somatic nervous system

Examples of somatic nervous system in the following topics:

• Comparing the Somatic and Autonomic Nervous Systems

  • The peripheral nervous system includes both a voluntary, somatic branch and an involuntary branch that regulates visceral functions.
  • The peripheral nervous system (PNS) is divided into the somatic nervous system and the autonomic nervous system.
  • The somatic nervous system (SoNS) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.
  • The somatic nervous system controls all voluntary muscular systems within the body, and also mediates involuntary reflex arcs.
  • The somatic nervous system consists of three parts:

• Subdivisions of the Nervous System

  • The nervous system is comprised of two major subdivisions, the central nervous system (CNS) and the peripheral nervous system (PNS).
  • The PNS is further subdivided into the autonomic nervous system (ANS) and the somatic nervous system.
  • The somatic system has voluntary control of our movements via skeletal muscle.
  • The ANS is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
  • The enteric nervous system (ENS) controls the gastrointestinal system and is sometimes considered part of the autonomic nervous system.

• Micturition and the Micturition Reflex

  • Physiologically, micturition involves coordination between the central, autonomic, and somatic nervous systems.
  • The muscles controlling micturition are controlled by the autonomic and somatic nervous systems, which open the two sphincters during the voiding phase of micturition.
  • The external urethral sphincter (sphincter urethrae) is under somatic control and is consciously relaxed (and thus opened) during micturition.
  • The state of the micturition reflex system is dependent on both a conscious signal from the brain and the firing rate of sensory stretch fibers from the bladder and urethra.

• Function and Physiology of the Spinal Nerves

  • The peripheral nervous system (PNS) consists of the nerves and ganglia outside of the brain and spinal cord.
  • The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs.
  • The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.
  • The somatic nervous system consists of afferent and efferent nerves and is associated with the voluntary control of skeletal muscle movements.
  • The functions of the parasympathetic and sympathetic nervous systems are detailed.

• Cholinergic Neurons and Receptors

  • Acetylcholine (ACh) is an organic, polyatomic ion that acts as a neurotransmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms, including humans.
  • Acetylcholine is one of many neurotransmitters in the autonomic nervous system (ANS) and the only neurotransmitter used in the motor division of the somatic nervous system (sensory neurons use glutamate and various peptides at their synapses).
  • Acetylcholine has functions both in the peripheral nervous system (PNS) and in the central nervous system (CNS) as a neuromodulator.
  • In the peripheral nervous system, acetylcholine activates muscles and is a major neurotransmitter in the autonomic nervous system.
  • In the central nervous system, acetylcholine and its associated neurons form the cholinergic system.

• Autonomic Reflexes

  • In these cases, the body will interpret the afferent pain stimulus as somatic.
  • The autonomic nervous system (ANS, visceral nervous system, or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system.
  • These then subdivide into other areas and are also linked to ANS subsystems and nervous systems external to the brain.
  • The ANS is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS) that operate independently in some functions and interact co-operatively in others.
  • The enteric nervous system is also sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.

• Localization of Pain

  • Localization of pain is determined by whether the pain is superficial somatic, visceral, or deep somatic.
  • Nociceptive pain may also be divided into visceral, deep somatic, and superficial somatic pain.
  • Deep somatic pain is initiated by the stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae, and muscles, and is a dull, aching, poorly localized pain.
  • Examples of injuries that produce superficial somatic pain include minor wounds and minor (first degree) burns.

• Parasympathetic (Craniosacral) Division

  • Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system that lie near or within the organs they innervate.
  • Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system, blue fibers).
  • Because of its location, the parasympathetic system is commonly referred to as having craniosacral outflow, in contrast to the sympathetic nervous system, which is said to have thoracolumbar outflow.
  • The parasympathetic nervous system, shown in blue, is a division of the autonomic nervous system.
  • Describe features of the parasympathetic division of the autonomic nervous system

• Branches of Spinal Nerves

  • The dorsal ramus: Contains nerves that serve the dorsal portions of the trunk carrying visceral motor, somatic motor, and sensory information to and from the skin and muscles of the back.
  • The ventral ramus: Contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs carrying visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs.

• Somatic Sensory Pathways to the Cerebellum

  • A sensory system is a part of the nervous system responsible for processing sensory information.
  • A sensory system consists of sensory receptors, neural pathways, and the parts of the brain involved in sensory perception.
  • Commonly recognized sensory systems are those for vision, hearing, somatic sensation (touch), taste, and olfaction (smell).
  • It is part of the somatosensory system and runs in parallel with the dorsal spinocerebellar tract.
  • It is part of the somatosensory system and runs in parallel with the ventral spinocerebellar tract.