7) Autonomic Innervation Flashcards
Is the ANS part of peripheral or central nervous system?
Peripheral
What parts of the brain can control/effect the ANS?
Central control from hypothalamus
Limbic system can have effects due to emotional response
What are the target tissues of the ANS?
Smooth muscle and glands
Which spinal cord segments provide sympathetic innervation to the head and neck?
T1 and T2
Describe the route of sympathetic nerve fibres to the head and neck:
Preganglionic fibres ascend up sympathetic chain to synapse at superior or middle ganglion. Post ganglion fibres ‘hitch hike’ on carotid arteries via carotid plexus
Where does the carotid plexus around external carotid artery end?
Face - sweat glands and BVs
Where does the carotid plexus around internal carotid artery end?
Eye (via ophthalmic artery) - tarsal muscle (contraction of eyelid) and dilator pupillae
How do sympathetic fibres get to the eyelid?
Oculomotor nerve
How do sympathetic fibres get to muscles of iris?
Trigeminal nerve branch
What is Horner’s syndrome?
What are some symptoms?
Interruption to sympathetic supply of head and neck
Miosis, partial ptosis, anhidrosis
What are some causes of Horner’s syndrome?
Carotid artery dissection
Apical lung tumour
What nerves do parasympathetic nerve fibres ‘hitch hike’ on?
Oculomotor, facial, glossopharyngeal and vagus
Describe the route of parasympathetic fibre associated with the oculomotor nerve:
(include what the fibres innervate)
Pass through ciliary ganglion, post ganglionic associated with trigeminal nerve branch, carried to sphincter pupillae and ciliary body (lens changes)
Describe the route of parasympathetic fibre associated with the glossopharngeal nerve:
(include what the fibres innervate)
Pass through otic ganglion, post ganglionic associated with trigeminal branch, carried to parotid gland
Describe the route of parasympathetic fibre associated with the vagus nerve:
(include what the fibres innervate)
Synapse near target tissue
Glands in laryngopharynx , larynx, trachea and oesophagus
Thorax and abdomen