Vision Flashcards
Structure, Lacrimal Appartus (19 cards)
Describe the sense of touch and its mediators.
The sense of touch is one of the general senses, mediated by general receptors.
List the special senses of the body.
The special senses include vision, chemical senses (taste and smell), hearing, and equilibrium.
Explain the difference between general receptors and special sensory receptors.
General receptors are modified nerves, while special sensory receptors are distinct receptor cells localized in the head region.
What are the accessory structures of the eye and their functions?
Accessory structures protect the eye and aid in its function, including eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles.
Define conjunctiva and its types.
Conjunctiva is a transparent mucous membrane that produces lubricating secretion. It has two types: palpebral conjunctiva (lining underside of eyelids) and bulbar conjunctiva (covering the white of the eyes, not the cornea).
How does the conjunctival sac function in relation to contact lenses?
The conjunctival sac is the space between the palpebral and bulbar conjunctiva, where contact lenses rest.
Explain the role of the lacrimal apparatus in eye function.
The lacrimal apparatus is responsible for the production and drainage of tears, which help to lubricate and protect the eye.
Describe the process of phototransduction in the retina.
Phototransduction is the process by which light is converted into electrical signals in the retina, allowing for visual information processing.
Outline the visual pathway to the brain.
The visual pathway involves the transmission of visual information from the retina through the optic nerve to various brain regions for processing.
Describe the function of the lacrimal gland.
The lacrimal gland produces and secretes tears, also known as lacrimal secretions.
Explain how tears enter the conjunctival sac.
Tears enter the conjunctival sac via the excretory ducts of the lacrimal gland.
How do tears flow across the eyeball?
Tears flow down and across the eyeball.
Define the lacrimal puncta.
Lacrimal puncta are openings where tears enter the lacrimal canaliculi.
What happens to tears after they enter the lacrimal canaliculi?
After entering the lacrimal canaliculi, tears drain into the lacrimal sac.
Describe the pathway of tears from the lacrimal sac to the nasal cavity.
From the lacrimal sac, tears empty via the nasolacrimal duct into the inferior meatus of the nasal cavity.
Explain the role of extrinsic eye muscles.
Extrinsic eye muscles enable the eye to follow moving objects, maintain the shape of the eyeball, and hold it in orbit.
What are the three layers of the wall of the eyeball?
The wall of the eyeball contains three layers: the fibrous layer, the vascular layer, and the inner layer.
Define the internal cavity of the eyeball.
The internal cavity of the eyeball is filled with fluids called humors.
How does the lens affect the internal cavity of the eyeball?
The lens separates the internal cavity into anterior and posterior segments.
