Combination of six variations in a single arm

Area of Science:

• Anatomy
• Human Morphology
• Clinical Anatomy

Background:

• Neuromuscular variations in the upper limb are common due to complex developmental processes.
• Understanding these variations is critical for surgical and diagnostic procedures.

Purpose of the Study:

• To document a rare case of multiple neuromuscular variations occurring simultaneously in one upper limb.
• To highlight the anatomical significance of combined variations for medical professionals.

Main Methods:

• Routine dissection of a cadaver's left upper limb following established anatomical protocols.
• Photographic documentation of observed neuromuscular variations.

Main Results:

• An accessory head of the biceps brachii originating from the pectoralis major tendon.
• Identification of a pectoralis quartus muscle band.
• A double-headed coracobrachialis muscle.
• The musculocutaneous nerve bypassed the coracobrachialis, running beneath its bellies.
• The lateral cord of the brachial plexus divided lower than usual, between the coracobrachialis bellies.

Conclusions:

• The simultaneous occurrence of six distinct neuromuscular variations in a single upper limb is highly uncommon.
• This case underscores the importance of detailed anatomical knowledge for surgical interventions and understanding anatomical diversity.