Master of Technical Anatomy and Histology, Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Folia Morphol (Warsz). 2023;82(1):79-87. doi: 10.5603/FM.a2021.0139. Epub 2022 Jan 17.
The aim of the present work was to provide evidence about the anatomical variations as regard the origin, distribution, and branching pattern of the musculocutaneous nerve (MCN).
Brachial plexus was dissected in 40 upper limbs of 20 male adult cadavers. The pattern of the MCN was photographed by a digital camera.
The location and length of the nerve branches between left and right arms were recorded and statistically analysed. In 90% of specimens the MCN originates from the lateral cord of the brachial plexus, in 5% it arose from the median nerve (MN), while in the remaining 5% specimen, it was absent. The MCN pierced the coracobrachialis muscle in 90% of specimens, and in the remaining 10% did not pierce it. The motor branches to biceps brachii muscle were categorised into: type 1 (90%): one branch that divides to supply the two heads of biceps; type 2 (5%): double branches, innervating each head of biceps separately. The motor branches to brachialis muscle were categorised into: type 1 (82.9%): one branch; type 2 (14.2%): double branches and type 3 (2.9%): three branches that innervating brachialis muscle. Communications between the MCN and the MN were observed in 35% of specimens.
The knowledge of the common and uncommon MCN variations is important especially to the surgeons for carrying out surgical procedures in axilla and arm.
本研究旨在提供关于肌皮神经（MCN）起源、分布和分支模式的解剖学变异的证据。
在 20 具成年男性尸体的 40 个上肢中解剖臂丛。使用数码相机拍摄 MCN 的模式图。
记录并统计分析左右手臂神经分支的位置和长度。在 90%的标本中，MCN 起源于臂丛的外侧束，在 5%的标本中起源于正中神经（MN），而在其余 5%的标本中缺失。MCN 在 90%的标本中穿过喙肱肌，在其余 10%的标本中不穿过。肱二头肌的运动支分为：1 型（90%）：一支分支供应肱二头肌的两个头；2 型（5%）：双支，分别支配肱二头肌的每个头。肱肌的运动支分为：1 型（82.9%）：一支；2 型（14.2%）：两支和 3 型（2.9%）：三支，支配肱肌。在 35%的标本中观察到 MCN 与 MN 之间的通讯。
了解常见和不常见的 MCN 变异对于在腋窝和手臂进行手术的外科医生非常重要。
