Plexuksen

Plexus, in anatomy, is a network or braided arrangement of nerves, blood vessels, or lymphatics that join and diverge to supply a region. The term comes from Latin plexus meaning braided. Nerve plexuses form when ventral rami of spinal nerves merge and rejoin to distribute fibers to limbs and trunk.

The major nerve plexuses are: the cervical plexus (C1–C4), which supplies the neck and gives rise to the phrenic nerve (C3–C5); the brachial plexus (C5–T1), which provides innervation to the upper limb with major branches such as the axillary, radial, median, ulnar, and musculocutaneous nerves; the lumbar plexus (L1–L4) and sacral plexus (L4–S4), which together supply the lower limb and pelvis. Plexuses provide redundancy so damage to a single nerve can be mitigated by others, though deficits may still occur.

Autonomic or vascular plexuses organize nerve fibers around major vessels or organs. Notable examples include the solar plexus (celiac plexus) around the origin of the celiac trunk, the cardiac plexus near the heart, and the pulmonary plexus around the bronchi. These networks coordinate autonomic control of thoracic and abdominal organs.

Clinical relevance: plexuses can be injured by trauma, compression, or inflammation, producing plexopathy. Diagnosis relies on imaging and nerve studies; treatment includes rehabilitation and, in some cases, nerve blocks or surgical decompression. The term plexus is also used for network-like arrangements of vessels or lymphatics in various regions.