Orbital Autonomics Flashcards
where do sympathetic nerve fibres for the eye leave the spinal cord?
T1 spinal nerve
where do sympathetics for the eye synapse?
the superior cervical sympathetic ganglion
where do post synaptic sympathetic axons for the eye enter after they synaose?
the internal and external carotid nerves which pass onto the carotid arteries
what carries the sympathetic axons into the orbit?
the ophthalmic artery
where do all parasympathetic axons leave the CNS?
cranial nerves 3,7,9 and 10 OR via sacral spinal nerves
what parasympathetic ganglion supplies the eye?
the ciliary ganglion
what cranial nerve contributes to the ciliary ganglion?
CN III
where is the ciliary ganglion located?
the bony orbit
what is CN III?
the oculomotor nerve
where does CN III connect with the CNS?
the junction of the midbrain and the pons
where does CN III exit the cranial cavity?
the superior orbital fissure
what two modalities does CN III carry?
somatic motor
parasympathetic
what does CN III carry somatic motor nerve to?
the majority of the extraocular muscles
what are the two divisions of CN III after it passes through the superior orbital fissure, and which is then part of the ciliary ganglion?
superior
inferior - this one
what supplies sensory innervation of the face?
the branches of the trigeminal nerve
where does the trigeminal nerve originate?
the lateral surface of the pons
what is another name for the corneal reflex?
blinking
what type of reflex is the corneal reflex?
sensory
what is the function of the corneal reflex?
to protect the eye
what are the three components of the corneal reflex?
sensory (afferent)
central
motor (efferent)
what happens in the sensory limb of the corneal reflex?
AP’s conducted from the cornea via CN V1 and taken to the trigeminal ganglion
travels along CN V to the pons
what are the central CNS connections involved in the corneal reflex?
connections between CN V and CN VII
what happens in the motor limb of the corneal reflex?
AP’s conducted from the brain via CN VII
to the palpebral part of orbicularis oculi = a blink