Ocular: Introduction Flashcards
Coronal plane
-Frontal plane
-Divides body into anterior and posterior
Transverse plane
-Horizontal plane/axial plane
-divides body into inferior and superior
Sagittal plane
-longitudinal plane/vertical plane
-divides body into left and right
X (horizontal axis) of the eye is responsible for
Elevation and depression
Y(anterior-posterior) axis of the eye is used for
-torsional movements
-extortion/intorsion
Z (vertical axis) of the eye is responsible for
-adduction/abduction
Bulbar
Pertaining to the surface of the eye
Palpebral
Pertaining to the surface of the lid
Three segments/chamber of the eye:
-anterior chamber
-posterior chamber
-posterior segment
Anterior chamber
-bounded in front by cornea
-posterior by iris and anterior surface of lens
Posterior chamber
-lies behind the iris and surrounds equator of the lens
-separating from ciliary body
Anterior and posterior chambers are….
Continuous with each other through the pupil
Both anterior and posterior chambers contain ________________ produced by the _____________
Aqueous humor, ciliary body
Aqueous humor provides…
Nourishment for the surrounding structures
Posterior segment
-largest space
-lies adjacent to the inner retinal layer and is bounded in by the lens
-contains gel-like substance, vitreous humor
Iridocorneal angle
-Circumferential region/space
-space between cornea and iris that regulates the flow of aqueous humor
Layers/tunics of the eye:
-fibrous tunic (tunica fibrosa)
-vascular tunic (tunica vasculosa)
-neural tunic (tunica interna)
Fibrous tunic
-cornea
-sclera
Vascular tunic
-iris
-ciliary body
-choroid
Neural tunic
Retina
Sclera
-opaque
-protects, shapes, and anchors muscles to the eye
Cornea
-transparent window for light refraction
-2/3rds total optical power of the eye
Iris
-acts as diaphragm to regulate light entering pupil
Ciliary body functions:
-accommodation
-aqueous humor production
-maintenance of zonules
Choroid
-provide nutrients/remove waste from outer retina
-passage of nerves/vessels
-absorption of excess light
-regulates emmetropization
Retina
-absorbs photons of light
-convert photons into neural signals
-rods/cones
-spatial encoding
-10 retinal layers
Optic nerve
-transmits all visual info to visual cortex
-neurological reflexes (light and accommodation)
-blind spot (secondary to absence of photoreceptors)
Anterior pole of the globe
The reference point used to describe any eye movements
Vitreous cavity takes up about ___ of the eye
80%
Function of the vitreous cavity
-holds retina against the choroid
-shock absorption
-metabolite storage (antioxidants)
-transmits and refracts light
Limbus is the…
Region where sclera transitions to cornea
Anterior segment contains:
Anterior chamber and posterior chamber
Anterior segment contains:
Anterior chamber and posterior chamber
