sympathetic trunk

Examples of sympathetic trunk in the following topics:

• Autonomic Plexuses

  • Autonomic plexuses are formed from both sympathetic and parasympathetic fibers and innervate visceral organs to regulate overall activity.
  • It is formed by the superior cardiac branch of the left sympathetic trunk and the lower superior cervical cardiac branch of the left vagus nerve.
  • Pulmonary: The pulmonary plexus is an autonomic plexus formed from pulmonary branches of vagus nerve and the sympathetic trunk.
  • Esophageal: The esophageal plexus is formed by nerve fibers from two sources: branches of the vagus nerve and visceral branches of the sympathetic trunk.
  • This section of the sympathetic trunk shows both the celiac and the hypogastric plexus.

• Cervical Plexus

  • There is anastomosis with the accessory nerve, hypoglossal nerve, and sympathetic trunk.

• Overview of the Spinal Nerves

  • The dorsal ramus contains nerves that serve the dorsal portions of the trunk; it carries visceral motor, somatic motor, and somatic sensory information to and from the skin and muscles of the back (epaxial muscles).
  • The ventral ramus contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs (hypaxial muscles); they carry visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs.
  • The first and second, and sometimes the third and fourth, lumbar nerves are each connected with the lumbar part of the sympathetic trunk by a white ramus communicans.
  • The smaller part of the fourth joins with the fifth to form the lumbosacral trunk, which assists in the formation of the sacral plexus.

• Horner's Syndrome

  • Horner's syndrome presents with drooping eyelids and pupil constriction, and is indicative of a problem in the sympathetic nervous system.
  • Horner's syndrome indicates a problem with the sympathetic nervous system, a part of the autonomic nervous system .
  • Partial ptosis: drooping of the upper eyelid from loss of sympathetic innervation to the superior tarsal muscle (Müller's muscle)
  • Loss of ciliospinal reflex: dilation of the pupil in response to pain applied to the neck, face, and upper trunk
  • Sympathetic and parasympathetic innervation of the pupil.

• Lymph Trunks and Ducts

  • There are four sets of of lymph trunks that are paired with a right and left half, and one unpaired trunk:
  • Lumbar lymph trunks- the lower pair of lymph trunks, which drain lymph fluid from the legs and pelvic region and kidneys.
  • Intestinal lymph trunks—the unpaired lymph trunk that receives chyle (lymph mixed with fats) from the intestines, which typically has a high fatty acid content.
  • There are two lymph ducts that recieve lymph from the lymph trunks.
  • Describe the types of lymph vessels and lymph trunks and their roles

• Sympathetic Nervous System

  • Sympathetic ganglia are the ganglia of the sympathetic nervous system that initiate "fight-or-flight" or stress-mediated responses.
  • Sympathetic ganglia are the ganglia of the sympathetic nervous system (see , red fibers).
  • An example of a sympathetic ganglion in a thoracic nerve is shown in .
  • Sympathetic ganglia are the tissue from which neuroblastoma tumours arise.
  • This intercostal nerve shows the sympathetic ganglion at the top left.

• Brachial Plexus

  • The brachial plexus is divided into roots, trunks, divisions, cords, and branches.
  • Each trunk then splits in two, to form six divisions: The anterior divisions of the upper, middle, and lower trunks and the posterior divisions of the upper, middle, and lower trunks.
  • The posterior cord is formed from the three posterior divisions of the trunks (C5–C8,T1).
  • The lateral cord is the anterior divisions from the upper and middle trunks (C5–C7).
  • The medial cord is simply a continuation of the anterior division of the lower trunk (C8, T1).

• Divisions of the Autonomic Nervous System

  • The autonomic nervous system (ANS) contains two subdivisions; the parasympathetic (PSNS) and sympathetic (SNS) nervous systems.
  • Sympathetic and parasympathetic divisions typically function in opposition to each other.
  • The sympathetic division typically functions in actions requiring quick responses.
  • Many think of sympathetic as "fight or flight" and parasympathetic as "rest and digest" or "feed and breed. "
  • Distinguish between the parasympathetic and sympathetic subsystems of the autonomic nervous system

• Autonomic Interactions

  • The sympathetic and parasympathetic autonomic nervous systems cooperatively modulate internal physiology to maintain homeostasis.
  • Sympathetic and parasympathetic divisions typically function in opposition to each other (, red indicates sympathetic pathways and blue indicates parasympathetic pathways).
  • The sympathetic division typically functions in actions requiring quick responses.
  • Consider sympathetic as "fight or flight" and parasympathetic as "rest and digest" or "feed and breed. "
  • Some typical actions of the sympathetic and parasympathetic systems are listed below.

• Sympathetic Responses

  • The sympathetic division of the autonomic nervous system maintains internal organ homeostasis and initiates the stress response.
  • The sympathetic nervous system is responsible for regulating many homeostatic mechanisms in living organisms.
  • Some evolutionary theorists suggest that the sympathetic nervous system operated in early organisms to maintain survival since the sympathetic nervous system is responsible for priming the body for action.
  • One example of this priming is in the moments before waking, in which sympathetic outflow spontaneously increases in preparation for activity.
  • His theory states that animals react to threats with a general discharge of the sympathetic nervous system, priming the animal for fighting or fleeing.