6.1 Autonomic Nervous System Flashcards
What is the autonomic nervous system?
Part of the peripheral nervous system that controls smooth muscle and glands
Describe the outflow of the sympathetic system?
Thoracolumbar outflow
T1-L2
Where can cell bodies of parasympathetic NS be found?
Lateral horn of grey matter of spinal cord
Describe the outflow of the parasympathetic NS
Craniosacral
Cranial 4
Sacral S2-4 = pelvic splanchnics
Where can cell bodies of parasympathetic NS be found?
Discrete collections of parasympathetic bodies in brainstem or within grey matter of sacral spinal cord
What are nuclei?
Discrete collections of parasympathetic cell bodies
What are the symptoms of Horner’s syndrome?
Partial ptosis
Constricted pupil
Anhidrosis
Why do you get partial ptosis in Horner’s syndrome?
Only lost the sympathetic innervation
Oculomotor nerve still innervating the bulk of the muscles
Why do you get a constricted pupil in Horner’s syndrome?
Lost the sympathetic effect of dilation
Miosis
What is the origin of sympathetic innervation?
Spinal cord T1-L2
Where are the important ganglia for sympathetic head and neck innervation?
Ganglia in cervical portion of sympathetic chain
- Superior cervical ganglion
- Middle cervical ganglion (neck and chest)
What do sympathetics of head and neck hitch hike on?
Blood vessels
- External and internal carotid
CN V
- Distally
What are the effector tissues of sympathetic innervation of head and neck?
Eye - Dilator pupillae
Eye lid - Superior tarsal muscle
Blood vessels
Sweat glands
What are the responses of sympathetic innervation to head and neck?
Pupil dilation
Assists lid retraction
Vasoconstriction
Sweating
Which cranial nerves carry parasympathetic fibres from the brainstem?
Oculomotor
Facial
Glossopharyngeal
Vagus
Describe the route of parasympathetic innervation to head and neck
Arise from brainstem from (4) parasympathetic nuclei Hitch hike on one of 4 CNs Ganglia - 4 Hitch hike on branches of CN V Target tissue
What are some parasympathetic target tissues in the head and neck?
Smooth muscle in the iris - constrictor Ciliary muscle - lens Lacrimal gland Mucosal glands in nasal/oral mucosa and respiratory tract Salivary glands
Name the 4 parasympathetic nuclei
Edinger Westphal
Superior salivary
Inferior salivary
Dorsal motor
Name the 4 parasympathetic ganglia
Ciliary
Submandibular
Pterygopalatine
Otic
Describe the route of parasympathetic CN III
EWN Hitch hike CN III Ciliary ganglion Hitch hike CN Va Eye - Ciliary body (lens) - Constrictor of the pupil
Which nuclei is involved in pupillary light reflexes?
Edinger westphal nuclei (left and right)
Describe the pupillary light reflex
Light in left pupil
Sensory afferent from left retina CN II
Some branches leave CN II to enter midbrain
Connection with EDW nuclei - left and right
Parasympathetic fibres from EDW leave brainstem
Hitch hike on CN III (left and right)
Pass via ciliary ganglion
Reach sphincter pupillae
What is the pupillary response in the contralateral eye called?
Consensual light reflex
What do parasympathetic nerves associated with CN III innervate?
Sphincter pupillae
Which two main branches of the facial nerve arise within the petrous bone?
Greater petrosal nerve
Chorda tympani nerve
What parasympathetic ganglia are associated with parasympathetics associated with CN VII?
Pterygopalatine
Submandibular
Describe the course of chorda tympani
Submandibular ganglion ->
Hitch hikes on CN V ->
Submandibular and sublingual salivary glands
Describe the route of the greater petrosal nerve?
Pterygopalatine ->
Hitch hikes on branches of CN V ->
Lacrimal gland, nasal and oral mucosal glands
What are some branches of CN IX?
Tympanic nerve - supplies sensory to middle ear
Lesser petrosal nerve
Which ganglion is associated with parasympathetic CN IX?
Otic
Where can the otic ganglion be found?
In infratemporal fossa
What do post ganglionic parasympathetics of CN IX hitch hike on?
Branch of CN Vc
What do parasympathetics of CN IX innervate?
Parotid gland
Describe the parasympathetic route of CN IX
Preganglionic parasympathetics from brainstem with CN IX Jugular foramen Tympanic nerve Tympanic plexus Lesser petrosal nerve -> foramen ovale Otic ganglion Post ganglionic parasympathetics on CN Vc Parotid gland
Describe the route of parasympathetic CN X
Medulla
Hitch hikes on CN X
Meets ganglion at or in target tissue
Target
What are the target tissues of parasympathetics of CN X?
Glands in laryngopharynx, larynx
Glands and smooth muscle of oesophagus and trachea
Heart
Smooth muscle and glands within respiratory and GI tract
What are the origins of parasympathetic NS in head and neck?
Brainstem
Which nerves do parasympathetic of head and neck hitch hike on?
CN III, VII, IX, X
How do post ganglionics of parasympathetic head and neck reach effector organs?
Branches of CN V
Except CN X
Name the parasympathetic ganglia
Ciliary
Pterygopalatine
Submandibular
Otic
What are the effector tissues of parasympathetic NS in head and neck?
Eye (sphincter pupillae and ciliary muscles) Lacrimal glands Mucosal glands Salivary glands Parotid gland
What are the parasympathetic responses in head and neck?
Constrict pupil
Accommodation reflex - lens shape
Glandular secretions - salivary and mucosal
Cardiac muscle and smooth muscle in resp and digestive system
What do parasympathetic fibres associated with CN IX innervate?
Parotid gland
Post ganglionic parasympathetic fibres typically hitch hike with branches of the..
Trigeminal nerve
