Musculus serratus anterior

The serratus anterior is a fan-shaped muscle located between the lateral thorax wall and the scapula. It is divided into superior, intermediate, and inferior parts, originating from the first to ninth ribs. The muscle is innervated by the thoracic longus nerve and functions to displace the shoulder blade and elevate the ribs, aiding in respiration. The inferior part supports arm elevation above 90 degrees.

What is the role of the thoracic longus nerve in relation to the serratus anterior muscle?

How does the serratus anterior muscle contribute to shoulder movement?