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Cervical Spinal Nerve 8
The cervical spinal nerve 8 (C8) is a spinal nerve of the cervical segment. It originates from the spinal column from below the cervical vertebra 7 (C7). Innervation The C8 nerve forms part of the radial and ulnar nerves via the brachial plexus, and therefore has motor and sensory function in the upper limb. Sensory The C8 nerve receives sensory afferents from the C8 dermatome. This consists of all the skin on the little finger, and continuing up slightly past the wrist on the palmar and dorsal aspects of the hand and forearm.Drake et al. Gray's Anatomy for Students. Second Edition (2010). Clinically, a test of the pad of the little finger is often used to assess C8 integrity.Aland et al. University of Queensland School of Medicine Clinical Skills Handbook 2010 Motor The C8 nerve contributes to the motor innervation of many of the muscles in the trunk and upper limb. Its primary function is the flexion of the fingers, and this is used as the clinical test for C8 inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Spinal Nerve
A spinal nerve is a mixed nerve, which carries Motor neuron, motor, Sensory neuron, sensory, and Autonomic nervous system, autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical vertebrae, cervical, thoracic vertebrae, thoracic, lumbar vertebrae, lumbar, sacral vertebrae, sacral and coccygeal vertebrae, coccygeal regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system. Structure Each spinal nerve is a mixed nerve, formed from the combination of nerve root axon, fibers from its Dorsal root of spinal nerve, dorsal and Ventral root of spinal nerve, ventral roots. The dorsal root is the afferent nerve fiber, afferent sensory root and carries sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Thoracodorsal Nerve
The thoracodorsal nerve is a nerve present in humans and other animals, also known as the middle subscapular nerve or the long subscapular nerve. It supplies the latissimus dorsi muscle. Anatomy Origin The thoracodorsal nerve arises from the posterior cord of the brachial plexus. It is derived from their ventral rami (in spite of the fact that the latissimus dorsi is found in the back) of cervical nerves C6-C8. It is derived from fibres of the posterior divisions of all three trunks of the brachial plexus. Course It passes inferior-ward anterior to the subscapularis muscle and subscapular vessels. It penetrates into the substance of the latissimus dorsi muscle near the lateral border of scapula. It follows the course of the subscapular artery, along the posterior wall of the axilla to the latissimus dorsi muscle, in which it may be traced as far as the lower border of the muscle. Distribution The thoracodorsal nerve innervates the latissimus dorsi muscle on its deep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Extensor Digiti Minimi
The extensor digiti minimi (extensor digiti quinti proprius) is a slender muscle of the forearm, placed on the ulnar side of the extensor digitorum communis, with which it is generally connected. It arises from the common extensor tendon by a thin tendinous slip and frequently from the intermuscular septa between it and the adjacent muscles. Its tendon passes through a compartment of the extensor retinaculum, posterior to distal radio-ulnar joint, then divides into two as it crosses the dorsum of the hand, and finally joins the extensor digitorum tendon. All three tendons attach to the dorsal digital expansion of the fifth digit (little finger). There may be a slip of tendon to the fourth digit. Variations * An additional fibrous slip from the lateral epicondyle: The tendon of insertion may not divide or may send a slip to the ring finger The ring finger, third finger, fourth finger, leech finger, or annulary is the fourth digit of the human hand, located between the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Extensor Digitorum
The extensor digitorum muscle (also known as extensor digitorum communis) is a muscle of the posterior forearm present in humans and other animals. It extends the medial four digits of the hand. Extensor digitorum is innervated by the posterior interosseous nerve, which is a branch of the radial nerve. Structure The extensor digitorum muscle arises from the lateral epicondyle of the humerus, by the common tendon; from the intermuscular septa between it and the adjacent muscles, and from the antebrachial fascia. It divides below into four tendons, which pass, together with that of the extensor indicis proprius, through a separate compartment of the dorsal carpal ligament, within a mucous sheath. The tendons then diverge on the back of the hand, and are inserted into the middle and distal phalanges of the fingers in the following manner.''Gray's anatomy'' (1918), see infobox Opposite the metacarpophalangeal articulation each tendon is bound by fasciculi to the collateral ligaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Extensor Carpi Radialis Brevis
In human anatomy, extensor carpi radialis brevis is a muscle in the forearm that acts to extend and abduct the wrist. It is shorter and thicker than its namesake extensor carpi radialis longus which can be found above the proximal end of the extensor carpi radialis brevis. Origin and insertion It arises from the lateral epicondyle of the humerus, by the common extensor tendon; from the radial collateral ligament of the elbow-joint; from a strong aponeurosis which covers its surface; and from the intermuscular septa between it and the adjacent muscles.''Gray's Anatomy'' 1918, see infobox The fibres end approximately at the middle of the forearm in the form of a flat tendon, which is closely connected with that of the extensor carpi radialis longus, and accompanies it to the wrist; it passes beneath the abductor pollicis longus and extensor pollicis brevis, beneath the extensor retinaculum, and inserts into the lateral dorsal surface of the base of the third metacarpal bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pronator Quadratus
