Introduction The central nervous system (CNS) is a division of the nervous system that analyses and integrates different intrapersonal and extrapersonal information and produces a coordinated reaction to these stimuli. The brain and spinal cord are the two continuous central nervous system (CNS) organs. They are contained in two bony structures, the skull, and the…
Introduction The intercostal nerves are a group of 11 pairs of nerves that originate from the thoracic spinal cord (T1 to T11). They run between the ribs, supplying the muscles of the chest wall and providing sensory information from the skin and pleura. The 12th pair, called the subcostal nerve, runs below the last rib….
Introduction The cervical plexus is a collection of cervical nerves created by the anterior (ventral) rami of spinal nerves C1-C4 (sometimes known as the first through fourth cervical nerves). The cervical plexus’ roots (limbs) are shown here. The 5th cervical nerve (the anterior ramus of spinal nerve C5) may also be regarded as a member…
Introduction The sacral plexus is a neural network made up of the lumbosacral trunk (L4, L5) and the sacral spinal nerves (S1–S4). The sacral plexus is situated on the posterior pelvic wall, behind the internal iliac arteries and ureter, and ahead of the piriformis muscle. The plexus has multiple branches, including anterior, posterior, and one…
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….
