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Muscles Of The Hand
The muscles of the hand are the skeletal muscles responsible for the movement of the hand and Digiti manus, fingers. The muscles of the hand can be subdivided into two groups: the extrinsic and intrinsic muscle groups. The extrinsic muscle groups are the long List of flexors of the human body, flexors and List of extensors of the human body, extensors. They are called extrinsic because the muscle belly is located on the forearm. The intrinsic group are the smaller muscles located within the hand itself. The muscles of the hand are innervated by the Radial nerve, radial, Median nerve, median, and ulnar nerves from the brachial plexus. Intrinsic The intrinsic muscle groups are the thenar (thumb) and hypothenar (little finger) muscles; the interossei muscles (dorsal interossei of the hand, four dorsally and palmar interossei muscles, three volarly) originating between the metacarpal bones; and the lumbricals of the hand, lumbrical muscles arising from the flexor digitorum profund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Extremity
The upper Limb (anatomy), limbs or upper extremities are the forelimbs of an upright posture, upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digit (anatomy), digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the shoulder, arm, elbow, forearm, wrist and hand, and is primarily used for climbing, manual handling of loads, lifting and dexterity, manipulating objects. In anatomy, just as arm refers to the upper arm, leg refers to the lower leg. Definition In formal usage, the term "arm" only refers to the structures from the shoulder to the elbow, explicitly excluding the forearm, and thus "upper limb" and "arm" are not synonymous. However, in casual usage, the terms are often used interchangeably. The term "upper arm" is redundant in anatomy, but in informal usage is used to distinguish between the two terms. Structure I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Flexors Of The Human Body
In anatomy, flexor is a muscle that contracts to perform flexion (from the Latin verb ''flectere'', to bend), a movement that decreases the angle between the bones converging at a joint. For example, one's elbow joint flexes when one brings their hand closer to the shoulder, thus decreasing the angle between the upper arm and the forearm. Flexors Upper limb *of the humerus bone (the bone in the upper arm) at the shoulder ** Pectoralis major **Anterior deltoid ** Coracobrachialis **Biceps brachii * of the forearm at the elbow ** Brachialis **Brachioradialis **Biceps brachii *of carpus (the carpal bones) at the wrist **flexor carpi radialis **flexor carpi ulnaris ** palmaris longus *of the hand ** flexor pollicis longus muscle ** flexor pollicis brevis muscle **flexor digitorum profundus muscle **flexor digitorum superficialis muscle Lower limb Hip The hip flexors are (in descending order of importance to the action of flexing the hip joint):Platzer (2004), p 246 *Collectively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adductor Pollicis
In human anatomy, the adductor pollicis muscle is a muscle in the hand that functions to Adduction, adduct the thumb. It has two heads: transverse and oblique. It is a fleshy, flat, triangular, and fan-shaped muscle deep in the Thenar eminence, thenar compartment beneath the long flexor tendons and the Lumbricals of the hand, lumbrical muscles at the center of the palm. It overlies the Metacarpus, metacarpal bones and the Palmar interossei muscles, interosseous muscles. Structure Oblique head The oblique head (Latin: ''adductor obliquus pollicis'') arises by several slips from the capitate bone, the bases of the second and third metacarpus, metacarpals, the intercarpal ligaments, and the sheath of the tendon of the flexor carpi radialis. Gray's Anatomy 1918. (See infobox) From this origin the greater number of fibers pass obliquely downward and converge to a tendon, which, uniting with the tendons of the medial portion of the flexor pollicis brevis and the transverse head of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmaris Brevis
Palmaris brevis muscle is a thin, quadrilateral muscle, placed beneath the integument of the ulnar side of the hand. It acts to fold the skin of the hypothenar eminence transversally. Structure Origin and insertion Palmaris brevis muscle is located on the ulnar side of the hand. It arises from the tendinous fasciculi from the transverse carpal ligament and palmar aponeurosis. The muscle fibres are inserted into the skin on the ulnar border of the palm of the hand, and occasionally on the pisiform bone. Innervation Palmaris brevis muscle is the only muscle innervated by the superficial branch of the ulnar nerve (C8, T1). Blood supply Palmaris brevis muscle is supplied by the palmar metacarpal artery of the deep palmar arch. Discovery The first recorded observation of the muscle is by Italian anatomist Giambattista Canano sometime before 1543. The muscle was independently discovered a few years later by Realdo Colombo before being pushed to general acceptance in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Digitorum Profundus Muscle
The flexor digitorum profundus or flexor digitorum communis profundus is a muscle in the forearm of humans that flexes the fingers (also known as digits). It is considered an extrinsic hand muscle because it acts on the hand while its muscle belly is located in the forearm. Together the flexor pollicis longus, pronator quadratus, and flexor digitorum profundus form the deep layer of ventral forearm muscles.Platzer 2004, p 162 The muscle is named . Structure Flexor digitorum profundus originates in the upper 3/4 of the anterior and medial surfaces of the ulna, interosseous membrane and deep fascia of the forearm. The muscle fans out into four tendons (one to each of the second to fifth fingers) to the palmar base of the distal phalanx. Along with the flexor digitorum superficialis, it has long tendons that run down the arm and through the carpal tunnel and attach to the palmar side of the phalanges of the fingers. Flexor digitorum profundus lies deep to the superfici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbricals Of The Hand