Pronator quadratus is a square-shaped muscle on the distal forearm that acts to pronate (turn so the palm faces downwards) the hand. Structure Its fibres run perpendicular to the direction of the arm, running from the most distal quarter of the anterior ulna to the distal quarter of the radius. It has two heads: the superficial head originates from the anterior distal aspect of the diaphysis (shaft) of the ulna and inserts into the anterior distal diaphysis of the radius, as well as its anterior metaphysis. The deep head has the same origin, but inserts proximal to the ulnar notch. It is the only muscle that attaches only to the ulna at one end and the radius at the other end. Arterial blood comes via the anterior interosseous artery. Innervation Pronator quadratus muscle is innervated by the anterior interosseous nerve, a branch of the median nerve. Function When pronator quadratus contracts, it pulls the lateral Lateral is a geometric term of location which may also r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Flexor Pollicis Longus
The flexor pollicis longus (; FPL, Latin ''flexor'', bender; ''pollicis'', of the thumb; ''longus'', long) is a muscle in the forearm and hand that flexes the thumb. It lies in the same plane as the flexor digitorum profundus. This muscle is unique to humans, being either rudimentary or absent in other primates. A meta-analysis indicated accessory flexor pollicis longus is present in around 48% of the population. Human anatomy Origin and insertion It arises from the grooved anterior (side of palm) surface of the body of the radius, extending from immediately below the radial tuberosity and oblique line to within a short distance of the pronator quadratus muscle.Gray 1918, ''Flexor Pollicis Longus'', paras 20, 25 An occasionally present accessory long head of the flexor pollicis longus muscle is called 'Gantzer's muscle'. It may cause compression of the anterior interosseous nerve. It arises also from the adjacent part of the interosseous membrane of the forearm, and genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Flexor Digitorum Profundus
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 Muscles of the hand#Extrinsic, extrinsic hand muscle because it acts on the hand while its muscle belly is located in the forearm. Together the Flexor pollicis longus muscle, flexor pollicis longus, Pronator quadratus muscle, 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 phalanges, 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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Flexor Digitorum Superficialis
Flexor digitorum superficialis (''flexor digitorum sublimis'') or flexor digitorum communis sublimis is an extrinsic flexor muscle of the fingers at the proximal interphalangeal joints. It is in the anterior compartment of the forearm. It is sometimes considered to be the deepest part of the superficial layer of this compartment, and sometimes considered to be a distinct, "intermediate layer" of this compartment. It is relatively common for the Flexor digitorum superficialis to be missing from the little finger, bilaterally and unilaterally, which can cause problems when diagnosing a little finger injury. Structure The muscle has two classically described heads – the humeroulnar and radial – and it is between these heads that the median nerve and ulnar artery pass. The ulnar collateral ligament of elbow joint gives its origin to part of this muscle. Four long tendons come off this muscle near the wrist and travel through the carpal tunnel formed by the flexor retinacu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 C6-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 brac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Palmaris Longus
The palmaris longus is a muscle visible as a small tendon located between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. Reviews report rates of absence in the general population ranging from 10–20%; however, the rate varies in different ethnic groups. Absence of the palmaris longus does not have an effect on grip strength. The lack of palmaris longus muscle does result in decreased pinch strength in fourth and fifth fingers. The absence of palmaris longus muscle is more prevalent in females than males. The palmaris longus muscle can be observed by touching the pads of the fourth finger and thumb and flexing the wrist. The tendon, if present, will be visible in the midline of the anterior wrist. Structure Palmaris longus is a slender, elongated, spindle shaped muscle, lying on the medial side of the flexor carpi radialis. It is widest in the middle, and narrowest at the proximal and distal attachments.''Gray's Anatomy'' (1918), see in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ulnar Nerve
The ulnar nerve is a nerve that runs near the ulna, one of the two long bones in the forearm. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is common. This nerve is directly connected to the little finger, and the adjacent half of the ring finger, innervating the palmar aspect of these fingers, including both front and back of the tips, perhaps as far back as the fingernail beds. This nerve can cause an electric shock-like sensation by striking the medial epicondyle of the humerus posteriorly, or inferiorly with the elbow flexed. The ulnar nerve is trapped between the bone and the overlying skin at this point. This is commonly referred to as bumping one's "funny bone". This name is thought to be a pun, based on the sound resemblance between the name of the bone of the upper arm, the humerus, and the word " humorous". Alternatively, according to the Oxfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
