ex. 23 [anatomy of visual system]

• tarsal glands: secrete oily secretion that lubricates surface of eye
• ciliary glands: oily secretion lubricating eye and lashes; infection called sty
• conjunctivae: secrete mucus to lubricate eye; infection is conjunctivitis "pink eye"
• medial and lateral commissures: corners of eye, medial has lacrimal caruncle
• lacrimal caruncle: secretes whitish oily stuff; eye boogers
• lacrimal apparatus: protects and keeps eye moist
• lacrimal gland: secrete lacrimal fluid (antibodies, mucus, lysozomes)
• lacrimal puncta: allow lacrimal fluid to drain into superior and inferior canaliculi
• lacrimal canaliculi: allow lacrimal fluid to drain into lacrimal sac
• lacrimal sac: allows lacrimal fluid to drain into nasolacrimal duct
• nasolacrimal duct: allows lacrimal fluid to flow into nasal cavity
• lateral rectus: moves eye laterally (6 abducens)
• medial rectus: moves eye medially (3 oculomotor)
• superior rectus: elevates eye and turns medially (3 oculomotor)
• inferior rectus: depresses eye and turns it medially (3 oculomotor)
• inferior oblique: elevates eye and turns laterally (3 oculomotor)
• superior oblique: depresses eye and turns laterally (4 trochlear)
• cataract: clouding of the lens of the eye, resulting in blurred vision
• glaucoma: a condition in which the pressure inside the eye is too high
• optic disc: blind spot due to lack of photoreceptors and where optic nerve exits
• macula lutea: area with high cone density with its center the fovea centralis which has only cones and is area of greatest visual activity
• aqueous humor formed by capillaries of ciliary processes to maintain intraocular pressure and give nutrients to lens and cornea
• aqueous humor drained into scleral venous sinus
• vitreous humor is the gel-like substance that fills the eyeball and helps maintain its shape, keeping retina firmly against wall of eye; formed before birth and lasts a lifetime
• light bending media: cornea, lens, aqueous humor and vitreous humor
• major neurons in neural layer

  • ganglion cells
  • bipolar cells
  • photoreceptors
• rods are specialized for dim-light and peripheral vision; gray tones
• cones are color photoreceptors w/ high visual acuity and function under bright light only
• edge of macula to retina, cone density declines gradually
• optic chiasm: fibers from medial side of each eye cross over to opposite side
• each optic tract contains fibers from lateral side of eye on same side and medial side from the opposite eye
• optic tract fibers synapse w/ neurons at lateral geniculate nucleus of thalamus
• in primary visual cortex axons synapse with cortical neurons and visual interpretation occurs
• sclera: maintains shape of eye and provides attachment point for extrinsic eye muscles
• cornea: forms clear window for eye and major light bending medium of eye
• choroid: blood vessels nourish other layers of eye, melanin absorbs excess light
• ciliary muscle: alters shape of lens
• ciliary processes: form aqueous humor by filtering plasma
• ciliary zonule: attaches lens to ciliary processes
• iris: controls amount of light entering eye by changing pupil diameter