Special Senses: Vision Flashcards
Optic Nerve (2)
sensory for vision
Oculomotor (3)
Iris, ciliary body control, all eye muscles except the superior oblique and lateral rectus
Trochlear (4)
motor for superior oblique muscle
Abducens (6)
motor for lateral rectus muscle
Trigeminal (5)
general sensation of eye
Humans are sensitive to visible light. Visible light wavelength is…
380nm - 760nm
Conjunctiva
thin mucous membrane that covers the inside of the eyelid and the sclera, made of unkeratinized stratified squamous and stratified columnar epithelium with goblet cells
Goblet cells
modified epithelial cells that secrete mucous on mucous membranes
Eyelids
thin fold of skin that covers and protects the eye
Eye muscles
levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, lateral rectus(6), inferior oblique muscle, superior oblique muscle(4)
Cornea
transparent front part of the eye that covers the pupil, iris, and anterior chamber, refracts light
Sclera
opaque, fibrous, protective outer layer of the human eye, made from collagen and elastic fiber
Iris
thin, annular structure responsible for controlling the diameter and size of the pupil, controls the amount of light reaching the retina
Pupil
hole located in the center of the iris that allows light to strike the retina, appears black because light rays entering the pupil are absorbed
Choroid
thin, pigmented, vascular layer, between the sclera and retina, brings oxygen and nutrients to the outer retina
Ciliary Body
part of the eye that included the ciliary muscle and the ciliary epithelium
Ciliary muscle
controls the shape of the lens
Ciliary epithelium
produces aqueous humor
Lens
transparent biconvex structure that refracts light, focusing it on the retina
Accommodation Triad (Near)
- Ciliary Body Contracts (relaxed suspensory ligaments, lens balls up)
- Eyes converge
- Pupil constricts
Accommodation Triad (Far)
ciliary body relaxes, contracted suspensory ligaments, flat lens
Retina
innermost layer of light sensitive tissue, images are processed here then nerve impulses are sent to the brain
Optic Nerve
cranial nerve 2, sensory for vision, sight sensation
Anterior chamber of the eye
aqueous humor filler space inside the eye between the iris and the cornea
Interior chamber of the eye
located between the iris and lens, important for aqueous humor circulation
Aqueous humor
transparent fluid similar to plasma, fills the anterior and posterior chambers of the eye, maintains pressure, provides nutrients, and prevents dryness
Canal of Schlemm
Drains aqueous humor from the eye to the veins
Vitreous humor
clear gel that fills the space between the lens and retina, keeps eye round and clear, allows light to pass through, can protect the retina from shock
Blood supply to the Retina
Choroid and Retinal Blood Vessels
Ganglion layer
made of retinal ganglion cells and displaced amacrine cells
final output neurons of the retina that receives information from the photoreceptors
axons of retinal ganglion cells form the optic nerve fibers