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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. It lie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothenar Eminence
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] |
Hypothenar Eminence
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] |
Median Nerve
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus. The median nerve originates from the lateral and medial cords of the brachial plexus, and has contributions from ventral roots of C5-C7 (lateral cord) and C8 and T1 (medial cord). The median nerve is the only nerve that passes through the carpal tunnel. Carpal tunnel syndrome is the disability that results from the median nerve being pressed in the carpal tunnel. Structure The median nerve arises from the branches from lateral and medial cords of the brachial plexus, courses through the anterior part of arm, forearm, and hand, and terminates by supplying the muscles of the hand. Arm After receiving inputs from both the lateral and medial cords of the brachial plexus, the median nerve enters the arm from the axilla at the inferior margin of the teres major muscle. It then passes vertically down and courses lateral to the brachial ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Nerve
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus. The median nerve originates from the lateral and medial cords of the brachial plexus, and has contributions from ventral roots of C5-C7 (lateral cord) and C8 and T1 (medial cord). The median nerve is the only nerve that passes through the carpal tunnel. Carpal tunnel syndrome is the disability that results from the median nerve being pressed in the carpal tunnel. Structure The median nerve arises from the branches from lateral and medial cords of the brachial plexus, courses through the anterior part of arm, forearm, and hand, and terminates by supplying the muscles of the hand. Arm After receiving inputs from both the lateral and medial cords of the brachial plexus, the median nerve enters the arm from the axilla at the inferior margin of the teres major muscle. It then passes vertically down and courses lateral to the brachial ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finger
A finger is a limb of the body and a type of digit, an organ of manipulation and sensation found in the hands of most of the Tetrapods, so also with humans and other primates. Most land vertebrates have five fingers ( Pentadactyly). Chambers 1998 p. 603 Oxford Illustrated pp. 311, 380 Land vertebrate fingers The five-rayed anterior limbs of terrestrial vertebrates can be derived phylogenetically from the pectoral fins of fish. Within the taxa of the terrestrial vertebrates, the basic pentadactyl plan, and thus also the fingers and phalanges, undergo many variations. Morphologically the different fingers of terrestrial vertebrates are homolog. The wings of birds and those of bats are not homologous, they are analogue flight organs. However, the phalanges within them are homologous. Chimpanzees have lower limbs that are specialized for manipulation, and (arguably) have fingers on their lower limbs as well. In the case of Primates in general, the digits of the hand a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opponens Pollicis
The opponens pollicis is a small, triangular muscle in the hand, which functions to oppose the thumb. It is one of the three thenar muscles. It lies deep to the abductor pollicis brevis and lateral to the flexor pollicis brevis. Structure The opponens pollicis muscle is one of the three thenar muscles. It originates from the flexor retinaculum of the hand and the tubercle of the trapezium. It passes downward and laterally, and is inserted into the whole length of the metacarpal bone of the thumb on its radial side. Innervation Like the other thenar muscles, the opponens pollicis is innervated by the recurrent branch of the median nerve. In 20% of the population, opponens pollicis is innervated by the ulnar nerve. Blood supply The opponens pollicis receives its blood supply from the superficial palmar arch. Function ''Opposition of the thumb'' is a combination of actions that allows the tip of the thumb to touch the tips of other fingers. The part of apposition that this musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints) are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking. Some evolutionary anatomists use the term ''hand'' to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand usually has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscles Of The Thumb
The muscles of the thumb are nine skeletal muscles located in the hand and forearm. The muscles allow for flexion, extension, adduction, abduction and opposition of the thumb. The muscles acting on the thumb can be divided into two groups: The extrinsic hand muscles, with their muscle bellies located in the forearm, and the intrinsic hand muscles, with their muscles bellies located in the hand proper. The muscles can be compared to guy-wires supporting a flagpole; tension from these muscular guy-wires must be provided in all directions to maintain stability in the articulated column formed by the bones of the thumb. Because this stability is actively maintained by muscles rather than by articular constraints, most muscles attached to the thumb tend to be active during most thumb motions. Extrinsic A ventral forearm muscle, the flexor pollicis longus originates on the anterior side of the radius distal to the radial tuberosity and from the interosseous membrane. It passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recurrent Branch Of The Median Nerve
The recurrent branch of the median nerve is the branch of the median nerve which supplies the thenar muscles. It is also occasionally referred to as the thenar branch of the median nerve, or the thenar muscular branch of the median nerve. Structure An earlier branch of the median nerve also supplies the lumbricals 1 & 2. All other intrinsic muscles of the hand receive their motor innervation from branches of the ulnar nerve. It usually passes distal to the transverse carpal ligament. It ends in the opponens pollicis. Function In the thenar eminence, the recurrent branch of the median nerve provides motor innervation to: * opponens pollicis muscle. * abductor pollicis brevis muscle. * the superficial part of flexor pollicis brevis muscle. Clinical significance The recurrent branch of the median nerve may be affected in carpal tunnel syndrome, or from its own separate peripheral neuropathies. Surgery The recurrent branch of the median nerve is also colloquially called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abductor Pollicis Brevis
The abductor pollicis brevis is a muscle in the hand that functions as an abductor of the thumb. Structure The abductor pollicis brevis is a flat, thin muscle located just under the skin. It is a thenar muscle, and therefore contributes to the bulk of the palm's thenar eminence. It originates from the flexor retinaculum of the hand, the tubercle of the scaphoid bone, and additionally sometimes from the tubercle of the trapezium. Running lateralward and downward, it is inserted by a thin, flat tendon into the lateral side of the base of the first phalanx of the thumb, and the capsule of the metacarpophalangeal joint. Nerve supply The abductor pollicis brevis is supplied by the recurrent branch of the median nerve (Roots C8-T1). Function Abduction of the thumb is defined as the movement of the thumb anteriorly, a direction perpendicular to the palm. The abductor pollicis brevis does this by acting across both the carpometacarpal joint and the metacarpophalangeal joint. It al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Pollicis Brevis
The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part. Origin and insertion The muscle's superficial head arises from the distal edge of the flexor retinaculum and the tubercle of the trapezium, the most lateral bone in the distal row of carpal bones. It passes along the radial side of the tendon of the flexor pollicis longus. The deeper (and medial) head "varies in size and may be absent." It arises from the trapezoid and capitate bones on the floor of the carpal tunnel, as well as the ligaments of the distal carpal row. Both heads become tendinous and insert together into the radial side of the base of the proximal phalanx of the thumb; at the junction between the tendinous heads there is a sesamoid bone.''Gray's Anatomy'' 1918, see infobox Innervation The superficial head is usually innervated by the lateral terminal branch of the median nerve. The deep part is often in ... [...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 adduct the thumb. It has two heads: transverse and oblique. It is a fleshy, flat, triangular, and fan-shaped muscle deep in the thenar compartment beneath the long flexor tendons and the lumbrical muscles at the center of the palm. It overlies the metacarpal bones and the 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 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 the adductor pollicis, is inserted into the ulnar side of the base of the proximal phalanx of the thu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
