plexus

Examples of plexus in the following topics:

• Sacral and Coccygeal Plexuses

  • The sacral plexus is the plexus of the three sacral spinal nerves (S2–S4) that arise from the lower back just above the sacrum.
  • The sacral plexus is a nerve plexus that provides motor and sensory nerves for the posterior thigh, most of the lower leg, the entire foot, and part of the pelvis.
  • Often, the sacral plexus and the lumbar plexus are considered to be one large nerve plexus, the lumbosacral plexus.
  • The coccygeal plexus originates from the S4, S5, and Co1 spinal nerves.
  • It is interconnected with the lower part of the sacral plexus.

• Plexuses

  • The plexus extends toward the armpit (axilla).
  • The lumbar plexus is formed by the ventral rami of L1–L5 spinal nerves with a contribution of T12 form the lumbar plexus.
  • This plexus lies within the psoas major muscle.
  • It is interconnected with the lower part of sacral plexus.
  • In addition, the celiac plexus serves the internal organs, and Auerbach's plexus serves the gastrointestinal tract.

• Autonomic Plexuses

  • The autonomic plexuses include the cardiac plexus, the pulmonary plexus, the esophageal plexus, and abdominal aortic plexus, and the superior and inferior hypogastric plexuses.
  • The cardiac plexus is a plexus of nerves situated at the base of the heart that innervates the heart.
  • The pulmonary plexus is an autonomic plexus formed from pulmonary branches of vagus nerve and the sympathetic trunk.
  • The esophageal plexus and the cardiac plexus contain the same types of fibers and are both considered thoracic autonomic plexus(es).
  • The inferior hypogastric plexus (pelvic plexus in some texts) is a plexus of nerves that supplies the viscera of the pelvic cavity.

• Brachial Plexus

  • The brachial plexus is formed by the four lower cervical spinal nerves and the first thoracic spinal nerve.
  • The brachial plexus proceeds through the neck, the axilla (armpit region), and into the arm.
  • Lesions on the brachial plexus can lead to severe functional impairment.
  • The brachial plexus is divided into roots, trunks, divisions, cords, and branches.
  • The right brachial plexus with its short branches, viewed from the front.

• Injuries to Nerves Emerging from the Brachial Plexus

  • Brachial plexus injuries, or lesions, are caused by damage to those nerves.
  • But in general, brachial plexus lesions can be classified as either traumatic or obstetric.
  • The brachial plexus may be injured by falls from a height on to the side of the head and shoulder, whereby the nerves of the plexus are violently stretched.
  • Cervical (C5-C8) and thoracic (T1) comprise the brachial plexus, which is a nerve plexus that provides sensory and motor function to the shoulders and upper limbs.
  • Describe the effects of injuries to the nerves of the brachial plexus

• Cervical Plexus

  • The cervical plexus is the plexus of the ventral rami of the first four cervical spinal nerves.
  • The cervical plexus is a plexus of the ventral rami of the first four cervical spinal nerves located from the C1 to C4 cervical segment in the neck.
  • Nerves formed from the cervical plexus innervate the back of the head, as well as some neck muscles.
  • The cervical plexus has two types of branches: cutaneous and muscular.
  • The great auricular nerve originates from the cervical plexus and is composed of branches from spinal nerves C2 and C3.

• Lumbar Plexus

  • The lumbar plexus is a nerve plexus in the lumbar region of the body that forms part of the lumbosacral plexus.
  • This plexus lies within the psoas major muscle.
  • Nerves of the lumbar plexus serve the skin and the muscles of the lower abdominal wall, the thigh, and external genitals.
  • Femoral nerve: This is the largest and longest of the plexus' nerves.
  • An image of the lumbar plexus with its nerves highlighted in yellow.

• Nerve and Blood Supply

  • The articular and epiphyseal branches of the neighboring arteries form a periarticular arterial plexus.
  • Numerous vessels from this plexus pierce the fibrous capsule and form a rich vascular plexus in the deeper part of the synovial membrane.

• Submucosa

  • It contains Meissner's plexus, an enteric nervous plexus, situated on the inner surface of the muscularis externa.
  • Tiny parasympathetic ganglia are scattered around forming the submucosal plexus (or "Meissner's plexus") where preganglionic parasympathetic neurons synapse with postganglionic nerve fibers that supply the muscularis mucosae.

• Function and Physiology of the Spinal Nerves

  • The last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1, combine to form the brachial plexus, or plexus brachialis, a tangled array of nerves, splitting, combining and recombining to form the nerves that subserve the upper limb region and upper back.
  • Although the brachial plexus may appear tangled, it is highly organized and predictable with little variation among people.
  • The anterior divisions of the lumbar, sacral, and coccygeal nerves form the lumbosacral plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic.
  • For descriptive purposes, this plexus is usually divided into three parts: lumbar plexus, sacral plexus, and pudendal plexus.