France and the United Kingdom agreed to support Poland and in August of 1939, German troops began to gather on the Polish border. By September 1st, Germany launched an invasion of Poland.
The brachial plexus is a network of nerves that originate in the neck region and branch off to form most of the other nerves that control movement and sensation in the upper limbs, including the shoulder, arm, forearm, and hand.
The Cervical Plexus. The cervical plexus is a network of nerve fibres that supplies innervation to some of the structures in the neck and trunk. It is located in the posterior triangle of the neck, halfway up the sternocleidomastoid muscle, and within the prevertebral layer of cervical fascia. The plexus is formed by the anterior rami (divisions) of cervical spinal nerves C1-C4.