Special Senses lecture Flashcards
Which receptors mediate touch, muscle stretch or contraction, joint position, and hearing+balance?
Mechanical receptors
Which receptor mediates pain, itch, taste, and smell?
Chemical receptors
_____ receptors: histamine makes you itch, histamine is a hormone that is chemical….
Chemical
Which receptor mediates body temperature and ambient temperature?
Thermal
Which receptor mediates wave of light to process vision stimulus?
Electromagnetic
Sub-classes of receptors allow us to detect what?
The quality of a sensation….ie. hot, cold? texture? intensity?
What does meisner’s corpuscle respond to?
Light touch, two point discrimination
What does merkel’s disk react to ?
Superficial pressure and light tough
What does pacinian corpuscle react to?
Deep pressure
What does ruffini corpuscle react to?
Skin stretch
What do free nerve endings react to?
Pain, itch, temperature
Visceral sensory receptors include which two sensations?
Pain and pressure
What do nocireceptors react to?
Pain (Free nerve endings)
What do mechanoreceptors react to (viscerally)?
Pressure (pacinian corpuscle
Olfactory receptor cells have ____ neurons
bipolar (two….two nostrils…..bi is two…)
Olfactory receptors are responsible for your sense of ___-
smell
Which nerve is responsible for your sense of smell? name and roman
Olfactory; I
Physiology: how do we smell things?
Dissolved odorants bind to receptor proteins
Physiology of smell: Which protein mechanism is activated? What does it proud as a second messenger?
G-protein; cAMP
Physiology of smell: cAMP opens ____ and ____ channels, causing depolarization of the receptor that then triggers ____
Na+ and K+; AP
Olfactory pathway: Mitral cells _____, ______, and relay signals along the olfactory tract to the ______ cortex (hypothalamus;amygdala;limbic system)
Amplify;refine;olfactory cortex
What are the receptor orange for sense of taste?
Taste buds
Where are taste buds found on the tongue?
Tops of fungiform papillae; side walls of foliate papillae; circumvallate papillae
Where are taste buds found, other than the tongue?
Palate, pharynx, epiglottis, upper 1/3 of the esophagus
Tongue has taste buds on the papillae, which is located in the _____
epithelium
How many taste cells does each taste bud contain?
100
Are taste cells electrically excitable after stimulation from a chemical?
Yes.
Name the five taste sensations
Sweet, sour, salt, bitter, umami
Which five basic taste sensation is this? Saccharin, alcohol, some amino acids
Sweet
Which five basic taste sensation is this? Hydrogen ions
Sour
Which five basic taste sensation is this? Metal ions
Salt
Which five basic taste sensation is this? alkaloids such as quinine and nicotine
BItter
Which five basic taste sensation is this? amino acids glutamate and aspartate
Umami
Physiology of taste: for a taste to occur, what must be dissolved in saliva?
A chemical
Physiology of taste: to be a taste, was must the dissolved chemical come in contact with?
Gustatory hairs
Physiology of taste: binding of the food chemical depolarizes the taste membrane, causing the release of a ________
neurotransmitter
Physiology of taste: after the release of a neurotransmitter, a general potential is initiated, which elicits an:
AP
_____ influxes in salty tastes
NA+
____ influxes in sour tastes by opening ____ channels
H+; Cation
Free answer: G-protein is with sweet, bitter, and umami tastes
:)
Gustatory pathway for taste uses which two cranial nerves?
VII(facial) IX(glossopharyngeal)
Cranial nerves VII and IX carry impulses from taste buds to the solitary nucleus of the _____
medulla
After reaching the medulla,, taste impulses travel to the _____ and from there, fibers branch to the _____ cortex in the insult, and the hypothalamus and limbic system
thalamus; gustatory
taste is ____% smell
80
Visual system includes extrinsic eye muscles and _____ ____
Lacrimal Apparatus
What is the conjunctiva?
Transparent membrane of the eye
The transparent membrane of the eye covers the _____ of the eyes
White
What does the conjunctiva produce?
A lubricating mucous secretion
The lacrimal gland and ducts connect to the ______ cavity
Nasal
Lacrimal secretion is the same as ___
tears
The eye has ____ extrinsic eye muscles, ____ rectus muscles, and ____ oblique muscles
6;4;2
Which muscles of the eye rotate the eyeball?
The two oblique muscles
How many layers does the wall of the eyeball contain?
THree
What are the three layers of the eyeball?
Fibrous, vascular, sensory
The internal cavity of the eyeball is filled with fluids called ____
Humors
Which separates the eye from the wall and internal cavity?
