Lateral Cutaneous Branch of Third Intercostal Nerve (Left)
Ramus cutaneus lateralis nervi intercostalis tertii
Read moreQuick Facts
Origin: Third intercostal nerve.
Course: Pierces the chest wall anterior to serratus anterior muscle.
Branches: Anterior and posterior branches.
Supply: Skin of overlying third intercostal space.
Related parts of the anatomy
Origin
The lateral cutaneous branch of anterior ramus of third thoracic nerve (or third intercostal nerve) arises from the anterior ramus of the third thoracic nerve roughly along the mid-axillary line.
Course
The lateral cutaneous branch may travel for a short distance with its parent nerve (the anterior ramus) within the intercostal space. It then pierces the thoracic wall through the internal and external intercostal muscles, emerging just anterior to the serratus anterior muscle.
Branches
The lateral cutaneous branch further subdivides into anterior and posterior branches. The anterior branches extend towards the pectoralis major, while the posterior branches extend backwards towards the latissimus dorsi muscle.
Supplied Structures & Function
The lateral cutaneous branch of the third intercostal nerve (or anterior ramus of third thoracic nerve) conveys sensory innervation from the skin overlying the third intercostal space. See our dermatome map for cutaneous innervation. In some instances, a second intercostobrachial nerve arises from the lateral cutaneous branch, which also sends nerve filaments to the axilla and medial arm.