Lecture 8 - Autonomics Flashcards
What are the 2 parts of autonomic nervous system?
Sympathetics
Parasympathetic
What are the 2 types of autonomic outflows?
Craniosacral outflow
Thoracolumbar outflow
What type of autonomic outflow is sympathetic fibres?
Thoracolumbar outflow
What type of autonomic outflow is parasympathetic fibres?
Craniosacral outflow
What are the spinal nerve roots that form the thoracolumbar outflow?
What type of autonomic fibres are these?
T1 - L2
Sympathetic fibres
What are the spinal nerve roots that form the Craniosacral outflow?
What type of autonomic fibres are these?
4 cranial nerves (1973)
Parasympathetic fibres
How do the sympathetics run from the spinal cord to their target location? (Thoracolumbar outflow)
Preganglionics leave Thoracolumbar spin at T1/T2 level
They ascend in the sympathetic chain/trunk up the thorax and neck until they reach the cervical ganglion
This then synapses to the postganglionic sympathetic neurone
The postganglionic sympathetic neurone associates with the internal and external carotid arteries forming a plexus around them
The carotids carry them to their location/target tissues
Which part of the face do sympathetic nerves associating with the internal carotid artery supply?
Eye and orbit
Which 2 muscles of the eye/orbit are under sympathetic innervation (superior cervical ganglion)?
Dilator pupillae (smooth muscle)
Levator Palpibrae superioris (smooth muscle portion)
What is the function of levator palpibrae superioris?
What are the 2 portions of it and what are their 2 different innervations?
Retracts eyelid
Skeletal muscle portion = (Occulomotor III) main portion
Smooth muscle portion = superior cervical ganglion (sympathetics)
Which part of the face do sympathetic nerves associating with the external carotid artery supply?
Sweat glands on head and neck
What are the branches of the external carotid artery?
Superior thryoid.a
Ascending pharyngeal.a
Lingual.a
Facial.a
Occipital.a
Posterior auricular. a
Maxillary.a
Superficial temporal a.
What is a first order neurone?
The neurone/central pathway connecting the hypothalamus to the sympathetic nerves/sympathetic preganglionic
What is a 2nd order neurone?
The preganglionic sympathetic neurone that is outside the CNS within the sympathetic chain which synapses with the superior cervical ganglion
What is a third order neurone?
Sympathetic postganglionic neurone following the superior cervical ganglion that associates with the external and internal carotid arteries
Look at the last slide and label the neurones and other structure:
1 = first order neurone
2 = second order neurone
3 = superior cervical ganglion
4 = third order neurone
What are some pathologies that can affect the sympathetic nerves to the head and neck?
Lung cancers that invade sympathetic trunk
Common or internal carotid artery dissection (stretch’s nerves/3rd order neurones) or aneurysm
What is the name of the collection of signs and symptoms indicating interruption to sympathetic innervation to face and eye?
Horners syndrome
What are the 4 key clinical signs indicating Horners syndrome/interruption of sympathetic innervation to face and eye?
Partial Ptosis
Miosis
Anhidrosis
Enophthalmus
What is partial Ptosis?
Partial drooping of eye
What is miosis?
Constricted pupil
What is anhidrosis?
Lack of sweating
What is enophthalmus?
Apparent sinking of eye
Why does interruption of sympathetic innervation to face and eye cause partial Ptosis not full Ptosis?
Sympathetics supply the smooth muscle portion of the levator Palpebrae superioris which is the minority of LPS
The occulomotor nerve (III) innervates the MAIN SKELETAL portion
How many cranial nerves carry parasympathetic nerve fibres with them?
4
What are the 4 cranial nerves which carry preganglionic parasympathetic nerve fibres with them?
Vagus (X)
Glossopharyngeal (IX)
Facial nerve (VII)
Occulomotor (III)
What is the way to remember which 4 cranial nerves carry preganglionic parasympathetic nerve fibres with them?
Remember 1973
1 = 10 X
9 = IX
7 = VII
3 = III
How does the parasympathetic fibres to the head and neck run?
Parasympathetic nuclei in the brainstem
Preganglionic axons leave brainstem and run alongside with their associate cranial nerve
Preganglionic neurone eventually comes away from its cranial nerve and synapses with the cell body of the postganglionic parasympathetic neurone which leads to the target tissues by the distal branches of the Trigeminal nerve
What is the name of the preganglionic cell body of the parasympathetic nervous system that leads to the Occulomotor nerve (III)?
Edinger Westphal nucleus
What is the name of the postganglionic cell body of the parasympathetic nervous system that follows on from the Occulomotor nerve (III)?
Ciliary body
What is the target tissues of the parasympathetic fibres leading from the cillary body?
Sphincter/constrictor pupillae
Ciliary muscle (fattens lens)
What is the name of the preganglionic cell body of the parasympathetic nervous system that leads to the Facial nerve (VII)?
Superior Salivary Nucleus
What is the name of the postganglionic cell body of the parasympathetic nervous system that leads to the Facial nerve (VII)?
Pterygopalatine
Submandibular
What is the target tissues of the parasympathetic fibres leading from the Pterygopalatine body and submandibular body?
Lacrimal gland
Nasal + Mucosal gland
Salivary glands (sublingual + submandibular) NOT PAROTID
What is the name of the preganglionic cell body of the parasympathetic nervous system that leads to the Glossopharyngeal nerve (IX)?
Inferior salivary nucleus
What is the name of the postganglionic cell body of the parasympathetic nervous system that leads to the Glossopharyngeal nerve (IX)?
Otic
What is the target tissues of the parasympathetic fibres leading from the Otic body?
Salivary gland (Parotid)
What are the target tissues of the vagus nerve?
Mucosal glands
Smooth muscle in respiratory system
Smooth muscle in GI tract
Cardiac muscle
What is special about the cells bodies related to the vagus nerve?
Preganglionic = Dorsal Motor Nucleus
Postganglioncs = no named ganglia
Describe the pupillary light reflex:
Light shone in eye
Sensory signal sent along optic nerve (II)
Branch from optic nerve (II) goes to Pre-tectal nucleus in Brainstem
Pre-tectal nucleus sends signals to both Edinger-Westphal nuclei on both the left and right and side
Then parasympathetic fibres sent along with Occulomotor nerve (III) to the cillary body
Signal sent from cillary body to the sphincter pupillae
What are the 2 types of pupillary light reflex?
Direct
Consensual
Where is the lesion in this patient?
Light shone in right eye, Right pupil doesn’t constrict but LEFT pupil does. Light shone in LEFT eye, LEFT pupil constricts but the RIGHT pupil does not?
Right Occulomotor Nerve (III)
What 2 branches of the facial nerve do parasympathetic fibres associate with?
Greater Petrosal
Chorda tympani
What parasympathetic ganglia is associated with the greater petrosal branch of the Facial nerve (VII)?
Pterygopalatine ganglion
What parasympathetic ganglia is associated with the Chorda tympani branch of the Facial nerve (VII)?
Submandibular ganglion
How does the CNIX run?
Medulla -> posterior cranial fossa -> Jugular foramen -> carotid sheath
What are the parasympathetic is associated with the Glossopharyngeal nerves (CNIX)?
Preganglionics run to Otic
Postganglionics run with aurocilotemporal nerve to supply parotid gland
How do the parasympathetic run with the Vagus nerve (X)?
Medulla -> posterior cranial fossa -> jugular Foramen -> carotid sheath
