brachial plexus

https://doi.org/10.1351/goldbook.11644
Bundle of nerve fibers that begins in the spine at the base of the neck, travels through the axilla (armpit region), and into the arm.
Note: Damage to these motor and sensory nerves affects muscle function and sensation in the arm and chest.
Source:
PAC, 2015, 87, 841. (IUPAC Glossary of terms used in neurotoxicology (IUPAC Recommendations 2015)) on page 853 [Terms] [Paper]