Intercostobrachial nerve

It provides sensory innervation to the skin of the axilla, and a variable region of the medial side of the upper arm.It pierces the intercostalis externus muscle and the serratus anterior muscle, crosses the axilla to the medial side of the arm, and joins with a filament from the medial brachial cutaneous nerve.It then pierces the fascia, and supplies the skin of the upper half of the medial and posterior part of the arm, communicating with the posterior brachial cutaneous branch of the radial nerve.An additional intercostobrachial nerve is frequently given off from the lateral cutaneous branch of the third intercostal nerves; it supplies filaments to the axilla and medial side of the arm.This article incorporates text in the public domain from page 946 of the 20th edition of Gray's Anatomy (1918)
Intercostal nervesAnatomical terms of neuroanatomysecond intercostal nervelong thoracic nerveintercostalis externus muscleserratus anterior muscleaxillamedial brachial cutaneous nerveposterior brachial cutaneous branchradial nervelateral cutaneous branchthird intercostal nervesCutaneous innervation of the upper limbspublic domainGray's AnatomySpinal nervesCervicalanteriorCervical plexusBrachial plexusposteriorPosterior branches of cervical nervesSuboccipital – C1Greater occipital – C2Third occipital – C3ThoracicIntercostalThoraco-abdominal nerves – T7–T11Subcostal – T12Posterior branches of thoracic nervesLumbarLumbar plexusLumbosacral trunkPosterior branches of the lumbar nervesSuperior cluneal L1–L3SacralSacral plexusPosterior branches of sacral nervesMedial cluneal nervesCoccygealCoccygeal plexusPosterior branch of coccygeal nerve