Formation: Ventral rami of C6, C7, C8, T1, and T2 (Post-fixed arrangement).

Key Features:
- Located deep in axillary space
- Forms broad 'plexus sheet' around axillary artery
- C6-C7: Cranial roots (shoulder/stabilization)
- C8-T2: Caudal roots (flexors/foot)

Clinical Significance:
T2 inclusion serves massive pectoral muscles and cutaneous trunci (fly swatting reflex).

NEURO-ARCHITECTURAL MASTERPIECE

The Brachial Plexus (Plexus brachialis) is the somatic nerve network serving as the command center for the thoracic limb. In the Ox, it exhibits a 'post-fixed' arrangement compared to the 'pre-fixed' plexus of canines, reliably incorporating T2 to serve the massive pectoral girdle required for supporting ~60% of body weight.

SEGMENTAL FORMATION:

1. C6 (Cranial Driver): Primary contributor to shoulder stabilization (Suprascapular, Subscapular nerves). Sets tone for shoulder advancement.

2. C7 (Keystone Root): The central pillar providing massive contribution to the Radial nerve. Without C7, extensor tone is fundamentally compromised.

3. C8 (Transitional Bridge): Connects extensor functions of Radial with flexor functions of Median/Ulnar nerves.

4. T1 (Thoracic Power): Heavy investment supplying intrinsic foot muscles and powerful flexors of carpus/digits.

5. T2 (Ruminant Signature): The distinguishing feature contributing to caudal pectoral nerves and lateral thoracic wall innervation. Serves the panniculus reflex and massive brisket musculature.

SCALENE EMERGENCE: Unlike humans, ventral rami of C6, C7, C8 emerge through muscular separations of Scalenus dorsalis and ventralis, utilizing them as protective grommets. The plexus acts as a sorting house where fibers intermingle—a design safeguard ensuring damage to a single root (e.g., C7) results in paresis rather than total paralysis.

ANSA AXILLARIS: Musculocutaneous and Median nerves form a loop around the axillary artery, anchoring the neurovascular bundle to prevent kinking during extreme limb excursions.