowing for movement. Some of the muscles in the hand include the interossei muscles, which allow us to spread and pull our fingers together, the thenar muscle group, which is involved in moving the thumb, and the lumbrical muscles, which help straighten the fingers. Tendons connect the muscles to the bones, and along with ligaments and sheaths, enable the hand to move in a variety of ways.
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Frequently asked questions
No, there are no muscles in the fingers (other than arrector pili). The muscles that move the finger joints are in the palm and forearm.
The muscles that close the hand are called flexors, and the ones that open the hand are called extensors. The muscles in the forearm that control finger movement include the flexor digitorum profundus and the biceps.
The flexors allow for the bending of the fingers, while the extensors straighten them out. The extensors are located on the back of the forearm and are connected to the dorsum of the fingers.
There are 34 muscles in each hand, including the thenar, hypothenar, interossei, and lumbrical muscles. The thenar muscles control the thumb, while the hypothenar muscles line the outer edges of the palm on the outside of the pinkie finger. The interossei muscles help the fingers move side-to-side, and the lumbrical muscles help flex the fingers.
The hand and wrist contain bones, tendons, ligaments, nerves, blood vessels, and connective tissue. The bones of the hand include phalanges, metacarpals, and carpals. The tendons connect the muscles to the bones, and the ligaments help bind the joints together.
