Unit 3 Flashcards
Eyelashes, eyebrows, blinking is a _ structure
protective
Obicularis oculi
(CLOSES upper and lower lids)
Levator palpebrae superioris
OPENS upper eyelid
Glands of Krause
BENEATH the palpebral conjunctiva (between fornix and edge of tarsus)
Glands of Wolfring
near UPPER border of superior tarsal plate and LOWER border of inferior tarsus
Lacrimal gland is for the _ of _
production of tears
Tears move by (a) ____ and (b) into __ passage
a. blinking
b. nasal passage
Valve of Rosenmuller is at the (start/end) of the __ __
start of the lacrimal sac
Valve of Hasner is at the (start/end) of _ duct (prevents blackflow of tears)
End of the NASALLACRIMAL`
2 purposes of tears
- lubricates eye
- protects agains microbes
Tear FILM is responsible for 4 things
- comfort
- protection
- epithelial health (corneal and conjunctival)
- refracts for vision
Tear FILM has 3 layers (hint = LAM)
- Lipid
- Aqueous
- Mucous
Lipid layer
Tear film layer that helps STOP EVAPORATION
Aqueaous Layer
Layer that washes away foreign bodies
Mucous Layer
Reduces friction
Iris Sphincter
when the circular muscle contracts
and
the radial muscle relaxes
then pupil REDUCES in size
Iris Dilator
spoke-shape
when the radial muscle contracts and the circular muscles relaxes
PUPIL OPENS WIDER
Radial muscle does what to pupil
Opens pupil wider
Circular muscle does what to pupil
Reduces pupil
Can the radial and circular muscles work at the same time?
No, they are antagonistic
ParaSYMPATHETIC
rest and digest (reading: pupil constricts)
SYMPATHETIC
fight and flight reflect reaction to stress (to let more light in)
Pupils are impacted by these 4 things
- light
- accommodation
- age
- injury
OculoMOTOR CN3 is a (1) _ nerve.
If it is damaged, the pupil will (2) _
- vulnerable
- dilate
AFFERENT Pathway is the RED pathway (goes from _ to _)
from EYE to BRAIN
(red pathway)
EFFERENT Pathway is the BLUE Pathway (goes from _ to _)
from BRAIN to BOTH EYES
MEIBOMIAM glands - if oil (meibum) is thickened, it can indicate _ disease
dry eye disease
GLAUCOMA occurs when there is damage to the ___ cell layer which leads to (thinning or thickening) of the fiber layer
ganglion cell layer
thins fiber layer
GLAUCOMA results in loss of TISSUE within the optic nerve. See a ___ with a THINNER rim
DISC with a thinner rim
GLAUCOMA results in production of _ (mucus, aqueous, or lipid?) humour
aqueous humor
(flows FROM pupil TO anterior chamber)
When you have GLAUCOMA, the AQUEOUS humour is drained through (1) TM (=__ __), into the (2) S___’s canal, and into (3) v_ system
- trabecular meshwork
- Schlemm’s canal
- venous system
RODS: (1) _ goes through cells > photoreceptors > (2) c__ transformation > breaks (3)p_ down to release a (4) n___ impulse which sends signal through RETINA to GANGLION cell
- light
- chemical transformation
- breaks down PIGMENT
- nerve impulse
- retina
- ganglion cell
L cones - visual pigment that is the color _
L = red
M cones - visual pigment that is the color _
M = green
S cones - visual pigment that is the color _
blue
CONES have HIGHEST density in which area of the eye?
CENTRAL AREA (dense part of CONES)
RODS have HIGHEST density in which area of the eye?
dense in the peripheral RETINA
rhoDOPSIN is the name of the VISUAL pigment in rods or cones?
rods
Is rhoDOPsin more or less senstive to light than phoTOPsins?
More sensitive
BECAUSE
rhoDOPsins pick up signals in the dark
When multiple rods converge signals, SENSITIVITY is gained but what is lost?
Fine detail (or visual acuity)
MONOchromacy
no colour (only rods; no cones)
DIchromacy
two cones only
PROtanopia is a colour vision defect missing the _ cone opsin.
Red
DEUTERanopia is a colour vision defect missing the _ cone opsin.
Green
TRItanopia is a colour vision defect missing the _ cone opsin.
Blue
triCHROMacy is normal colour vision with how many cone opsins
3
2 forms of monoCHROMacy are
Cone monoCHROMacy (only cones)
Rod monoCHROMacy (only rods)
