Other 1 Flashcards
Autonomic Nervous System is composed of structures associated with?
Internal Organs and Viscera, smooth muscle, and glandular epithelium
Autonomic Nervous System mediates?
Visceral reflexes through local circuits in the spinal cord and brainstem
Viscerosensory System conveys information about?
status of visceral organs and internal body conditions
Viscerosensory system functions in parallel with?
Somatosensory pathways
In Viscerosensory system, information is transmitted via?
Dorsal root ganglion neurons and CN 9 and 10
What are the two types of receptors in Viscerosensory system?
-Nociceptors
- Physiologic
What do Nociceptors respond to?
- Potential damage to tissue
- Presence of damaged tissue
Visceral pain is often described as?
diffuse and difficult to localize
-because low receptor density with large receptor fields
What do Physiologic receptors respond to?
Innocuous stimuli, monitoring the function of visceral structures on a continuing basis
Fibers of Viscerosensory
- General visceral Afferent
- Classified as type III and IV (Slow)
- Travel through sympathetic or parasympathetic pathways
Sympathetic Pathways convey info from?
Nociceptors
- pain
Parasympathetic Pathways convey info from?
Physiologic receptors
Viscerosensory fibers enter the spinal cord at a particular level that?
Receives GVE input from the same spinal levels
What type of information reach the level of consciousness? and what doesn’t?
- information related to pain reaches the level of consciousness
- visceral activity that enter the spinal cord doesn’t
What are the two target areas of viscerosensory system?
- Reticular Formation
- Nucleus of the Solitary Tract
What is Reticular Formation
Diffuse and ill-defined collection of nuclei spread among the structures of brainstem
What type of information does reticular formation receive?
Sympathetic and Parasympathetic Viscerosensory
Reticular Formation projects to?
Thalamus and Hypothalamus, which ultimately project to the cerebral cortex
Largest number of Reticular Formation terminate in?
Frontal lobe
What structure is responsible for alert or activate the cerebral cortex?
Reticular Formation
- reticulothalamic and thalamocortical
What does ascending reticular activating system consist of?
Reticulothalamic
Thalamocortical
Where are Nucleus of the Solitary Tract Located?
medulla
What information does Nucleus of the Solitary Tract receive?
Parasympathetic viscerosensory info
Where do Nucleus of the Solitary Tract project to?
- Brainstem nuclei that are involved in pharyngeal and laryngeal reflexes
- Central regulation of respiratory, cardiovascular, and GI functions
What is referred pain?
- Noxious stimuli that originate in a visceral structure arise from a somatic structure
- Convergence of somatic and visceral information onto dorsal horn neurons
What are the target tissues of Visceromotor System
Cardiac muscles
Smooth muscles
Glandular Epithelium
What type of influence do Sympathetic and Parasympathetic divisions typically have/
Antagonist
*Sympathetic division alone innervates target tissue of?
- Body wall and extremities
- Adrenal medulla
- Arterial blood vessels
Pathway from the Brainstem or Spinal Cord to the target tissues consists of?
Two neurons
Preganglionic Neurons
- Cell body in the CNS
- myelinated axon projects to autonomic ganglion where Postganglionic Neurons are
Postganglionic Neuron
- Cell body in an autonomic Ganglion
- unmyelinated axon projects to the target tissue
What is an exception in the sympathetic division?
Preganglionic neurons can synapse directly in adrenal medulla