| Nerve: Radial nerve | |
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| The suprascapular, axillary, and radial nerves. The suprascapular nerve arises from the trunk formed by the union of the fifth and sixth Cervical nerves. The axillary nerve is a Nerve of the human body that comes off the Posterior cord of the Brachial plexus at the level of the Axilla (armpit | |
| Latin | nervus radialis |
| Gray's | subject #210 943 |
| Innervates | posterior compartment of the arm, posterior compartment of the forearm |
| From | posterior cord |
| To | posterior interosseous nerve |
| MeSH | Radial+Nerve |
| Dorlands / Elsevier |
n_05/12566581 |
The radial nerve is a nerve in the human body that supplies the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This is a list of the subjects in Gray's Anatomy: IX Neurology The posterior compartment of the arm is an Anatomic compartment which contains muscles which are all supplied by the Radial nerve. The posterior compartment of the forearm (or extensor compartment) contains the following muscles See also Compartment syndrome The posterior cord is a division of the Brachial plexus. It consists of contributions from all of the roots of the brachial plexus The posterior interosseous nerve (or dorsal interosseous nerve) is a Nerve in the foream Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. The posterior compartment of the arm is an Anatomic compartment which contains muscles which are all supplied by the Radial nerve.
It originates from the posterior cord of the brachial plexus with roots from C5, C6, C7, C8 & T1. The brachial Plexus is an arrangement of nerve fibers running from the spine formed by the Ventral rami of the lower cervical and upper thoracic nerve roots specifically
The radial nerve and its branches supply the dorsal muscles, such as triceps brachii, the extrinsic extensors of the wrist and hands, and the cutaneous nerve supply to most of the back of the hand. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. (The ulnar nerve cutaneously innervates the back of the little finger. In Human anatomy, the ulnar nerve is a nerve which runs near the Ulna bone )
The radial nerve divides into a deep branch, (which becomes the posterior interosseous nerve), and continues as the superficial branch which goes on to innervate the dorsum (back) of the hand. The posterior interosseous nerve (or dorsal interosseous nerve) is a Nerve in the foream
Contents |
Course
The radial nerve originates as a terminal branch of the posterior cord of the brachial plexus. The posterior cord is a division of the Brachial plexus. It consists of contributions from all of the roots of the brachial plexus The brachial Plexus is an arrangement of nerve fibers running from the spine formed by the Ventral rami of the lower cervical and upper thoracic nerve roots specifically It goes through the arm, first in the posterior compartment of the arm, and later in the anterior compartment of the arm, and continues in the forearm. The posterior compartment of the arm is an Anatomic compartment which contains muscles which are all supplied by the Radial nerve. The anterior compartment of the arm is known as the "flexor compartment" as Flexion is its main action
In arm
From the brachial plexus, it travels posteriorly through what often called the triangular interval (US) or lower triangular space (UK). The triangular interval (also known as the lateral triangular space and lower triangular space) is a space found in the Axilla.
The radial nerve enters the arm behind the axillary artery/brachial artery, and it then travels posteriorly on the medial side of the arm. In Human anatomy, the axillary artery is a large Blood vessel that conveys oxygenated Blood to the lateral aspect of the Thorax, the Axilla The brachial artery is the major Blood vessel of the upper arm
After giving off branches to the long and lateral heads of the triceps brachii, it enters a groove on the humerus, the radial sulcus. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. The radial sulcus ( also known as the musculospiral groove, radial groove, or spiral groove) is a broad but shallow oblique depression for the Radial
Along with the deep brachial artery, the radial nerve winds around in the groove (between the medial and lateral heads of the triceps) towards the forearm, running laterally on the posterior aspect of the humerus. The arteria profunda brachii (also known as deep artery of the arm) is a large vessel which arises from the Medial and back part of the Brachial, just below
While in the groove, it gives off a branch to the medial head of the triceps brachii. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb.
The radial nerve emerges from the groove on the lateral aspect of the humerus.
At this point, it pierces the lateral intermuscular septum and enters the anterior compartment of the arm. The anterior compartment of the arm is known as the "flexor compartment" as Flexion is its main action
It continues its journey inferiorly between the brachialis and brachioradialis muscles. The brachialis ( brachialis anticus) is a Muscle in the upper Arm that flexes the elbow joint. Brachioradialis is a Muscle of the Forearm that acts to flex the forearm at the Elbow.
When the radial nerve reaches the distal part of the humerus, it passes in front of the lateral epicondyle and continues in the forearm. The lower extremity of the Humerus is flattened from before backward and curved slightly forward it ends below in a broad articular surface which is divided into two parts
In forearm
In the forearm, it branches into a superficial branch (primarily sensory) and a deep branch (primarily motor).
