Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland.
Department of Anatomical Sciences, St. George's University, Grenada, West Indies.
Folia Morphol (Warsz). 2023;82(1):225-230. doi: 10.5603/FM.a2021.0122. Epub 2021 Nov 16.
The biceps brachii is located in the anterior compartment of the arm, which can show numerous morphological variations. During anatomical dissection, an interesting additional muscle was found: the third head of the biceps brachii originated from the short head of the same muscle. The 97.77 mm long muscle belly was directed medially over the arm and then passed into the common tendon (15.97 mm), which thereafter split into aponeurosis and tendon. The 26.33 mm aponeurosis passed and joined the fascia of the forearm. The tendon of the third head of the biceps brachii then gave rise to the ulnar head of the pronator teres muscle. Such an accessory structure could cause neurovascular compression involving the brachial artery and median nerve. Knowledge of the morphological variability of this region is essential not only for anatomists but also for clinicians.
肱二头肌位于手臂的前腔室，可呈现出众多形态变异。在解剖过程中，发现了一个有趣的附加肌肉：肱二头肌的第三个头起源于同一肌肉的短头。这块长 97.77 毫米的肌腹向臂内侧走行，然后进入共同肌腱（15.97 毫米），此后肌腱分为腱膜和肌腱。26.33 毫米的腱膜穿过并与前臂筋膜相连。肱二头肌第三个头的肌腱然后发出旋前圆肌的尺骨头。这种附加结构可能导致涉及肱动脉和正中神经的神经血管压迫。不仅对解剖学家，而且对临床医生来说，了解该区域的形态变异性至关重要。
