Eye Flashcards
Autonomic Innervation of the Eye
pupillary response to light involves both sympathetic and parasympathetic divisions of the autonomic nervous system. Pupil dilatation in response to low light illumination is predominantly accomplished by an increase in sympathetic activity. Constriction of pupils in response to high light levels results predominantly from an increase in parasympathetic activity.
Sympathetic eye will what
Dilate
Parasympathetic eye will what
Constrict
Sympathetic nerves control the ____ causing the pupil to dilate.
iris dilator muscle
Sympathetic nerves innervate vascular muscle causing ___ to constrict.
blood vessels
[Symp] Preganglionic nerves arise in the ___ and travel upwards in the sympathetic chain synapsing in the superior cervical ganglion
upper thoracic spinal cord
[Symp] Preganglionic nerves arise in the upper thoracic spinal cord and travel upwards in the sympathetic chain synapsing in the ____
superior cervical ganglion
___ is the
neurotransmitter released by pre-ganglionic nerves for both.
Acetylcholine
[Symp] Postganglionic nerves originate at the ___and travel through the internal carotid plexus to the dilator muscle of the iris.
superior cervical ganglion
[Symp] Postganglionic nerves originate at the superior cervical ganglion and travel through the ___ to the dilator muscle of the iris.
internal carotid plexus
______ is the neurotransmitter released by postganglionic nerves
Noradrenaline
[Symp] Noradrenaline is the neurotransmitter released by postganglionic nerves and activates ____ causing the dilator muscle to contract and the pupil to dilate and increasing the amount of light entering the eye.
alpha1-adrenoceptors
[Symp] Noradrenaline is the neurotransmitter released by postganglionic nerves and activates alpha1-adrenoceptors causing the dilator muscle to_____ and the pupil to dilate and____ the amount of light entering the eye.
contract
increasing
[Paras] Parasympathetic nerves control the muscle cells of the iris sphincter muscle – the ____
sphincter pupillae.
[Paras] sphincter pupillae is shape muscle cells which cause pupil constriction when they contract.
circular
[Paras] _____ is circular muscle cells which cause pupil constriction when they contract.
sphincter pupillae
[Paras] _____(also known as the oculomotor nerve) conveys preganglionic nerves to the ciliary ganglion.
Cranial nerve III
[Paras] Cranial nerve III (also known as the oculomotor nerve) conveys preganglionic nerves to the ___
ciliary ganglion.
[Paras] Postganglionic nerves travel with the short ciliary nerves and innervate the _____muscle which causes a narrowing of the aperture of the iris and a reduction in the amount of light entering the eye.
sphincter pupillae
[Paras] Postganglionic nerves travel with the short ciliary nerves and innervate the sphincter pupillae muscle which causes a narrowing of the-____ of the iris and a reduction in the amount of light entering the eye.
aperture
[Paras] Postganglionic nerves travel with the short ciliary nerves and innervate the sphincter pupillae muscle which causes a____ of the-____ of the iris and a reduction in the amount of light entering the eye.
narrowing
aperture
[Paras] Acetylcholine is the neurotransmitter released by both pre-ganglionic (acts on___
receptors) and postganglionic (acts on____receptors) nerves.
nicotinic
muscarinic M3
Atropine
competitive muscarinic receptor antagonist
Edrophonium
short acting acetylcholinesterase inhibitor
Combine reversibly with acetylcholinesterase
minutes
diagnose myasthenia gravis
Increase ACh -> contraction
Pilocarpine
muscarinic receptor agonist
Apraclonidine
alpha-2-adrenoceptor agonist and weak alpha-1-adrenoceptor agonist
Phenylephrine
alpha-1-adrenoceptor agonist