Vision Flashcards
Why do we have eyebrows?
Shading the eye
Preventing perspiration from reaching the eye
What muscle depresses the eyebrow?
Orbicularis muscle
What muscle moves the eyebrows medially?
Corrugator muscles
The course hairs that overlie the supraorbital margins form the…
Eyebrows
What are the palpebrae?
Eyelids
What is the function of the palpebrae?
Protect the eye anteriorly
What does the palpebral fissure do?
Separate the eyelids
What supports the eyelids internally?
The tarsal plates of connective tissue
What elevates the upper eyelid?
Levator palpebrae superioris
What is the conjunctiva?
The transparent membrane that:
-Lines the eyelids as the palpebral conjunctiva
-Covers the whites of the eyes as the occlar conjunctiva
-Lubricates and protects the eye
What is conjunctivitis?
Pink eye caused by the swelling of the conjunctiva
What does the lacrimal gland do?
It produces and secretes tears aka lacrimal secretions
True or false: Tears flow up and around the eyeball?
False- Tears flow down and across the eyeball
What is the role of the lateral rectus muscle?
Moves eyes laterally
What Cranial nerve controls the lateral rectus muscle?
VI (Abducens)
What does the medial rectus muscle do?
Moves the eyes medially
What cranial nerve controls the medial rectus muscle
III (occulomor)
What does the superior rectus muscle do?
Elevate the eyes and turns it medially
What cranial nerve controls the superior rectus muscle?
III (oculomotor)
What does the inferior rectus muscle do?
Depresses the eye and turns it medially
What cranial nerve controls the inferior rectus muscle?
III (oculomotor)
What does the inferior oblique muscle do?
Elevates eye and turns it laterally
side eye lmao
What cranial nerve controls the inferior oblique?
III (oculomotor)
What muscle depresses the eye and turns it laterally?
Superior oblique
Sneak peak lol
What cranial nerve controls the superior oblique?
IV (trochlear)
What happens when the sphincter pupillae muscle contracts? What ANS controls this?
Pupil size decreases/constricts
What muscles make up the iris?
Sphincter pupillae
Dilator pupillae
What happens when the dilator pupillae muscle contracts? What ANS system controls this?
Pupil size increases/dilates
Sympathetic NS
What is the optic disc?
The site where the optic nerve leaves the eye and there is a lack of photoreceptors aka blind spot
What is the location of ganglion cell axons?
Run along the inner surface of the retina and leave the eye as the optic nerve
What forms the optic nerve?
Axons of retinal ganglion cells
Which fibers decussate at the optic chiasm?
Medial fibers of the optic nerve
Where do most fibers of the optic tract continue to…
The other optic tract fibers….
Lateral geniculate body of the thalamus
end in the superior colliculi and pretectal nuclei
What is the role of the superior colliculi?
Initiating visual reflexes
What is the role of the pretectal nuclei?
Involved in pupillary reflexes
Optic radiations travel from the ______ to the _______
Thalamus, visual cortex
What is melanopsin?
Circadian Pigment- Sets daily biorhythms/biological clock
True or false: A small subset of visual fibers contain melanopsin
True
True or false: A small subset of visual fibers contain melanopsin
True
Where are rods located?
Mostly peripheral retina
Where are cones located?
Mostly central retina
Which is more numerous?
a) Rods
b) Cones
C) They are the same
A) Rods
For every cone, there are 20 rods
True or false: Color vision can be seen in rods via three visual pigments?
False- Colour is picked up by cones while non colour vision of visual pigment is rods
I am highly sensitive and I function in dim light. I am a….
ROD
I am not very sensitive and I function in bright light. I am a…
CONE