The lumbricals are intrinsic muscles of the hand that flexion, flex the metacarpophalangeal joints, and extension (kinesiology), extend the Interphalangeal articulations of hand, interphalangeal joints. p. 97 The lumbrical muscle of the foot, lumbrical muscles of the foot also have a similar action, though they are of less clinical concern. Structure The lumbricals are four, small, worm-like muscles on each hand. These muscles are unusual in that they do not attach to bone. Instead, they attach proximally to the tendons of flexor digitorum profundus, and distally to the extensor expansions. The first and second lumbricals are Anatomical terms of muscle, unipennate, while the third and fourth lumbricals are Anatomical terms of muscle, bipennate. Nerve supply The first and second lumbricals (the most radial two) are Nerve, innervated by the median nerve. The third and fourth lumbricals (most ulnar two) are innervated by the deep branch of ulnar nerve. This is the usual inne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metacarpal Bone
In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones ( wrist bones), which articulate with the forearm. The metacarpal bones are homologous to the metatarsal bones in the foot. Structure The metacarpals form a transverse arch to which the rigid row of distal carpal bones are fixed. The peripheral metacarpals (those of the thumb and little finger) form the sides of the cup of the palmar gutter and as they are brought together they deepen this concavity. The index metacarpal is the most firmly fixed, while the thumb metacarpal articulates with the trapezium and acts independently from the others. The middle metacarpals are tightly united to the carpus by intrinsic interlocking bone elements at their bases. The ring metacarpal is somewhat more mobile while the fifth metacarpal is semi-independent.Tubiana ''et al'' 1998, p 11 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmar Interossei Muscles
In human anatomy, the palmar or volar interossei (interossei volares in older literature) are four muscles, one on the thumb that is occasionally missing, and three small, unipennate, central muscles in the hand that lie between the Metacarpus, metacarpal bones and are attached to the Index finger, index, Ring finger, ring, and Little finger, little fingers. They are smaller than the dorsal interossei of the hand. Structure All palmar interossei originate along the shaft of the metacarpal bone of the digit on which they act. They are inserted into the base of the Phalanx bone, proximal phalanx and the extensor expansion of the Extensor digitorum muscle, extensor digitorum of the same digit. Pollical palmar interosseous The first palmar interosseous is located at the thumb's medial side. Passing between the first dorsal interosseous and the oblique head of Adductor pollicis muscle, adductor pollicis, it is inserted on the base of the thumb's proximal phalanx together with Adductor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Interossei Of The Hand
In human anatomy, the dorsal interossei (DI) are four muscles in the back of the hand that act to abduct (spread) the index, middle, and ring fingers away from the hand's midline (ray of middle finger) and assist in flexion at the metacarpophalangeal The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow ... joints and extension at the interphalangeal joints of the index, middle and ring fingers. Structure There are four dorsal interossei in each hand. They are specified as 'dorsal' to contrast them with the palmar interossei, which are located on the anterior side of the metacarpals. The dorsal interosseous muscles are bipennate, with each muscle arising by two heads from the adjacent sides of the metacarpal bones, but more extensively from the metacarpal bone of the finger into whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Finger
The little finger or pinkie, also known as the baby finger, fifth digit, or pinky finger, is the most ulnar and smallest digit of the human hand, and next to the ring finger. Etymology The word "pinkie" is derived from the Dutch word ''pink'', meaning "little finger". The earliest recorded use of the term "pinkie" is from Scotland in 1808. The term (sometimes spelled "pinky") is common in Scottish English and American English, and is also used extensively in other Commonwealth countries such as New Zealand, Canada, and Australia. Nerves and muscles There are nine muscles that control the fifth digit: Three in the hypothenar eminence, two extrinsic flexors, two extrinsic extensors, and two more intrinsic muscles: * Hypothenar eminence: ** Opponens digiti minimi muscle ** Abductor minimi digiti muscle (adduction from third palmar interossei) ** Flexor digiti minimi brevis (the "longus" is absent in most humans) * Two extrinsic flexors: ** Flexor digitorum superficialis ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothenar
The hypothenar muscles are a group of three muscles of the hand, palm that control the motion of the little finger. The three muscles are: * Abductor minimi digiti muscle (hand), Abductor digiti minimi * Flexor digiti minimi brevis (hand), Flexor digiti minimi brevis * Opponens digiti minimi Structure The muscles of hypothenar eminence are from medial to lateral: * Opponens digiti minimi muscle, Opponens digiti minimi * Flexor digiti minimi brevis muscle (hand), Flexor digiti minimi brevis * Abductor digiti minimi muscle of hand, Abductor digiti minimi The intrinsic muscles of hand can be remembered using the mnemonic, "A OF A OF A" for, Abductor pollicis brevis, Opponens pollicis, Flexor pollicis brevis (the three thenar muscles), Adductor pollicis, and the three hypothenar muscles, Opponens digiti minimi, Flexor digiti minimi brevis, Abductor digiti minimi. Clinical significance "Hypothenar atrophy" is associated with the lesion of the ulnar nerve, which supplies the three hyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thenar
The thenar eminence is the mound formed at the base of the thumb on the palm of the hand by the intrinsic group of muscles of the thumb. The skin overlying this region is the area stimulated when trying to elicit a palmomental reflex. The word thenar comes . Structure The following three muscles are considered part of the thenar eminence: * Abductor pollicis brevis abducts the thumb. This muscle is the most superficial of the thenar group. * Flexor pollicis brevis, which lies next to the abductor, will flex the thumb, curling it up in the palm. (The flexor pollicis longus, which is inserted into the distal phalanx of the thumb, is not considered part of the thenar eminence.) * Opponens pollicis lies deep to abductor pollicis brevis. As its name suggests it opposes the thumb, bringing it against the fingers. This is a very important movement, as most of human hand dexterity comes from this action. Another muscle that controls movement of the thumb is adductor pollicis. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
