Posterior interosseous nerve: Difference between revisions

Latest revision as of 11:37, 15 February 2025

Anatomy and function of the posterior interosseous nerve

Posterior Interosseous Nerve[edit]

The posterior interosseous nerve is a branch of the radial nerve that supplies the extensor muscles of the forearm. It is primarily responsible for the motor innervation of these muscles, which are involved in the extension of the wrist and fingers.

Diagram of the posterior interosseous nerve and its branches.

Anatomy[edit]

The posterior interosseous nerve originates from the radial nerve, which is a major nerve of the upper limb. The radial nerve itself arises from the brachial plexus, specifically from the posterior cord. After the radial nerve passes through the radial groove of the humerus, it divides into a superficial branch and a deep branch. The deep branch continues as the posterior interosseous nerve.

The nerve enters the forearm by passing through the supinator muscle, a muscle that assists in the supination of the forearm. As it emerges from the supinator, it travels along the posterior aspect of the interosseous membrane, which is a fibrous sheet connecting the radius and ulna bones of the forearm.

Function[edit]

The primary function of the posterior interosseous nerve is to provide motor innervation to the extensor muscles of the forearm. These muscles include:

These muscles are responsible for extending the wrist and fingers, as well as abducting the thumb.

Clinical Significance[edit]

Injury to the posterior interosseous nerve can result in a condition known as posterior interosseous nerve syndrome. This condition is characterized by weakness or paralysis of the extensor muscles of the forearm, leading to difficulty in extending the wrist and fingers. It can be caused by trauma, compression, or entrapment of the nerve, often at the level of the supinator muscle.

Symptoms of posterior interosseous nerve syndrome include wrist drop, where the patient is unable to extend the wrist, and weakness in finger extension. Diagnosis is typically made through clinical examination and may be confirmed with electromyography (EMG) studies.

Related pages[edit]

@@ Line 1: / Line 1: @@
-'''Posterior interosseous nerve''' ('''PIN''') is a nerve in the human body that is a branch of the [[radial nerve]]. It is responsible for the extension of the fingers and the wrist, as well as the supination of the forearm.
+{{Short description|Anatomy and function of the posterior interosseous nerve}}
-==Etymology==
+==Posterior Interosseous Nerve==
-The term "interosseous" comes from the Latin words "inter", meaning "between", and "osseus", meaning "bony". This refers to the nerve's location between the two bones of the forearm, the [[radius]] and the [[ulna]].
+The '''posterior interosseous nerve''' is a branch of the [[radial nerve]] that supplies the [[extensor muscles]] of the forearm. It is primarily responsible for the motor innervation of these muscles, which are involved in the extension of the wrist and fingers.
-==Anatomy==
+[[File:Gray420.png|thumb|right|300px|Diagram of the posterior interosseous nerve and its branches.]]
-The posterior interosseous nerve originates from the radial nerve, which itself is a branch of the [[brachial plexus]]. The PIN travels down the forearm, passing through the [[supinator muscle]] before dividing into several smaller branches. These branches innervate the extensor muscles of the forearm, including the [[extensor carpi ulnaris]], the [[extensor digitorum]], and the [[extensor pollicis longus]].
-==Clinical significance==
+===Anatomy===
-Damage to the posterior interosseous nerve can result in a condition known as [[Posterior interosseous syndrome]] (PIS). This condition is characterized by the inability to extend the fingers and the wrist, as well as weakness in the supination of the forearm. PIS can be caused by a variety of factors, including direct trauma, compression from a tumor or cyst, or repetitive strain injury.
+The posterior interosseous nerve originates from the radial nerve, which is a major nerve of the upper limb. The radial nerve itself arises from the [[brachial plexus]], specifically from the posterior cord. After the radial nerve passes through the [[radial groove]] of the [[humerus]], it divides into a superficial branch and a deep branch. The deep branch continues as the posterior interosseous nerve.
-==Related terms==
+The nerve enters the forearm by passing through the [[supinator muscle]], a muscle that assists in the supination of the forearm. As it emerges from the supinator, it travels along the posterior aspect of the interosseous membrane, which is a fibrous sheet connecting the [[radius]] and [[ulna]] bones of the forearm.
+===Function===
+The primary function of the posterior interosseous nerve is to provide motor innervation to the extensor muscles of the forearm. These muscles include:
+* [[Extensor carpi radialis brevis]]
+* [[Extensor digitorum]]
+* [[Extensor digiti minimi]]
+* [[Extensor carpi ulnaris]]
+* [[Abductor pollicis longus]]
+* [[Extensor pollicis brevis]]
+* [[Extensor pollicis longus]]
+* [[Extensor indicis]]
+These muscles are responsible for extending the wrist and fingers, as well as abducting the thumb.
+===Clinical Significance===
+Injury to the posterior interosseous nerve can result in a condition known as [[posterior interosseous nerve syndrome]]. This condition is characterized by weakness or paralysis of the extensor muscles of the forearm, leading to difficulty in extending the wrist and fingers. It can be caused by trauma, compression, or entrapment of the nerve, often at the level of the supinator muscle.
+Symptoms of posterior interosseous nerve syndrome include wrist drop, where the patient is unable to extend the wrist, and weakness in finger extension. Diagnosis is typically made through clinical examination and may be confirmed with [[electromyography]] (EMG) studies.
+==Related pages==
 * [[Radial nerve]]
 * [[Brachial plexus]]
-* [[Supinator muscle]]
+* [[Extensor muscles of the forearm]]
-* [[Extensor carpi ulnaris]]
+* [[Wrist drop]]
-* [[Extensor digitorum]]
-* [[Extensor pollicis longus]]
-* [[Posterior interosseous syndrome]]
 [[Category:Peripheral nervous system]]
-[[Category:Anatomy]]
+[[Category:Upper limb anatomy]]
-[[Category:Medical terminology]]
-{{stub}}