Session 6 - Autonomic Nervous System Flashcards
Is the autonomic nervous system part of the central or peripheral nervous system?
Peripheral nervous system
What are the general target tissues of autonomics?
Smooth muscle
Glands
Where does sympathetic outflow arise from?
Thoracolumbar region (T1-L2) of the spinal cord
Sympathetic outflow to the head and neck arises from which spinal segments specifically?
T1/T2 spinal segments
Where do preganglionic sympathetic fibres synapse?
The sympathetic chain
Preganglionic sympathetic fibres going to the head and neck synapse in which ganglia?
Superior and middle cervical ganglia
Describe the route of sympathetic nerves innervating the head and neck.
Sympathetic outflow to the head and neck arises from T1/T2.
Preganglionic sympathetic fibres ascending from the thorax, up the sympathetic chain to reach the neck.
Synapse in one of the upper cervical ganglia (superior or middle cervical ganglia).
Post ganglionic sympathetic fibres hitch hike on blood vessels to reach their target tissues.
Post ganglionic sympathetic fibres hitch hike on what structures to reach their target tissues?
Blood vessels (internal and external carotid arteries and their branches)
What are the functions of sympathetic nerves to the head and neck?
Pupillary dilation
Assists lid retraction
Sweating
Vasoconstriction
What are the effector tissues of sympathetics to the head and neck?
Dilator pupillae
Superior tarsal muscle
Blood vessels
Sweat glands
(Sympathetic nerves also innervate salivary and lacrimal glands, but their effect is to decrease secretions).
What pathologies can cause Horner’s syndrome?
Pathology involving the apex of the lung and internal carotid artery.
What are the three characteristics of Horner’s syndrome?
Partial ptosis
Miosis (constricted pupil)
Anhydrosis
Why does pathology in a lung apex (e.g. cancer) or the internal carotid artery cause Horner’s syndrome?
Causes interruption to sympathetic fibres and therefore autonomic dysfunction in the eye and face.
Which cranial nerves ‘carry’ parasympathetic fibres from the brainstem?
Oculomotor (CN III)
Facial (CN VII)
Glossopharyngeal (CN IX)
Vagus (CN X)
From what four parasympathetic nuclei do parasympathetic fibres arise from?
EDINGER WESTPHAL
Superior salivary
Inferior salivary
Dorsal motor
In what four parasympathetic ganglia do the pre ganglionic parasympathetic fibres synapse?
Ciliary
Pterygopalatine
Submandibular
Otic
Most post ganglionic sympathetic fibres hitch hike on what cranial nerve?
Trigeminal (CN V)
Parasympathetic fibres that run with the oculomotor nerve (CN III) arise from what nucleus?
Edinger Westphal
Pre ganglionic parasympathetic fibres running with the oculomotor nerve synapse at what ganglion?
Ciliary ganglion
What are the target tissues of post ganglionic parasympathetic fibres arising from the ciliary ganglion?
Sphincter pupillae
Ciliary body
Which two main branches of the facial nerve arise inside the petrous bone?
Greater petrosal nerve
Chorda tympani nerve
Which two parasympathetic ganglia are associated the facial nerve (CN VII)?
Pterygopalatine
Submandibular
Parasympathetic fibres synapsing in the pterygopalatine ganglion are associated with what nerve?
Greater petrosal nerve (branch of CN VII)
Parasympathetic fibres synapsing in the submandibular ganglion are associated with what nerve?
Chorda tympani nerve
At the point of the geniculate ganglion, what branch of CN VII arises?
Greater petrosal nerve
