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Upper Trunk
The upper (superior) trunk is part of the brachial plexus. It is formed by joining of the ventral rami of the fifth (C5) and sixth (C6) cervical nerves. The upper trunk divides into an anterior and posterior division. The branches of the upper trunk from proximal to distal are: * subclavian nerve (C5-C6) *suprascapular nerve (C5-C6) *anterior division of upper trunk (C5-C6, forms part of lateral cord) *posterior division of upper trunk (C5-C6, forms part of posterior cord) The axillary, radial, musculocutaneous and 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 contr ...s all contain axons derived from the upper trunk. Additional images File:Slide1cord.JPG, Brachial plexus.Deep dissection. File:Slide1ecc.JPG, Brachial plexus.Deep dissection.Anterolateral view {{Authori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subclavian Nerve
The subclavian nerve, also known as the nerve to the subclavius, is small branch of the upper trunk of the brachial plexus. It contains axons from C5 and C6. The subclavian nerve innervates the subclavius muscle. Structure The subclavian nerve is a branch of the upper trunk of the brachial plexus. It contains axons derived from the ventral rami of the C5 and C6 cervical spinal nerves. Variation The subclavian nerve can variably give rise to a branch which innervates the diaphragm called the accessory phrenic nerve. The accessory phrenic nerve may rather branch from the C4 or C6 segments or ansa cervicalis. This nerve usually joins with the phrenic nerve before innervating the diaphragm, ventral to the subclavian vein. Function The subclavian nerve innervates the subclavius muscle The subclavius is a small triangular muscle, placed between the clavicle and the first rib. Along with the pectoralis major and pectoralis minor muscles, the subclavius muscle makes up the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprascapular Nerve
The suprascapular nerve is a nerve that branches from the upper trunk of the brachial plexus. It is responsible for the innervation of two of the muscles that originate from the scapula, namely the supraspinatus muscle, supraspinatus and infraspinatus muscles. Structure The suprascapular nerve arises from the upper trunk of the brachial plexus which is formed by the union of the Anterior ramus of spinal nerve, ventral rami of the fifth and sixth cervical nerves. After branching from the upper trunk, the nerve passes across the posterior triangle of the neck parallel to the inferior belly of the omohyoid muscle and deep to the trapezius muscle. It then runs along the Scapula#Borders, superior border of the scapula through the suprascapular canal, in which it enters via the suprascapular notch inferior to the superior transverse scapular ligament and enters the supraspinous fossa. It then passes beneath the supraspinatus, and curves around the lateral border of the spine of the scapul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachial Plexus
The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit, it supplies afferent and efferent nerve fibers the to chest, shoulder, arm, forearm, and hand. Structure The brachial plexus is divided into five ''roots'', three ''trunks'', six ''divisions'' (three anterior and three posterior), three ''cords'', and five ''branches''. There are five "terminal" branches and numerous other "pre-terminal" or "collateral" branches, such as the subscapular nerve, the thoracodorsal nerve, and the long thoracic nerve, that leave the plexus at various points along its length. A common structure used to identify part of the brachial plexus in cadaver dissections is the M or W shape made by the musculocutaneous nerve, lateral cord, median nerve, medial cord, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Ramus Of Spinal Nerve
The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami. Shortly after a spinal nerve exits the intervertebral foramen, it branches into the dorsal ramus, the ventral ramus, and the ramus communicans. Each of these three structures carries both sensory and motor information. Each spinal nerve carries both sensory and motor information, via efferent and afferent nerve fibers - ultimately via the motor cortex in the frontal lobe and to somatosensory cortex in the parietal lobe - but also through the phenomenon of reflex. Spinal nerves are referred to as "mixed nerves". In the thoracic region they remain distinct from each other and each innervates a narrow strip of muscle and skin along the sides, chest, ribs, and abdominal wall. These rami are called the intercostal nerves. In regions other than the thoracic, ventr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Cord
The lateral cord is the part of the brachial plexus formed by the anterior divisions of the upper (C5-C6) and middle trunks (C7). Its name comes from it being lateral to the axillary artery as it passes through the axilla. The other cords of the brachial plexus are the posterior cord and medial cord. The lateral cord gives rise to the following nerves from proximal to distal: *lateral pectoral nerve (C5-C7) *musculocutaneous nerve (C5-C7) *lateral head of median nerve (C5-C7) [other part of median nerve comes from medial cord The medial cord is the part of the brachial plexus formed by of the anterior division of the lower trunk (C8-T1). Its name comes from it being medial to the axillary artery as it passes through the axilla. The other cords of the brachial plexus ar ...] Additional images File:Slide10EEEE.JPG, Lateral cord File:Slide1cord.JPG, Brachial plexus.Deep dissection. Nerves of the upper limb {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cord
The posterior cord is a part of the brachial plexus The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th .... It consists of contributions from all of the roots of the brachial plexus. The posterior cord gives rise to the following nerves: Additional images File:PLEXUS BRACHIALIS.jpg, Brachial plexus File:Slide12OOO.JPG, Posterior cord File:Slide1SSS.JPG, Posterior cord File:Slide1cord.JPG, Brachial plexus.Deep dissection. File:Slide1ecc.JPG, Brachial plexus.Deep dissection.Anterolateral view References MBBS resources http://mbbsbasic.googlepages.com/ External links * - "Axilla, dissection, anterior view" Nerves of the upper limb {{neuroscience-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axillary Nerve
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the deltoid and teres minor. Structure The nerve lies at first behind the axillary artery, and in front of the subscapularis, and passes downward to the lower border of that muscle. It then winds from anterior to posterior around the neck of the humerus, in company with the posterior humeral circumflex artery, through the quadrangular space (bounded above by the teres minor, below by the teres major, medially by the long head of the triceps brachii, and laterally by the surgical neck of the humerus), and divides into an anterior, a posterior, and a collateral branch to the long head of the triceps brachii branch. * The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Nerve
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin. It originates from the brachial plexus, carrying fibers from the ventral roots of spinal nerves C5, C6, C7, C8 & T1. The radial nerve and its branches provide motor innervation to the dorsal arm muscles (the triceps brachii and the anconeus) and the extrinsic extensors of the wrists and hands; it also provides cutaneous sensory innervation to most of the back of the hand, except for the back of the little finger and adjacent half of the ring finger (which are innervated by the ulnar nerve). The radial nerve divides into a deep branch, which becomes the posterior interosseous nerve, and a superficial branch, which goes on to innervate the dorsum (back) of the hand. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musculocutaneous
The musculocutaneous nerve arises from the lateral cord of the brachial plexus, opposite the lower border of the pectoralis major, its fibers being derived from C5, C6 and C7. Structure The musculocutaneous nerve arises from the lateral cord of the brachial plexus, courses through the anterior part of the arm, and terminates at 2 cm above elbow as the lateral cutaneous nerve of the forearm. Musculocutaneous nerve arises from the lateral cord of the brachial plexus with root value of C5 to C7 of the spinal cord. It follows the course of the third part of the axillary artery (part of the axillary artery distal to the pectoralis minor) laterally and enters the frontal aspect of the arm where it penetrates the coracobrachialis muscle. It then passes downwards and laterally between the biceps brachii (above) and the brachialis muscles (below), to the lateral side of the arm; at 2 cm above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii an ... [...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] |
