Eyes/Ears Flashcards
What are the names of the layers of the eyeball?
Fibrous tunic, uveal tract, and retina
What are the parts of the uveal tract of the eyeball?
Iris, ciliary body, choroid, and pupil
What are the receptor neurons of the second cranial nerve?
Rod and cone photoreceptor cells
What is the function of the rod cell?
Provide vision in dim light conditions
What is the function of the cone cell?
Provide vision in bright light conditions and mediate color vision
What is the most numerous photoreceptor cell?
Rod cell
What forms the optic nerve?
Axons of ganglion cells
What is the location of the anterior chamber of the eyeball?
Between the cornea and iris
What is the location of the posterior chamber of the eyeball?
Between the iris and lens
What is contained in the anterior chamber of the eyeball?
Aqueous humor
What is the name given to the chamber behind the lens?
Vitreous chamber
What is the location of the vitreous chamber?
Behind the lens, in front of the retina
What fills the vitreous chamber?
Vitreous body
What are the functions of the vitreous body?
Maintain retinal curvature; allow minimal light distortion from lens to retina
What are the common characteristics in origin and insertion of all rectus extraocular muscles?
They all originate from a common annular tendon in the orbit
They all insert into the sclera in front of the coronal equator of the eyeball
What is the common characteristic regarding the insertion of both oblique extraocular muscles?
Both insert onto sclera on the lateral margin of the eyeball behind the coronal equator
What is the source of innervation of the specific intrinsic eye muscles?
Parasympathetic fibers from oculomotor nerve-ciliaris, sphincter pupillae sympathetic fibers from internal carotid artery plexus-dilator pupillae
What are the two unique features of the fourth cranial nerve?
It is the only cranial with an apparent origin from the dorsal surface of the brain; it is the only cranial efferent nerve to decussate within the midbrain from its nucleus
Visceral efferent fibers conveyed in the third cranial nerve originate from which nucleus?
Accessory oculomotor nucleus of Edinger/Westphal
What is the location of synapse for preganglionic parasympathetic efferent fibers of the third cranial nerve?
Ciliary ganglion
Postganglionic parasympathetic efferent fibers of the third cranial nerve are carried in which nerve?
Short ciliary nerve
What is unique about the vascular supply of the retina?
A single vessel supplies it
What vessel supplies the inner tunic of the eyeball?
Central artery of the retina
What is the name given to the palpable posterior projection corresponding to the triangular fossa of the auricle?
Eminentia triangularis
