WGU D312 EXAM OBJECTIVE ASSESSMENT | QUESTIONS AND
ANSWERS | VERIFIED ANSWERS | LATEST EXAM
olfactory transduction
conversion of chemical molecules in the air into neural impulses by the
olfactory cilia
local depolarization
a locally generated depolarization that causes an action potential
adaptation
the olfactory epithelium's sensitivity to smells over time
odor threshold
lowest concentration of a certain odor compound that is perceivable by the
human sense of smell
In addition to tunicae, each eye consists of...
optical and neural structures.
tunicae
Layers of the eye; there are 3
What are the 3 layers constructing the wall of the eye?
fibrous, vascular, and neural layer
fibrous tunica
fibrous, outer coat
vascular tunica
pigmented, vascular coat
What is the purpose of the blood and lymphatic vessels of the Choroid?
drain excess fluid from the posterior cavity
ciliary arteries
Arterial supply to the choroid
,Ciliary body
the anterior portion of the choroid that sits behind the Iris, forming a ring
around the Lens.
The Ciliary body is composed of...
smooth muscle
Suspensory ligaments project from the ciliary body and attach it to
the lens
Functions of the Ciliary Body.
1) support the iris and lens,
2) adjust curvature of the lens
3) secrete aqueous humor into the posterior chamber
The iris contains two rings of muscles
the pupillary constrictor muscles and the pupillary dilator muscles.
Function of the Iris
Change diameter of the aperture of the pupil
The lens
a curved structure in the eye that bends and focuses lightfor the retina to see
images clearly
Neural Tunica
the innermost, neural layer.
The retina is attached to...
the optic disc and the ora serrata
the Retina contains...
photoreceptors and associated neurons and fibers.
macula lutea
the area of the retina that provides the clearest vision; contains only cone
photoreceptors
fovea centralis
the area of the retina where vision is most accurate.
,optic disc or blind spot
the point from which ganglion cells from the retina leave the back of the eye to
form the optic nerve; no photoreceptors
Optic Nerve (Cranial Nerve II)
Nerve that carries impulses for sense of sight.
optic chiasm
where optic nerves cross
optical structures
Admit and refract light and focus images
-cornea
-pupil
-lens
-aqueous humor( anterior cavity b/w cornea + lens)
- vitreous humor (posterior cavity b/w lens+ retina)
Aqueous humor
clear, watery fluid that is filtered from blood capillaries in the ciliary body and
is constantly secreted
Function of Aqueous Humor
maintain intraocular pressure
drain via the scleral venous sinus, located at the junction of the cornea and
sclera
provide nutrients to the avascular cornea and sclera.
suspensory ligaments
hold the lens in place
can change shape to accommodate viewing objects at closer or further
distances
The Lens
The vitreous body consists of...
is formed during the...
transparent jelly that fills the posterior cavity
development of the eye
, It is not renewed or replaced during life
The vitreous body
The posterior chamber is located between the
the iris, lens, suspensory ligaments, and the ciliary body
It is filled with aqueous humor and allows light to pass through it
The posterior chamber
The anterior chamber is located between the...
and is filled with... that allows light to pass through
cornea and iris
aqueous humor
neural structures of the eye
retina and optic nerve
process light signals and relay them to the brain
retina
the inner lining of the posterior eye; consists of 10 layers of neural, epithelial,
and supporting cells.
two types of photoreceptor cells
rods and cones
Photoreceptors
specialized receptors that convert optical images into neural signals that the
brain interprets
Rod cells
photorecptors sensitive to low light and provide black and white vision d/t the
photopigment they contain
Cone cells
sensitive to high light levels and provide color vision
Rhodopsin
the photopigment present in rod cells
Photopsin
ANSWERS | VERIFIED ANSWERS | LATEST EXAM
olfactory transduction
conversion of chemical molecules in the air into neural impulses by the
olfactory cilia
local depolarization
a locally generated depolarization that causes an action potential
adaptation
the olfactory epithelium's sensitivity to smells over time
odor threshold
lowest concentration of a certain odor compound that is perceivable by the
human sense of smell
In addition to tunicae, each eye consists of...
optical and neural structures.
tunicae
Layers of the eye; there are 3
What are the 3 layers constructing the wall of the eye?
fibrous, vascular, and neural layer
fibrous tunica
fibrous, outer coat
vascular tunica
pigmented, vascular coat
What is the purpose of the blood and lymphatic vessels of the Choroid?
drain excess fluid from the posterior cavity
ciliary arteries
Arterial supply to the choroid
,Ciliary body
the anterior portion of the choroid that sits behind the Iris, forming a ring
around the Lens.
The Ciliary body is composed of...
smooth muscle
Suspensory ligaments project from the ciliary body and attach it to
the lens
Functions of the Ciliary Body.
1) support the iris and lens,
2) adjust curvature of the lens
3) secrete aqueous humor into the posterior chamber
The iris contains two rings of muscles
the pupillary constrictor muscles and the pupillary dilator muscles.
Function of the Iris
Change diameter of the aperture of the pupil
The lens
a curved structure in the eye that bends and focuses lightfor the retina to see
images clearly
Neural Tunica
the innermost, neural layer.
The retina is attached to...
the optic disc and the ora serrata
the Retina contains...
photoreceptors and associated neurons and fibers.
macula lutea
the area of the retina that provides the clearest vision; contains only cone
photoreceptors
fovea centralis
the area of the retina where vision is most accurate.
,optic disc or blind spot
the point from which ganglion cells from the retina leave the back of the eye to
form the optic nerve; no photoreceptors
Optic Nerve (Cranial Nerve II)
Nerve that carries impulses for sense of sight.
optic chiasm
where optic nerves cross
optical structures
Admit and refract light and focus images
-cornea
-pupil
-lens
-aqueous humor( anterior cavity b/w cornea + lens)
- vitreous humor (posterior cavity b/w lens+ retina)
Aqueous humor
clear, watery fluid that is filtered from blood capillaries in the ciliary body and
is constantly secreted
Function of Aqueous Humor
maintain intraocular pressure
drain via the scleral venous sinus, located at the junction of the cornea and
sclera
provide nutrients to the avascular cornea and sclera.
suspensory ligaments
hold the lens in place
can change shape to accommodate viewing objects at closer or further
distances
The Lens
The vitreous body consists of...
is formed during the...
transparent jelly that fills the posterior cavity
development of the eye
, It is not renewed or replaced during life
The vitreous body
The posterior chamber is located between the
the iris, lens, suspensory ligaments, and the ciliary body
It is filled with aqueous humor and allows light to pass through it
The posterior chamber
The anterior chamber is located between the...
and is filled with... that allows light to pass through
cornea and iris
aqueous humor
neural structures of the eye
retina and optic nerve
process light signals and relay them to the brain
retina
the inner lining of the posterior eye; consists of 10 layers of neural, epithelial,
and supporting cells.
two types of photoreceptor cells
rods and cones
Photoreceptors
specialized receptors that convert optical images into neural signals that the
brain interprets
Rod cells
photorecptors sensitive to low light and provide black and white vision d/t the
photopigment they contain
Cone cells
sensitive to high light levels and provide color vision
Rhodopsin
the photopigment present in rod cells
Photopsin
