Posterior Triangle and Suboccipital Region


Autonomics of Head and Neck



Download 1.16 Mb.
Page5/7
Date07.02.2017
Size1.16 Mb.
1   2   3   4   5   6   7

Autonomics of Head and Neck


From MNMedWiki

Jump to: navigation, search

Neuronal Modalities

Input:Sensory:Afferents



  • Somatosensory: pain, temperature, muscle tendon stretch

    • involve neurons with cell body in sensory ganglion- located near CNS

    • peripheral process: picks up sensory info

    • central process: carries info to brain

    • action potentials heading in

  • Visceral Sensory: BP, gut, other viscera

    • similar to somatosensory

  • Special senses: each different

Output:Efferents

  • Motor neurons

    • responsible for movement

    • innervate muscles

    • cell bodies located within CNS-> send axons out-> synapse w/ muscle

    • action potentials heading out

    • activity in neurons make muscles contract

  • Autonomics

    • two neuron system

      • preganglionic neuron: cell body in CNS (brain or spinal cord)

      • ganglionic neuron: cell body in autonomic ganglion

    • Sympathetic

      • cell bodies in thoracic and lumbar spinal cord

      • ganglia near CNS

      • Head: cells in upper thoracic cord

        • axons leave cord via ventral root and join sympathetic chain

        • axons ascend in sympathetic chain and synapse at superior cervical ganglion

        • postganglionics travel on anything and everything (other nerves, carotid, etc. and follow arterial system through head)

    • Parasympathetic

      • cell bodies in brainstem or sacral spinal cord (cranial-sacral system)

      • ganglion near effector organ (structure it is controlling)



Parasympathetics'>Sympathetics

Parasympathetics

originate in upper thoracic spinal cord

originate with III, VII, IX, or X

short pregangiolic neuron

long preganglionic neuron

ascends to head via sympathetic chain

promiscuous course (jump around)

synapse in cervical ganglia

synpase in local ganglia

long postganglionic neuron

short postganglionic neuron



Parasympathetics

Ciliary ganglion



  • Originate in accessory oculomotor nucleus (edinger-westphal)

  • Travel via CNII

    • axons exit via oculomotor n. from brain

    • runs through middle cranial fossa in wall of cavernous sinus

    • passes through superior orbital fissure

    • branches-> inferior branch carries parasympathetic root to ciliary ganglion

  • Preganglionics synapse in ciliary ganglion

    • Travel via short ciliary nn. to eye

    • runs in coroid to front of eye

  • Postganglionics synapse in:

    • ciliary muscle → contraction → thicken lens → close vision

    • iris sphincter → contraction → close pupil → close vision

Pterygopalatine ganglion

  • Originate in superior salivatory nucleus

  • Travel via CNVII

    • enters temporal bone through internal acoustic meatus

    • travels through geniculate ganglion (no synapse)

    • travels through hiatus of greater petrosal n.

    • runs across floor of middle cranial fossa

    • joins deep petrosal (carrying sympathetics from internal carotid)

    • becomes n. of pterygoid canal

  • Preganglionics synapse in pterygopalatine ganglion

    • Travel via branches of V2 and V1 to lacrimal gland

      • Postganglionics synapse in lacrimal gland → salivation

    • Travel via nasopalatine n. and others to nasal mucosa and paranasal sinuses

      • Postganglionics synapse in mucosa → ↑ secretion & fluidity

    • Travel via greater and lesser palatine nn. to palate mucosa (hard and soft)

      • Postganglionics synapse in mucosa → ↑ secretion

Submandibular ganglion

  • Originate in superior salivatory nucleus

  • Travel via CNVII

    • enters temporal bone through internal acoustic meatus

    • travels through geniculate ganglion (no synapse)

    • gives off chorda tympani

    • exits skull via pterotympanic fissure and joins lingual n.

  • Preganglionics synapse in submandibular ganglion

    • Travel via lingual n.

  • Postganglionics synapse in submandibular & sublingual glands → ↑ secretion & fluidity

Otic ganglion

  • Originate in inferior salivatory nucleus (lower brainstem)

  • Travel via CNIX

    • exits skull via jugular foramen (along w/CNX, CNXI, and internal jugular v.)

    • pass through superior and inferior ganglion of IX

    • tympanic n. branches

    • passes through tympanic plexus

    • travels along floor of middle cranial fossa

    • becomes lesser petrosal n.

    • travels through infratemporal fossa

  • Preganglionics synapse in otic ganglion

    • Travel via auriculotemporal n.

  • Postganglionics synapse in parotid gland → ↑ secretion & fluidity

Sympathetics

Cervical ganglion



  • Originate in intermediolateral cell column in upper thoracic cord

  • Travel via ventral root-> white rami-> sympathetic chain

  • Synapse in superior cervical ganglion

  • Travel via internal carotid and a variety of nerves (e.g. short and long ciliary n.; sometimes with parasympathetics, sometimes not)

  • Postganglionics synapse in:

    • iris dilator → contraction → opens pupil → far vision

    • superior & inferior tarsal mm. → contraction → opens eyelid

    • blood vessels → vasoconstriction

    • sweat glands → ↑ secretion

    • hair of head and face → piloerection

    • salivary glands → ↓ secretion & ↑ viscosity

    • mucosa of respiratory and alimentary tracts → ↓ secretion

    • heart → ↑ contractility → ↑ stroke volume → ↑ cardiac output





Share with your friends:
1   2   3   4   5   6   7


The database is protected by copyright ©dentisty.org 2019
send message

    Main page