LearnSmart CH16
Which events occur during bright light adaptation?
- Rods become inactive - Pupils constrict - Cones gradually adjust
Which are true of rods?
- There are more than 100 million rod cells per eye - They function well in dim light
Match these terms with their definitions.
Emmetropia - normal vision Hyperopia - farsightedness Myopia - nearsightedness
Which may result in symptoms such as reduced field of vision, dim vision and/or halos around lights?
Glaucoma
Which are the basic taste sensations?
Sweet, umami, sour
Prior to being stimulated by light the retinal portion of rhodopsin is in a bent twisted shape called _ -retinal
cis
As we adjust to low light, our _ become nonfunctional and it may take _ for rhodopsin to become regenerated sufficiently so that you can see well in low-light conditions.
cones, 20-30 minutes
The primary function of the _ is to prevent large objects from contacting the eye.
eyelashes
When the bipolar cells release their neurotransmitter, the _ cells propagate a nerve signal along the _ nerve.
ganglion, optic
As a consequence of the dark current, _ channels in the photoreceptor open.
glutamate
In the taste bud, the basal cells replace the _ cells.
gustatory
The nasolacrimal duct is found on the _ side of the nose.
lateral
Lacrimal fluid prevents bacterial infection because it contains an antibacterial enzyme called _.
lysozyme
The sphincter pupillae is controlled by the _ division of the nervous system.
parasympathetic
What is the space behind the lens called?
posterior cavity
The apparent distortion of the spoon in the water glass is due to the phenomenon called _.
refraction
Tarsal glands are _.
sebaceous glands
The ciliary muscles are made of _ muscle.
smooth
The dendritic ending of each gustatory cell is formed by a slender gustatory microvillus, also called a _.
taste hair
Which are true of conjunctiva?
- it is vascular - it does not cover the cornea - it contains goblet cells
Place the structure of the eye in order from superficial to deep. Start with the outermost structure first.
1. Choroid 2. Photoreceptors 3. Horizontal cells 4. Bipolar cells
Place the layers of the eye in order from superficial to deep.
1. Fibrous tunic 2. Vascular tunic 3. Retina
Place the structures of the vascular tunic in order from anterior to posterior.
1. Iris 2. Ciliary body 3. Choroid
Order these structures from superficial to deep. Outermost structure first.
1. Sclera 2. Choroid 3. Pigmented layer of retina 4. Neural layer of retina
Which are characteristics of the cornea?
Avascular, Transparent
Which type of receptor detects color?
B
Gustatory information travels through which cranial nerves?
CN IX and CN VII
What structure is filled with pigment from melanocytes?
Choroid
What is the name of the "snail-shaped" structure of the inner ear?
Cochlea
What structure focuses incoming light onto the retina?
Lens
What is the margin between the photosensitive and nonphotosensitive regions of the retina called?
Ora Serrata
The portion of the conjunctiva on the inside of the eyelid is called the _.
Palpebral Conjunctiva
What structure is the "white" of the eye?
Sclera
What structure makes up the posterior 5/6 of the fibrous tunic?
Sclera
The process is called the bleaching reaction because rhodopsin goes from a _ color to _.
bluish-purple, colorless
Macular degeneration occurs when the _ degenerates.
macula lutea
The lacrimal caruncle is on the _ side of the eye.
medial
Accommodation is the process of making the lens _.
more spherical
A detached retina is more likely to occur if a person is _.
nearsighted
Ganglion axons of the retina converge to form the _ nerve.
optic
The fat surrounding the eye is called _ fat.
orbital
The process by which photoreceptors become activated when the photopigments are altered by light entering the eye is _ .
phototransduction
Each type of photoreceptor has both an outer segment that extend into the _ layer of the retina and an inner segment.
pigmented
Aqueous humor is secreted into the _ chamber before traveling to the _ chamber of the eye.
posterior, anterior
An aging person would need to start wearing reading glasses if they suffer from _.
presbyopia
As tears drain, through the lacrimal caruncle, they enter small holes called the lacrimal _.
puncta
The black hole in the eye is called the _ and it is surrounded by the colorful _.
pupil; iris
In the eye, the _ humor is gelatinous.
vitreous
What color is the macula lutea?
yellow
Refraction of light for vision is greatest as light rays pass from _ into the _ because the difference in their refractive index is maximal.
air, cornea
What chamber is between the iris and cornea?
anterior chamber
Both the anterior and posterior chambers of the anterior cavity contain _ humor.
aqueous
What disorder is caused by unequal curvatures of the lens and cornea?
astigmatism
The _ controls the size or diameter of the pupil and thus the amount of light entering the eye.
iris
The parasympathetic nervous system controls _.
A
Taste buds are made of gustatory cells, supporting cells, and _ cells.
basal
In the light, _ cells are no longer inhibited and therefore release the neurotransmitter glutamate.
bipolar
Where are tears created?
Lacrimal Apparatus
True/False: In cones, the bleaching reaction occurs as cis-retinal transforms to trans-retinal.
True
Where is the trans-retinal transported so that the retinal can be reconverted back to its cis formation?
pigment epithelium
The lens is _ when we are viewing close-up objects.
rounded
Pink eye is also called _.
conjunctivitis
A _ shaped lens is used to treat hyperopia and a _ shaped lens is used to treat myopia.
convex, concave
The optic disc is associated with _.
cranial nerve II
Photoreceptors are _ when it is completely dark.
depolarized
Rods are essentially nonfunctional in bright light because _.
in bright light, rhodopsin will bleach as fast as it is reformed.
The _ segment of the photoreceptors connect directly to the cell body.
inner
Gustatory sensations travel to the _ of the brain.
insula
Cataracts are a disorder of the _.
lens
