Special Sense Flashcards
____________________: the space between upper and lower eyelids
Palpebral fissure
____________________: the medial and lateral corners of your eyes
Commissures
____________________: red lump that is a gland in the medial commissure
Caruncle
____________________: what makes the eyelid firm
Tarsal plate
____________________: mucus Membranes lining the eyelids
Conjunctiva
____________________: eyelid gland making and oily substance so ghat you eyelids doing stick
Meibomian gland
____________________: eyelids
Palpebrae
____________________: oil gland for your eyelashes (Celia)
Sebaceous ciliary gland
____________________: makes tears and is located superior and lateral to the eyeball
The lacrimal gland
What are the strictures of the lacrimal apparatus?
Lacrimal gland which produces tears
Lacrimal puncta: medial edge of eyelids
Lacrimal canal: medial edge
Nasolacrimal duct: nose
What are the functions of tears?
Moisturize, clean, and keep MO limited
What are the two kinds of photoreceptors and what is their location?
Rods and cones are found on the retina
Rods are peripheral
Cones are central
____________________: the bending of light rays to converge onto a single point in vision
Refraction
____________________: a single point where light rays converge
Focal point (on retina)
____________: a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor
Ciliary body
Hanging from the ciliary body are __________ ___________ attached to the retina so that the lends can be changed in shape
Suspensory ligaments
A straighter lense bends light less or more?
Less
Describe how images are focused
The light rays are refracted by the cornea and then lens. Suspensory ligaments of the ciliary body help the lens change shape.
______________________: perfect 20/20 vision
Emmetropia
______________________: is the ability to change the shape of your lens from fair vision (straight) to close vision (curved)
Accommodation
______________________: is the closest point you can still focus
The near point of vision
______________________: wanting to look and something, and looking at it
Voluntary fixation
______________________: allows you to keep a selected object in your visual field once it has been found unconsciously
Involuntary fixation
Describe the controls over eye movement and the part of the cerebral cortex involved
Our frontal lobe controls voluntary fixation. When the image is in our FOV our occipital lobe employs involuntary fixation to help keep the image in focus
What is Binocular Vision and what does it produce?
When 2 slightly different fov come together and produce one 3d image
______________: if your eyes are not fixating in a coordinated fashion (like when drunk) and the corresponding image does not land on the fovea centralis leading to DOUBLE VISION
Diplopia
___________________: when your eyes point in different directions and with time your fix images with one eye and the other becomes functionally blind
Strabismus
__________________: photopigment in rods requiring vitamin A for synthesis
Rhodopsin
How do photoreceptors function?
Light stimulus turned into depolarization response. Rods respond to more gray/black/white and cones to bright colors.
Which is more plentiful; rods or cones?
Rods
Which are peripheral; rods or cones?
Rods
Which see more colors; rods or cones?
Cones
Which do not show convergence so that each has its own “line” to the brain; rods or cones?
Cones
Which have precise and clear images; rods or cones?
Cones
Which help the most in night vision; rods or cones?
Rods
Why is your fovea centralis the most accurate vision?
Because it has numerous CONES which produce clear images
Rods need vitamin A for their synthesis. T or F?
T
Describe the neural components of the retina and explain lateral inhibition
Rods and cones synapse with bipolar neurons which synapse with ganglion cells (= optic nerve)
____________: neuron in the retina that acts as an interneuron between bipolar and ganglion cells. receive signals from bipolar cells and are involved in the regulation and integration of activity in bipolar and ganglion cells.
Amacrine cells
_______________: laterally interconnecting neurons having cell bodies in the inner nuclear layer of the retina of vertebrate eyes. They help integrate and regulate the input from multiple photoreceptor cells.
Horizontal cells
____________: that neighboring neurons in brain pathways have on each other. For example, in the visual system, neighboring pathways from the receptors to the optic nerve, which carries information to the visual areas of the brain can show this
Lateral inhibition
_____________: horizontal and amacrine cells reach between pathways and can inhibit weakly stimulated pathways
Lateral inhibition
__________: accuracy to distinguish detail and is measured by a Snellen eye chart
Visual acuity
__________: the ability to tell that two closely spaced points are indeed 2
Visual resolving power
In a visual acuity your number is first. T or F?
T
Describe the direct and indirect pupillary reflexes
Direct= ipsilateral: when you shine a light the pupil constricts Indirect= lateral: when you sine a light in one eye the pupils on both sides constrict (indirect reflex)
List 3 parts of the external ear
Pinna= elastic cartilage
Ear canal= EAM
Ear drum= TM
Ceruminous glands
Ear wax glands found in the ear canal
__________: the auditory tube the connects the middle ear with the throat which allows pressure to release
Eustachian tube
Parts of the middle ear
Eustachian tube
3 ossicles: malleus, incus, and stapes
__________: helps amplify sounds, touches the TM, located in the middle ear
Malleus
List the ossicles of the middle ear from outer to inner
Melleus, incus, and stapes
__________: helps amplify sounds, touches the oval window, located in middle ear
Stapes
__________: connection between the middle and inner ear, can bulge in either direction to help with pressure stabilization in the inner ear
Round window
__________: has a pattern of having and osseous (bone) labyrinth lined by a membranous labyrinth
Inner ear
In the inner ear the osseous labyrinth contains ______ fluid and the membranous labyrinth contains ________ fluid
Perilymph
Endolymph
_________ fluid of the ear has a similar ionic composition as extracellular fluid found elsewhere in the body and fills the scalae tympani and vestibuli. _________ fluid of the ear, found inside the cochlear duct (scala media), has a unique composition not found elsewhere in the body.
