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