Ocular Parasympathetic Pathway

Question 1

Parasympathetic pathway begins in the

Answer 1

Midbrain, pons, medulla, and sacral spinal cord.

Question 2

The parasympathetic pathway for the ciliary muscle and iris sphincter originates in the

Answer 2

Edinger westphal nucleus within the midbrain

Question 3

The parasympathetic pathway for the lacrimal gland originates in the

Answer 3

Lacrimal nucleus of the pons

Question 4

Pupillary pathway that results in accommodation and pupil constriction (meiosis)

Answer 4

Visual sensory info travels to retina- optic nerve - optic chiasm - optic tract - Midbrain/pretectal nucleus - edinger westphal

Motor response from edinger westphal to the ciliary ganglion to the short ciliary nerves to the ciliary muscle (97%) and iris sphincter (3%)

Question 5

The autonomic nervous system is

Answer 5

Efferent. Motor

Question 6

Stimulation of the pupillary pathway results in

Answer 6

Contraction of the ciliary muscle and contraction of the iris sphincter, resulting in accommodation and miosis.

Question 7

How do parasympathetic fibers inner the lacrimal gland to stimulate lacrimation?

Answer 7

Preganglionic fibers exit the pons and travel with the CN VII to the greater petrosal nerve and vidian nerve

They synapse at the pterygopalatine ganglion (sphenopalatine ganglion)

Postganglionic fibers then travel with CN V2, the zygomatic nerve, to the communicating branch, the lacrimal nerve, then to the lacrimal gland.

Stimulation causes lacrimation

Question 8

Which 3 structures of the eye does the parasympathetic system innervate

Answer 8

Innervates the lacrimal gland to stimulate lacrimation
Innervates the pupillary sphincter to cause contraction
Innervates ciliary muscle to cause contraction