Perilymph
Endolymph
_____________: central part of the bony labyrinth in the inner ear, and is situated medial to the eardrum (tympanic cavity), behind the cochlea, and in front of the three semicircular canals.
Vestibule
_____________: is bony and lined by membranous utricle and saccule that function in equilibrium
Utricle
__________: an irregular, dilated sac lying in the upper and posterior part of the vestibule. It serves as the base for the three semicircular ducts. contains a sensory epithelium - the macula, which is composed of hair cells and associated supporting cells.
The utricle
___________: a bed of sensory cells in the inner ear. It translates head movements into neural impulses for the brain to interpret.
Saccule
The 3 semicircular canals are placed at 90 degrees from each other and are bony. T or F?
T
____________: tiny, fluid-filled tubes in your inner ear that help you keep your balance. When your head moves around, the liquid inside sloshes around and moves the tiny hairs that line each canal. lined with semi circular ducts and have a widened portion called the ampulla
Semicircular canals
__________: last bony portion of the ear, shaped like a snail shell, houses the receptors for hearing within the temporal bone
Cochlea
Cochlear duct
Lines the cochlea and houses hearing receptors
Describe the mechanism of hearing
1 Sounds waves are collected from the pinna
2 travel down the EAM to then
3 vibrate the TM which then
4 vibrates the ossicles which magnify the sounds wave
5 The last ossicle (stapes) pushes against the oval window making the perilymph in the scala vastibuli
6 then makes the perilymph in the lower channel (scala tympani) move as well
7 Causes the endolymph in the cochlear duct to move at the same frequency
8 stimulating the organ or corti which sits on the floor of the cochlear duct
9 tiny hairs are stimulated according to frequency
Where are the tiny hairs responsible for hearing located?
On the organ or corti on the floor of the cochear duct
The hairs nearest the apex of the Organ of Corti are (long/short?) and stimulated by (low/high?) frequency
Long and low near apex
Short and high near the base
_____________: a reflex to protects from loss of hearing stops the wild vibrating of the ossicles
Tympanic reflex or sound attenuation
Describe how to determine the location, loudness, and pitch of sound.
Location: disparity between two ears
Loudness: amplitude of sound waves
Pitch: frequency of the sound waves
Describe the mechanism for linear acceleration and decceleration
OTOLITHS move as you accelerate/decelerate thus bending hair cells leading to a nerve impulse
Describe how we detect head position
Otolith movement
In mammals, _____________ are small particles, composed of a combination of a gelatinous matrix and calcium carbonate in the viscous fluid of the saccule and utricle. The inertia of these small particles causes them to stimulate hair cells when the head moves.
Otoliths
Describe the mechanism for detecting rotational acceleration or deceleration
As you spin the hair cells (crista) in the ampulla of the semicircular ducts are stimulated leading to a nerve impulse
____________: a characteristic of eyeball movement to try and fix on an object while you spin. Spin to the R you fix L
Vestibular nystagmus
Describe the mechanism for maintaining a whole body dynamic equilibrium
Semi circular canals are all located 90 degrees from each other providing information about your equilibrium. This information coupled with vestibule and proprioceptors all over the body goes to your cerebellum to be processed as balance
_______________: sense of smell
Olfaction
Describe the olfactory pathway
1 receptors for smell are the dendrites of CN1 and are located in the superior nasal cavity
2 pass through olfactory foramina
3 synapse at olfactory bulb
4 interpreted by temporal lobe of cerebral cortex
_______________: sense of taste
Gustatory pathway
Describe the gustatory pathway
Taste buds
CN VII (anterior tongue), CN IX (middle tongue), and CN X (back of tongue and throat)
Parietal lobe or cerebral cortex
Name the 3 layers of the eyeball
1 fibrous tunic
2 vascular tunic
3 nervous tunic
_______________: outer layer of the eye contains sclera and cornea
Fibrous tunic
_______________: middle layer of the eye contains vascular and pigmented structures
Vascular tunic
_______________: inner laters contains retina, rods, CN 1, and cones
Nervous tunic
Describe the location and function of the retina
Inner wall of the eyeball
Rods and cones
Describe the function and location of the iris
Regulates light coming in
Pigmented smooth muscle tissue
Location and function of lens
Posterior to the iris focuses by changing shape
Location and function of the aq humor
Fluid anterior to the lense which helps maintain shape and support
Location and function of the vitreous humor
Fluid posterior to the lens helps maintain shape and support