- The superficial branch of the radial nerve descends in the forearm under the brachioradialis. The superficial branch of the Radial nerve passes along the front of the radial side of the Forearm to the commencement of its lower third Brachioradialis is a Muscle of the Forearm that acts to flex the forearm at the Elbow. It eventually pierces the deep fascia near the back of the wrist.
- The deep branch of the radial nerve pierces the supinator muscle, after which it is known as the posterior interosseous nerve. The deep branch of the Radial nerve winds to the back of the Forearm around the lateral side of the radius between the two planes of fibers of the Supinator The supinator is a broad muscle curved around the upper third of the radius. The posterior interosseous nerve (or dorsal interosseous nerve) is a Nerve in the foream
Branches/Innervations
The following are branches/innervations of the radial nerve (including the superficial branch of the radial nerve and the deep branch of the radial nerve/posterior interosseous nerve).
Cutaneous
Cutaneous innervation is provided by the following nerves:
- Posterior cutaneous nerve of arm (originates in axilla)
- Inferior lateral cutaneous nerve of arm (originates in arm)
- Posterior cutaneous nerve of forearm (originates in arm)
The superficial branch of the radial nerve provides sensory innervation to much of the back of the hand, including the web of skin between the thumb and index finger. Cutaneous innervation refers to the area of the Skin which is supplied by a specific Nerve, that is by a Cutaneous nerve. The posterior cutaneous nerve of arm ( internal cutaneous branch of musculospiral, posterior brachial cutaneous nerve) is a branch of the radial nerve that provides The inferior lateral cutaneous nerve of arm (also called the inferior lateral brachial cutaneous nerve) is a branch of the Radial nerve that provides sensory innervation The dorsal antibrachial cutaneous nerve ( external cutaneous branch of musculospiral, posterior antebrachial cutaneous nerve, posterior cutaneous nerve of forearm The superficial branch of the Radial nerve passes along the front of the radial side of the Forearm to the commencement of its lower third
Motor
Muscular branches of the radial nerve:
Deep branch of the radial nerve:
Posterior interosseous nerve (a continuation of the deep branch after the supinator):
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis
The radial nerve (and its deep branch) provides motor innervation to the muscles in the posterior compartment of the arm and forearm, which are mostly extensors. The muscular branches of the Radial nerve supply the Triceps brachii, Anconæus, Brachioradialis, Extensor carpi radialis longus, The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. The anconeus muscle is a small Muscle on the posterior aspect of the elbow joint Brachioradialis is a Muscle of the Forearm that acts to flex the forearm at the Elbow. Extensor carpi radialis longus is one of the five main Muscles that control movement at the Wrist. The deep branch of the Radial nerve winds to the back of the Forearm around the lateral side of the radius between the two planes of fibers of the Supinator The Extensor carpi radialis brevis is shorter and thicker than the longus, beneath which it is placed The supinator is a broad muscle curved around the upper third of the radius. The posterior interosseous nerve (or dorsal interosseous nerve) is a Nerve in the foream The Extensor digitorum ( Extensor digitorum communis) arises from the lateral epicondyle of the Humerus, by the common tendon from the intermuscular septa The extensor minimi digiti ( extensor digiti quinti proprius) is a slender muscle of the Forearm, placed on the ulnar side of the Extensor digitorum communis Extensor carpi ulnaris is a Muscle located in the human Forearm that acts to extend and adduct the Wrist. The Abductor pollicis longus lies immediately below the Supinator and is sometimes united with it The Extensor pollicis brevis lies on the medial side of and is closely connected with the Abductor pollicis longus. The Extensor pollicis longus is much larger than the Extensor pollicis brevis muscle the origin of which it partly covers The extensor indicis proprius (Extensor indicis is a narrow elongated muscle placed medial to and parallel with the Extensor pollicis longus. The posterior compartment of the arm is an Anatomic compartment which contains muscles which are all supplied by the Radial nerve. The posterior compartment of the forearm (or extensor compartment) contains the following muscles See also Compartment syndrome Extension is a movement of a joint that results in increased angle between two bones or body surfaces at a joint
Additional images
 Brachial plexus |
 Cross-section through the middle of upper arm. |
 Cross-section through the middle of the forearm. |
 The brachial artery. |
 Suprascapular and axillary nerves of right side, seen from behind. |
 Cutaneous nerves of right upper extremity. |
 Diagram of segmental distribution of the cutaneous nerves of the right upper extremity. Posterior view. |
 Superficial palmar nerves. |
 Nerves of the left upper extremity. |
 Deep palmar nerves. |
 Front of right upper extremity, showing surface markings for bones, arteries, and nerves. |
 Back of right upper extremity, showing surface markings for bones and nerves. |
See also
- Muscular branches of the radial nerve
- Cutaneous branches of the radial nerve
- Superficial branch of the radial nerve
- Deep branch of the radial nerve
External links
- Duke Orthopedics radial_nerve
- Atlas of anatomy at UMich hand_plexus - "Axilla, dissection, anterior view"
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