Lab midterm Vision, Smell, and Taste Flashcards
What is the shape of the human eye?
Sphere-shaped, with only about 1/6 of the anterior surface visible.
What is the function of the lacrimal gland?
Secretes lacrimal fluid, which drains into the nasal cavity.
What is the function of the lacrimal caruncle?
Secretes oily fluid to lubricate the eye.
What is the conjunctiva and what happens when it is inflamed?
A clear mucous membrane lining the eyelids and anterior white part of the eye. Inflammation results in conjunctivitis.
What is a stye?
An infection of the ciliary gland, a sebaceous and modified sweat gland found between eyelash follicles.
How many extrinsic eye muscles does each eye have?
6 muscles: 4 rectus, 2 oblique, controlled by CN III (oculomotor), IV (trochlear), and VI (abducens).
What are the main parts of the internal eye anatomy?
Sclera, cornea, choroid, iris, pupil, lens, ciliary muscle.
What is the function of the cornea?
It is transparent, continuous with the sclera, and refracts light as it enters the eye.
What is the function of the iris?
Controls the amount of light entering the eye by adjusting pupil diameter.
What is the function of the lens?
Focuses light onto the retina and separates the anterior and posterior segments of the eye.
What is the function of aqueous humor?
Maintains intraocular pressure, provides nutrients, and is constantly draining.
What is the function of vitreous humor?
Helps keep the retina in place; does not renew.
What are rods and cones responsible for?
Rods detect dim light and grey tones; cones detect bright light, color, and provide high visual acuity.
Where is the highest concentration of cones in the eye?
In the fovea centralis, located in the macula.
What is the optic disc?
The blind spot where the optic nerve leaves the eye, containing no photoreceptors.
What is the simplified pathway of light through the eye?
Light passes through the cornea, aqueous humor, lens, vitreous humor, and then reaches the retina.
What is binocular vision?
Combining input from both eyes into a single image, aiding in depth perception.
What is glaucoma?
A condition where aqueous humor drainage is blocked, increasing intraocular pressure and potentially causing blindness.
What are cataracts?
Clouding of the lens, usually due to aging, leading to vision loss.
What is myopia?
Nearsightedness, where close objects are clear, but distant objects are blurry due to the eye being too long.
What is hyperopia?
Farsightedness, where distant objects are clear but close objects are blurry due to the eye being too short.
What is accommodation in vision?
The ability of the eye to adjust focus between near and far objects by changing the shape of the lens.
What is presbyopia?
Age-related decline in lens elasticity, making near vision more difficult.
What does the Snellen Eye Chart test?
Visual acuity (e.g., 20/30 vision means the person sees at 20 feet what a normal person sees at 30 feet).
What is astigmatism?
A vision issue caused by an irregular curvature of the lens or cornea.
What causes color blindness?
A deficiency in one or more types of cone cells, affecting the ability to perceive certain colors.
Which cranial nerves control eye muscles?
CN III (oculomotor), IV (trochlear), and VI (abducens).
What is PERLLA?
Pupils Equal, Round, Reacting to Light and Accommodation.
What type of receptors does olfaction (smell) use?
Chemoreceptors that respond to chemicals in solution.
Where is the olfactory epithelium located?
In the roof of the nasal cavity.
What type of receptors does gustation (taste) use?
Chemoreceptors that detect molecules dissolved in saliva.
Where are taste buds found?
Mostly on papillae, the peg-like projections on the tongue.
What are the five basic taste sensations?
Sweet, sour, salty, bitter, umami.
Which cranial nerves are involved in taste?
CN VII (facial) for the anterior 2/3 of the tongue, CN IX (glossopharyngeal) for the posterior 1/3.
What is the function of the tapetum lucidum in cow eyes?
A reflective layer behind the retina that helps cows see better in low light; not present in humans.