The lens
The outermost layer of the eyeball wall, the ____ layer, contains the _______ and _____
Fibrous, sclera and cornea
The _____ of the fibrous layer of the eyeball is the opaque posterior region, protests and shapes eyeball, and anchors extrinsic eye muscles
Sclera
The _____ of the fibrous layer has a transparent anterior 1/6 fibrous layer
Cornea
The ____ layer of the eyeball wall is the middle pigmented layer and has three regions: ______, ____ ____, and ____
Choroid, ciliary body, and iris
The ____ region of the Uvea supplies blood to all the layers of the eyeball
Choroid
The ____ region of the Uvea has brown pigment that absorbs light to prevent visual confusion
choroid
the ____ ____ region of the Uvea layer is a ring of tissue surround the lens
Ciliary body
the ____ ____ region of the uvea has ____ muscle bundles
ciliary body; smooth
The ____ region of the uvea is the colored part of the eye
Iris
The iris has the ____ pupillae which is the outer ring of smooth muscle, ______ due to the _____ stimulation
dilator; contracts; sympathetic
The iris has the _____ pupillae, an inner ring of smooth muscle and it contracts due to the parasympathetic stimulation
Sphincter
Which eye pupillae results in dilation of the pupil?
Dilator Pup.
Which eye pupillae results in constriction of the pupil?
Sphincter pup.
Which layer of the eye has photoreceptors that transduce light energy, and have cells that transmit and process signals: bipolar cells, ganglion cells
neural layer
The retina has ______ cell axons
ganglion
The retina has ganglion cell axons that leave the eye as the _____ nerve
optic
The optic disc is your ____ ____
blind spot
the optic disc lacks what?
Photoreceptors
The retina has ____ and ____
rods and cons
Are rods more numerous at the peripheral region of the iris?
No, region of the retina
Do rods operate in dim or bright light?
DIm
What time of vision do rods provide?
Indistinct, fuzzy, non color peripheral vision
Cones of the eye are found in ____ ____
macula lutea
Cones of the eye are found in the macula later, concentrated in the ____ _____
fovea centralis
cones of the eye operate in _____ light
bright
Cones provide high-acuity, ____ vision
color
Name the two sources of blood supply to the retina
Choroid; central artery
The ____ and ____ ___ separate the anterior and posterior segments of the eye
Lens and ciliary zone
The posterior segment contains ____ ____ that: transmits light, supports posterior surface of the lens, contributes to intraocular pressure
Vitreous humor
The anterior segment of the eye is composes of two chambers: ____ and_____
anterior; posterior
The anterior chamber of the eye is between the ____ and _____
cornea and iris
The posterior chamber of the eye is between the ____ and ____
iris and lens
The anterior segment od the eye contains _____ _____
aqueous humor
Aqueous humor of the anterior segment is plasma like fluid continuously filtered from _____
capillaries
________: compression of the retina and optic nerve if drainage of aqueous humor is blocked
Glaucoma
what part of the eye is biconvex, transparent, flexible, elastic, and avascular?
Lens
Lens allow what?
Precise focusing of light of the retina
What occurs as a consequence of aging, diabetes mellitus, heavy smoking, and frequent exposure to intense sunlight?
Cataracts
Light are packets of energy called?
Photons
Which two items in eyes respond to different wavelengths of the visible spectrum?
Rods and cones
What is bending of a light ray called?
Refraction
Light passing through a convex lens is bent so that the rays converge at a ____ point
focal
the “image” you see is actually what ___ ___ and reversed ___ to ___
upside down, reversed right to left
Light is refracted at the _____, entering and leaving the ____
Cornea; the lens
What allows for fine focusing of an image?
Change in lens curvature
Focusing for distant vision: are your ciliary muscles are relaxed or tense?
Relaxed
Focusing for distant vision: are your lens stretched flat by tension or bunched up?
Stretched flat
close vision focusing requires accommodation, constriction and _____, which is?
convergence, medial rotation of the eyeballs
Refraction problems.
Myopia: you can see better ____
Hyperopia: you can see better ____
closer up and farther back
Refraction problems. What is astigmatism caused by?
Unequal curvatures in different parts of the cornea or lens
In the eye, which part is sensitive to dim light?
Rods
What is best suited for night vision, rods or cones?
Rods
What perceives input in gray tones only? rods or cones?
Rods
When rods pathways converge, what happens?
Fuzzy and indistinct images
What allows rods to capture more light and allow them to amplify light signals more than cones?
Rods contain more photosensitive pigment than cones
Which needs bright light for activation, cones or rods?
Cones
Which contains one of three pigments that furnish vividly colored views, rods or cones?
Cones
When cones have nonconverging pathways, what occurs?
Detailed, high-resolution vision
Rods are ____ sensitive to light and cones are ___ sensitive to light
More;less
To be legally blind, do you need to lose rods or cones?
Cones
To be night blind, do you need to lose cones or rods?
Rods
What is the light-absorbing molecule that combines with one of the four proteins to form visual pigments called?
Retinal
Retinal is synthesized from which vitamin?
