11/5 Anatomy Flashcards
What controls the pupil diameter?
two opposing forces of dilation from the sympathetics; and constriction from CN III- Parasympathetics.
What would happen if you knock out CN III to the eye
it would dialate because you remove the parasympathetic innervation and only the sympathetic is left!
what gives general sensory info to the eye and face etc.
CN V (V-1 to the eye)
Describe the control of the retina reflex!! (the sensory, the motor)
Sensory is CN V-1 from cornea; Brainstem level pons CNS processing center; Motor CN VII (facial n. proper to orb occuli m.; consensual reflex (both eyes blink)
what cranial nerve senses light shined in your eye?
CN II
What CN would constrrict the eye when light is shined in?
CN III
CNIII lesion
eye moves down and out (only CNs IV and VI work); ptosis and midrisis
CN IV lesion
can not look in and down
CN VI lesion
double vision when looking laterally to side of lesion
The sphincter muscle of the face…to close the eye
Orbicularis oculi mucle
nerves of the Orbicularis oculi muscle
Facial nerve proper (CN VII)
the two muscles that keep the eyelid up:
levator palpegrae superioris muscle; Superior tarsal muscle
the nerve of the levator palpebrae superioris muscle:
Oculomotor nerve (CN III)
the nerve of the superior tarsal muscle:
sympathetics from T1 spinal cord!
what if I knock out the T1 sypathetics to the eye or the CNIII?
Ptosis: droopy eye-lid
How do I get sympathetics to the superior tarsal muscle?
pregaglionic nerve from T1 goes out ventral root, trunk, vetral ramus, white matter communicon, up the chain, synapse in the supperior cervical ganglion then wrap around the IJV and head into the head and along vessels to the eyes!
what is the gland in the supior lateral section above the eye?
Lacrimal gland
what is the funciton of the lacrimal apparatus/gland
Make tears!
Where do the tears drain?
dowy the sup./Inf. puncat and to the lacrimal canaliculli and to the lacrimal sac and to the nasolacrimal duct and to the nasal cavity!
what is the function of the tears?
to keep the eye from drying out, to wash it out and to help fight infection.
what innervates
the facial nerve CNVII - greater petrosal nerve.
describe the course of the greater petrosal nerve:
out the internal acoustic meatus with the facial nerve, then thorugh the greater petrosal hiatus, then towards the nose and through the pterygopalatine ganglion near the nasal cavity. then it jumps onto V-2 and then skips up to V-1 and then innervates the lacrimal gland!
waht are the layers of the eyeball?
the sclera/cornea; the choroid layer; the retina
What is the sclera?
the white of the eye: dense fibrous connective tissue
the transparent portion of the eyeball that is in front of the iris and the lens
The cornea
Function of the cornia
to refract in coming light
What innervates the cornea with sensory innervation
CN V-1