Long Thoracic Nerve
| |
| Long Thoracic Nerve | |
|---|---|
| Nerve Type | Motor nerve |
| Origin | ventral rami of C5, C6, and C7 |
| Course | between the middle and posterior scalene muscles, then along the lateral thoracic wall |
| Motor innervation | Serratus Anterior |
| Conditions | Scapular Winging |
The long thoracic nerve (LTN) is a peripheral nerve that primarily provides motor innervation to the serratus anterior muscle.
Nerve Type
The LTN is a motor nerve.
Origin
It originates from the ventral rami of the C5, C6, and C7 cervical nerve roots.
Course
The LTN travels through the cervicothoracic region, passing posterior to the brachial plexus and the axillary vessels. It typically courses between the middle and posterior scalene muscles, then descends along the lateral thoracic wall to innervate the serratus anterior muscle.
Branches
The LTN has several branches that innervate different parts of the serratus anterior muscle. The upper portion of the muscle is primarily innervated by branches from C5, while the middle and lower portions receive innervation from C6 and C7.
Motor Innervation
The LTN innervates the serratus anterior muscle, which is responsible for protracting the scapula and holding it against the thoracic wall, facilitating shoulder elevation and preventing scapular winging.
Associated Medical Conditions
Injury to the LTN can lead to serratus anterior muscle paralysis, resulting in scapular winging, shoulder pain, and limited shoulder elevation. Common causes of LTN injury include trauma, repetitive strain, surgical complications, and neuralgic amyotrophy.
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