Introduction The lumbar plexus is a neural network formed by the anterior rami of spinal nerves L1 through L4 and the anterior ramus of spinal nerve T12. It is situated on the posterior abdominal wall, anterior to the transverse processes of the lumbar vertebrae, and inside the posterior section of the psoas major muscle. The…
Introduction The brachial plexus is a network of nerves that originates from the spinal cord in the neck (C5 to T1 nerve roots) and extends through the shoulder to control muscle movements and sensation in the shoulder, arm, and hand. It is divided into five sections: roots, trunks, divisions, cords, and branches. Damage to the…
Introduction The dorsal scapular nerve originates from the root of spinal nerve C5, which is one of the brachial plexus’s lateral branches. On rare occasions, it could originate from the brachial plexus’ superior trunk. The dorsal scapular nerve is a motor neuron that innervates the levator scapulae, rhomboid major, and rhomboid minor muscles. These muscles…
Introduction The medial antebrachial cutaneous nerve is a sensory nerve originating from the medial cord of the brachial plexus, primarily carrying fibers from the C8 and T1 nerve roots. It supplies sensation to the skin of the medial (inner) side of the forearm. The nerve descends along the arm, often near the basilic vein, and…
Introduction The medial pectoral nerve arises from the medial cord of the brachial plexus (C8-T1). It primarily innervates the pectoralis major (sternocostal head) and pectoralis minor muscles. Unlike the lateral pectoral nerve, it pierces the pectoralis minor before reaching the pectoralis major. This nerve plays a role in shoulder adduction, internal rotation, and scapular stabilization….
Introduction The Anterior Interosseous Nerve (AIN) is a branch of the median nerve that arises in the forearm. It supplies the flexor pollicis longus (FPL), the lateral half of the flexor digitorum profundus (FDP) (to the index and middle fingers), and the pronator quadratus (PQ). It is purely a motor nerve, with no sensory function….
Introduction The long thoracic nerve arises from the C5-C7 nerve roots and innervates the serratus anterior muscle. It plays a crucial role in scapular stability, preventing winging of the shoulder blade. Injury to this nerve can result in scapular winging, weakness in shoulder protraction, and difficulty in overhead movements. The serratus anterior muscle, one of…
The coccygeal nerve is the 31st and final spinal nerve, arising from the coccygeal region of the spinal cord. It primarily contributes to the coccygeal plexus, which provides sensory innervation to the skin over the coccyx and motor fibers to parts of the pelvic floor muscles. It plays a minor role in overall nerve function…
Introduction The inferior gluteal nerve is also a motor branch of the sacral plexus, coming from the posterior divisions of the L5, S1, and S2 anterior roots. It flows inferiorly and exits the pelvic cavity via the larger sciatic foramen while going inferiorly to the piriformis muscle. The gluteus maximus muscle receives motor innervation from…
Introduction The superior gluteal nerve, a motor branch of the sacral plexus, originates from the posterior divisions of the L4, L5, and S1 anterior roots. The superior gluteal nerve and vessels travel through the greater sciatic foramen before passing superiorly to the piriformis muscle. From there, the nerve splits into its superior and inferior branches,…
