Histology-Eye Flashcards
3 layers of the eye
1) Fibrous (cornea & sclera) 2) Uvea (iris, ciliary body, choroid) 3) Retina
Main refractive structure of they eye
Cornea
White of the eye continuous with the dura matter that covers the optic nerve
Sclera
Contains smooth muscle that adjusts the size of the pupil
Iris
Contains smooth muscle that adjusts the size of the lens
Ciliary body
Vasculature that nourishes the outer layers of the retina
Choroid
3 chambers of the eye
1) Anterior (aqueous humor) 2) Posterior (aqueous humor) 3) Vitreous (vitreous humor)
Identify the labeled structures of the eye:
1) Sclera 2) Ciliary body 3) Optic Nerve 4) Vitreous chamber 5) Lens 6) Posterior chamber 7) Iris 8) Anterior chamber 9) Cornea
Identify the labels structures of the eye:
1) Cornea 2) Eyelid 3) Palpebral Conjunctiva 4) Fornix 5) Ciliary body 6) Bulbar Conjunctiva 7) Ciliary process 8) Lens 9) Iris 10) Anterior chamber 11) Vitreous space *Note how the bulbar conjunctiva makes a u-turn at the fornix to become to palpebral conjunctiva
In what structure at the ciliary muscles contained?
Ciliary body
What connects the ciliary body to the lens?
Zonular fibers from the suspensory ligament of the lens connect to the ciliary process.
What are the different layers of the cornea?
1) Corneal epithelium 2) Corneal stroma 3) Corneal endothelium
Corneal epithelium sensory innervation
V1 (opthalmic nerve)
Part of cornea that is only collagen
Stroma. It is also avascular so you can see through it
Damage to this layer of the cornea causes swelling and opacities in the cornea.
Corneal endothelium
Most quickly regenerating part of the cornea.
Corneal epithelium
Identify the labeled structures below:
1) Bulbar conjunctiva 2) Sclera 3) Ciliary Muscle 4) Ciliary Process 5) Zonular Fibers 6) Iris
Ciliary muscle innervation
CN III parasympathetic (ciliary ganglion)
What do the zonular fibers do when you are reading a text?
They relax to make the lens more round. This increases the refractive power of the lens for near sight.
What is the function of the structures indicated below?
1) Iris. The stroma contains fibroblasts and melanocytes that determine eye color. 2) Sphincter pupillae. These are innervated by the ciliary ganglion (CN III) and contract to constrict the pupil. Note that the lens is below the iris with a protective capsule and epithelial layer.
Identify the structures indicated below:
1) Canal of Schlemm 2) Trabecular Meshwork 3) Iris 4) Dilator Pupillae 5) Ciliary Processes
What is the region called where the cornea meets the sclera?
Limbus
What regions of the eye may have a pathology in patients with glaucoma?
Aqueous humor is secreted by the ciliary processes into the posterior chamber, it then enters the anterior chamber via the pupil, it then percolates through the trabecular meshwork and exits via the canal of Schlemm. Blockage anywhere along this pathway can cause glaucoma.
What muscles are responsible for changing the pupil during sympathetic stimulation?
Dilator pupillae. They are innervated by the superior cervical ganglion.
What are the different structures indicated below?
The image is that of ciliary processes. 1) Inner non-pigmented layer continuous with the neural retina. 2) Pigmented outer layer continuous with the pigmented retinal epithelium.
Clouding of the lens
Cataract
Where are the oldest cells found in the lens?
At the center. The outer layer is an epithelial layer. Th internal layer is differentiated fiber cells that move internally as they age.
What is the function of each retinal layer indicated below?
1) Photopigment of rods & cones (light-sensitive) 2) Nuclei of rods and cones 3) Axons of rods & cones headed towards dendrites of bipolar cells 4) Bipolar cells 5) Axons of bipolar cells headed toward dendrites of ganglion cells 6) Ganglion cells 7) Axons of ganglion cells that course to the optic disc to form CN II
In what region of the retina is this image not from?
Fovea. In the fovea there are only cones. In this image, there are both rods and cones.
Where does the central artery of the retina enter the eyeball?
Through the optic disc. Note that there are no photoreceptors here and this is the blind spot of the eye.
What is the function of each structure indicated below?
1) Skin: protects eye 2) Orbicularis Oculi Muscle: blinks eye, innervated by CN VII 3) Meibomian (tarsal) glands: lubricate sclera, when inflamed = chalazion and stye 4) Palpebral conjunctiva: glide on eye, when inflamed = conjunctivitis
Which photoreceptor is most sensitive to light? To color?
Light = rods. Color = cones.
