A&P Lab Exam 1 (spring)
How is the right optic tract anatomically different from the right optic nerve?
-The right optic nerve contains fibers from the right eye only. -The right optic tract contains fibers from the lateral aspect of the right eye and the medial aspect of the left eye.
Why is it advantageous to have pain receptors that are sensitive to all vigorous stimuli, whether heat, cold, or pressure?
Because each could cause tissue damage in excessive exposure, warning that something is wrong.
What is the advantage of binocular vision?
Binocular vision provides 3-D vision and depth perception.
What is a sty?
Inflammation of a small oil or sweat gland associated with the eye exterior.
How can you explain the fact that we see a great range of colors even though only three cone types exist?
Other colors are formed by the overlapping of 3 primary cones; color combos are blue, green, and red
Explain why vision is lost when light hits the blind spot.
The area lacks photoreceptors
What does the retina look like?
Thin yellowish white or tan membrane that often becomes crumpled during dissection of the eye
Why do you often have to blow your nose after crying?
This is because tears drain into the nasal cavity via the nasolacrimal duct.
What is the function of adipose tissue?
To package, protect, and cushion the eyeball in the bony orbit.
Exteroceptor
a sensory receptor which receives external stimuli.
Interoceptors
a sensory receptor which receives stimuli from within the body, especially from the gut and other internal organs.
Accommodation
ability to focus for close (less than 20 ft) vision
Tarsal glands produce
an oily secretion that lubricates the eye
Cornea
anterior continuation of the sclera - your "window on the world"
Fovea centralis
area of critical focusing and detailed color vision
filaments of the olfactory nerve
axons that pass through the cribriform foramina
olfactory sensory neurons
bipolar neurons with nonmotile cilia
Astigmatism
blurred vision due to unequal curvatures of the lens or cornea
olfactory stem cells
cell type that differentiates to replace olfactory sensory neurons
supporting cells
cell type that forms most of the olfactory epithelium
Sclera
composed of tough, white, opaque, fibrous connective tissue
Bright light/color receptors
cones
Define adaptation of sensory receptors
decline in receptor sensitivity and stimulation with prolonged unchanging stimuli
lamellar corpuscle
deep pressure receptor located in the dermis
Superior oblique turns the eye
down and laterally
Inferior rectus turns the eye
down and medially
Scleral venous sinus
drains the aqueous humor from the eye
Hyperopia
farsightedness
Aqueous humor
fluid filling the anterior segment of the eye
Ciliary process of ciliary body
form the aqueous humor
Choroid
forms the bulk of the heavily pigmented vascular layer
conjunctivis
inflammation of the conjunctiva
Lateral rectus turns the eye
laterally
Retina
layer containing the rods and cones
Refraction
light bending
cornea, aqueous humor, lens, vitreous humor are
light-bending media of the eye
Medial Rectus turns the eye
medially
Ciliary body
modification of the choroid that contains the ciliary muscle
Conjunctiva produces
mucus
Myopia
nearsightedness
Emmetropia
normal vision
free nerve ending
pain receptor
Which cutaneous receptors are the most numerous?
pain receptors
Optic disc
part of the retina that lacks photoreceptors
The visual pathway to the occipital lobe
photoreceptors -> bipolar cells -> ganglion cell -> neuron -> cortical neuron
Pathway of sound through the ear
pinna-> auditory canal-> eardrum-> ossicles-> vestibule-> cochlea-> cochlear nerve-> brain
muscle spindle
proprioceptor located in skeletal muscle
What is the function of tapetum lucidum?
reflects light increasing light stimulation of the retina under dim light conditions
Dim light receptors
rods
Ciliary body & Iris are composed of
smooth muscle structures
Vitreous humor
substance occupying the posterior segment of the eyeball
Ciliary glands produce
sweat
What modification of the choroid that is not present in humans is found in the cow eye?
tapetum lucidum
lacrimal glands produce
tears
olfactory epithelium
the organ of smell
Receptive field
the particular region of the sensory space in which a stimulus will modify the firing of a neuron
epithelial tactile complex
touch receptor located in the deepest layer of the epidermis
tactile corpuscle
touch receptor located in the dermal papillae
Inferior oblique turns the eye
up and laterally
Superior rectus turns the eye
up and medially
Sclera
white of the eye
Caruncle produces
whitish oily secretion