Corpus: Intercostobrachial nerve
from Latin: inter - between; costa - rib; brachium - arm
1. Definition
The intercostobrachial nerve is the lateral, sensory cutaneous branch of the 2nd intercostal nerve, and may also include fibres from the 3rd intercostal nerve.
2. Anatomy
The intercostobrachial nerve pierces the external intercostal and anterior serratus muscles, then travels through the axilla to the medial side of the upper arm. It communicates with the medial brachial cutaneous nerve, sometimes forming a small plexus in the axilla. It passes through the fascia and branches into the subcutaneous tissue of the medial and dorsal proximal half of the upper arm, where it connects with the dorsal cutaneous branch of the radial nerve.
3. Function
The intercostobrachial nerve provides sensory innervation to the axilla and the dorsal and medial skin areas of the proximal upper arm.
4. Clinic
This nerve can be damaged during axillary lymph node dissection. It also plays a role in referred pain to the left arm during myocardial infarction, as part of the cardiac pain pathway.