Vitamin A
How many isomers does retinal have?
Two (11-cis retinal and all-trans-retinal
What causes the transmission of electrical impulses in the optic nerve?
Conversion of 11-cis-retinal to all-trans-retinal
11-cis-retinal isomers are bent or straight?
bent
all-trans-retinals are bent or straight?
Straight
Rods, which are important for seeing in the dark, cause _____ to form and accumulate when in the dark
Rhodopsin (formed from vitamin A)
When does rhodopsin (in rods) break down?
When light is absorbed
Retinal and opsin separate during what?
The excitation of Rods
What are the three types of cones?
Blue, green, and red
In the dark, what binds to and opens cation channels in the outer segments of photoreceptor cells?
cGMP
After cGMP binds to and open cation channels in the outer segments of photoreceptor cells, which to elements influx to create a depolarizing dark potential and what is the mV?
Na+ and Ca+ // -40mV
Phototransduction:
In the light, light-activated _____ activates a g-protein called what?
Rhodopsin, and transducin
After rhodopsin activates transducin, what does that g-protein activate?
Phosphodiesterase
After transducin activates PDE, what does PDE do?
PDE hydrolyzes cGMP to GMP and releases it from sodium channels
After PDE hydrolyzes cGMP to GMP and its released from sodium channels, what happens?
Sodium channels close and the membrane hyperpolarizes to -70mV
In the retina, which two cells generate graded potentials? (your ESPS and IPSPS)
Photoreceptors and bipolar cells
What hyperpolarizes photoreceptor cells, causing them to stop releasing the neurotransmitter glutamate?
Light
After the photoreceptor cells are hyperpolarized, causing the release of glutamate, which cells are then allowed to depolarize and release glutamate onto ganglion cells?
Bipolar cells
Which cells in the retina generate AP’s that are then transmitted in the optic nerve?
Ganglion cells
Axons of which cell form the optic nerve?
Retinal Ganglion Cells
Which fibers decussate at the optic chiasma of the optic nerve?
Medial fibers
Most fibers of the optic tracts continue where?
To the later geniculate body of the thalamus
Visual pathway. What connect to the primary visual cortex in the occipital lobe?
Optic radiation fibers
Where do other optic tract fibers (not radiation fibers) send their branches to?
The midbrain, ending in the superior colliculi (initiating visual reflexes)
What are the three parts of the ear?
External, Middle (tympanic cavity) ear, and internal
Which two parts of the ear are involved with hearing?
External and middle
What is the internal ear responsible for?
Hearing and equilibrium
What two structures make up the external ear?
Helix (rim) and Lobule (ear lobe)
The external ear contains the external acoustic meatus, which is what?
The short, curved tube lined with skin bearing hairs, seb. glands, and ceruminous glands.
The ear drum is part of the external ear. What is it called? What kind of tissue is it made of? FUnction?
Tympanic membrane, connective tissue, and transfers sound energy to middle ear
The middle ear is a small, air filled, mucosa-lined cavity where?
In the temporal bone
The middle ear is flanked laterally by the ___ and medially by the bony wall containing the ____ and ____ windows
Eardrum; oval and round
The bony wall contains the oval and round windows. Round is _____
oval is _______
Cochlear and vestibular
What is the superior portion of the middle ear called?
Epitympanic recess
What is the auditory tube of the middle ear called? It connects the middle ear to the nasopharynx
Pharyngotypanic tube
What does the pharyngotympanic tube of the middle ear do?
Equalizes pressure in the middle ear cavity
Name the three small bones in the tympanic cavity.
Malleus, incus, and stapes
What do the three bones of the tympanic cavity do?
Transmit vibratory motion of the eardrum to the oval window
The internal ear contains what two main parts that each break down into other parts?
Bony labyrinth and then filled with perilymph
The bony labyrinth of the internal ear contains tortuous channels in which bone?
Temporal
The bone labyrinth of the internal ear has three parts. what are they?
Vestibule, semicircular canals, and cochlea
The perilymph of the internal ear is simply what within the bony labyrinth?
membranous sacs filled with a potassium-rich endolymph
The vestibule of the bony labyrinth is egg shaped and contains which two membranous sacs?
Saccule ; Utricle
The saccule and the utricle of the vestibule in the bony labyrinth are membranous sacs. Which one is continuous with the cochlear duct?
Saccule
The saccule and the utricle of the vestibule in the bony labyrinth are membranous sacs. Which one is continuous with the semicircular canals?
Utricle
The saccule and utricle of the vestibule in the bony labyrinth are membranous sacs that house which receptor regions? (named maculae) They also respond to gravity and changes in the position of the head.
Equilibrium
Semicircular canals of the bony labyrinth (and utricle sacs) have three canals that each define two-thirds of a circle. What are there names?
Anterior, lateral, and posterior
