Eyes
optic disc (blind spot)
*site where optic nerve leaves the eye *lacks photoreceptors
Blind spot
An area toward the back of the retina that doesn't register incoming light rays
Lysozyme
An enzyme in tears that inhibits the growth of bacteria on the front of the eyeball
Cornea
Anteriormost clear part of fibrous tunic
Sclera
Fibrous tunic, white and opaque
aqueous humor
Fluid that fills the anterior segment of the eye, provides nutrients to the lens and cornea
Optic nerve
Formed by ganglion neurons, transmits impulses from the retina to the brain
Anterior cavity of eye
Further broken into anterior chamber-fro cornea to iris and posterior chamber-fro iris to ciliary body
vitreous humor
Gel-like substance, filling the posterior segment of the eyeball, helps reinforce the eyeball
vitreous humor
Helps support lens Rolds retina in place Contributes to intraoculsr pressure
Conjunctiva
Thin transparent mucous membrane covering the inner surfaces of the eyelids and outer surface of eyes
Lens
This structure aids in focusing light rays on the retina
Retina
Tunic concerned w image formation
Retina kept in place by the
Vitreous humor
Lacriminal glands
Within the orbits, secretes tears
Iris
a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening, has two layers of smooth muscle fibers
macula lutea
a yellowish central area of the retina that is rich in cones and that mediates clear detailed vision
The lens and cornea have no capillaries and are nourished by
aqueous humor
fovea centralis
area of acute or discriminatory vision
Optic disk
area of retina that lacks photoreceptors
anterior cavity of eye
between cornea and lens, filled with aqueous humor
anterior cavity of eye
between cornea and lens, filled with aqueous humor -helps maintain intraocular pressure n imp route for nutrients n waste transport, blackage in circulation o aqueous humor results in glaucoma
posterior chamber of eye
between iris and lens or ciliary body
Posterior cavity
filled with vitreous humor
lacriminal apparatus
group of structures involved in producing and draining tears
Choroid coat
heavily pigmented tunic that prevents light scattering within the eye
Fibrous tunic
provides support/protection, serves as attachment surface for extra-ocular muscles, and has structures to assist in focusing
Muscle that moves eyeball
rectus muscle
Aqueous humor, cornea, lens, vitreous humor
refractory media of the eye
Iris
regulates the size of the pupil
Nervous tunic
retina
Fibrous tunic
sclera and cornea
suspensory ligaments
secures the lens to the ciliary body
Pigmented retina
single layer of cells; filled with melanin. With choroid, enhances visual acuity by isolating individual photoreceptors, reducing light scattering -keeps lite fro being reflected back into eyes
Canal of Schlemm
small veins that reabsorb aqueous humor
Ciliary body and iris
smooth muscle structures (sites of intrinsic eye muscles)
anterior chamber of eye
space between cornea and iris
nasolacrimal duct
takes tears to the nasal cavity
Sclera
the firm white fibrous outer layer of the eyeball; protects and maintains eyeball shape -made of collagen and elastic fibers -thick in back and thin at front -vessels and nerves penetrate to reach organs
vitreous chamber
the main interior portion of the eye, filled with vitreous humor
Cornea
the transparent layer forming the front of the eye. -beneath epithelium is dense matrix made of collagen fibers -no bld vessels, receives oxygen n nutrients fro tears -most sensitive part of eye, lots of nerve endings -damage can cause blindness
Fovea centralis
tiny pit or depression in the retina that is the region of clearest vision -area of greatest visual activity, contains only cone cells
Sclera
white hard part of the eye
Choroid layer
Contains a dark blue pigment to absorb light and prevent glare within the eyeball
Choroid
Contains extensive capillary network delivering oxygen n nutrition to retina, n contains scattered melanocytes
Rods
Contains rhodopsin and detect the presence of light
Myopia
Corrected with concave lens
The white outer tough cn tissue covering of the eyeball
Sclera
Blockage of the whi is suspected in glaucoma?
Scleral venous sinus
aqueous humor
The liquid that fills the anterior section of the eyeball, giving it shape
Choroid
The middle layer of eyeball which contains a black pigment and prevents extraneous light from "reflecting around" inside the eye
Cornea
The transparent part of the sclera layer, it is located on the front surface of the eyeball and aids in focusing light rays as they enter the eye
Cornea
The transparent part of the sclera that reflects light
Hyperopia
A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects -- called also farsightedness, coreccting possible w convex lens
vitrous body
A gel-like material that fills the posterior section of the eyeball, giving it shape
Conjunctiva
A thin membrane that lines the eyelids and covers the whites of the eyes
conjunctiva
A thin mucous membrane layer that provides lubrication and covers the cornea and posterior surfaces of the eyelids
Fovea
A very small area on the retina of sharpest focus of incoming light rays
Iris
Colored part of the eyewhich regulated the amount of light entering the eye
Canal of Schlemm
Drains the aqueous humor of the eye
Optic nerve
Exiting at the back of the eye, this structure carries nerve impulses for vision in the brain
Trace the pathway that the secretion of the lacriminal glands takes from the surface of the eye by designing a number to each structure
Lacriminal glands Lacriminal sac Nasolacriminal duct Nasal cavity
Number the proper sequence inolved in process of vision
Light rays➡ Cornea Aqueous humor Lens Vitreous humor Retina Optic nerve
vascular tissue
Middle layer of eye
Extrinsic muscles
Move the eyeball side to side or up and down
Iris
Pigmented "diaphragm" of the eye
Cones
Receptors that detect color
Receptors for vision located in whi pt of eye?
Retina
Rods
Retinal nerve cells sensitive to low levels of light intensity but not to color
Cones
Retinal nerve cells used for color vision
Optic disc
The area of the retina where the optic nerve passes through; no rods or cones are present
Pupil
The hole through which light enters the eye
Retina
The inner layer of the eyeball that's made of light sensitive nerve cells called rods and cones
Retina
The layer of the eyeball which contains visual receptors
Lens
The only adjustable part of the light retracting system
Sclera
The outer layer of the eyeball that provides protection
Fovea
The part of the retina that contains only cones
suspensory ligaments
The structures that hold the lens of the eye in place
Vascular coat of eyeball, deeply pigmented
choroid
Vascular tunic
choroid, ciliary body, iris, pupil
Muscle responsible for altering shape of lens
ciliary muscle
lacriminal apparatus
consists of the lacrimal gland and a series of ducts that drain the tears into the nasal cavity
Eyelids
contain skeletal muscle; spread tears across the front of the eyeball
Vascular tunic
contains most of the blood vessels of the eye and intrinsic eye muscles -provide route for bld vessels regulatin amt o lite entering eye, secretin n absorbin Aquarius humor n controllin shape o lens
Posterior cavity
contains vitreous humor
ciliary body
contracts to change the shape of the lens
Nervous tunic
inner retinal layer made of nervous tissue
Bacterial growth on the front of the eyeball is inhibited by
lysozyme in tears
Ciliary body
muscular structure that manipulates the lens
Choroid coat
nutritive (vascular) tunic of the eye
Fibrous tunic
outer layer of the eye made of cn tissue
