special senses Flashcards
all special senses are located within a sensory organ; true or false?
true
bending of light by the cornea onto the retina
refraction
adjust for gaze distance
cornea: major adjustment
lens: fine tunes
accommodation
far accommodation is done with __ as the NT and ____ innervates it
NE; sympathetic
near accommodation is done with __ ____ and ____ system innervates it
Ach muscarinic; parasympathetic
what two muscles deal with pupillary reflex
sphincter and radial
the sphincter muscle is innervated by
parasympathetic and CN III
the radial muscle is innervated by what system
sympathetic
the three C’s of close vision
contract ciliary, constrict, converge
axons from the ___ ____ make up the optic nerve
ganglion cells
the blind spot is where
optic disk
most of the photosensitive cells are used for ___
vision
what opsin do rods specifically contain
rhodopsin
what opsin do cones specifically contain
iodopsin
what is the retinal in the dark (opsin + 11-cis retinal)
rhodopsin
where is the highest density of cones and highest acuity
fovea centralis
which of these is not true of the cones
a. have cones that code for red, gree, and blue
b. require bright light
c. contain opsin + 11-cis retinal
d. have poor contrast
have poor contast
exposure of light makes cis retinal into trans retinal; true or false?
true
what from of retinal activates transducin
11-trans-retinal
which of the following are not true of dark phototransduction
a. release of GLU relative to Ca
b. depolarization occurs in the dark
c. rhodopsin is active at all times
d. GLU is released during dark
rhodopsin is active at all times
without transducin being activated what is true?
a. there is high gCMP activity
b. Na and Ca enter the cell
c. photoreceptors release glutamate
d. all of the above
d. all of the above
when transducin is activated in the light what is true?
a. Na and Ca can enter the cell
b. K+ leak channels are closed
c. decreases cGMP activity
d. all of the above
c.
when voltage gated Ca channels close there is a decrease in release of ____ proportional to the amount of ____
GLU; light (bright light shuts all channels)
during dark adaptation the time required for vision to adjust is due to
revert to opsin + 11-cis retinal
night blindness is due to: inability of rods to adapt
vitamin A deficiency
ON-bipolar cells only do only ___ potentials
graded
which of these is true about ON- bipolar cells?
a. the GLU receptors are metabotropic
b. high GLU leads to bipolar inhibition and hyperpolarization
c. inhibited by GLU in dark
d. all of these are true
d. all of these are true
Light OFF bipolar cells are _____ GLU receptors
ionotropic
what is not true of bipolar cells
a. they receive info from multiple photoreceptors
b. one ganglion can receive info from many bipolar cells
c. in the fovea centralis there is convergence
d. ganglion cells have an ON and an OFF area
c
optic tracts carry info to ____
thalamus
what visual fields cross
temporal (nasal retina)
nasal visual fields have no _____
decussation
lens become clouded
cataracts
lens become harder
presbyopia
eyeball too long, concave lens
myopia
eyeball too short, convex lens
hyperopia
degeneration of optic nerve; higher production of aqueous humor; apoptosis of nerve cells
glaucoma
X linked recessive disorder, mutations in genes that code for red and green opsins
color blindness
what is true of determining pitch in the cochlea
a. topographical organization (spatial coding along basilar membrane)
b. low frequency sounds are closer to beginning of cochlea
c. lower dB results in more action potentials
d. all of the above
a. topographical organization (spatial coding along basilar membrane)
_____ of stereocilia against tectorial membrane (determines response to sound)
deformation
hair cells and photoreceptors are known as ____ _____ ____; they do not generate action potentials
special receptor cells
what do special receptor cells such as hair cells and photoreceptors do?
release NT
what is true of stereocilia?
a. they are positioned on the tectorial membrane
b. they can open mechanically gated K+
c. when they bend towards the kinocilia there is depolarization of hair cell
d. all of the above
d.
when a hair cell is depolarized and K+ is opened what occurs
voltage gated Ca channels release GLU; stimulates afferent neurons
the hair cell contains both mechanically and voltage gated channels; true or false?
true
which of these is not a type of conductive hearing loss
a. cerumen
b. otosclerosis
c. presbycusis
d. otitis media
c. presbycusis (hair cells; sensioneural)
what constitutes central hearing loss
CNS and auditory cortex issues
what two senses use kinocilium and K+
hearing and equilibrium
what structure controls head rotation and angular acceleration and deceleration
semicircular canals
the macula organs: utricle and saccule do what
linear acceleration and head tilt
which of these is not correct in the process of transmission of equilibrium position
a. endolymph moves immediately in direction of movement
b. endolymph places pressure on moving capula
c. capula in ampulla moves as body moves
d. stimulation causes stereocilia bends towards kinocilium
a
increased pressure in cochlea and vestibular apparatus causes dizziness and ringing in ears, what is this disease?
menieres disease
caused by free floating otoconia crystals that can adhere to the capula resulting in transient attacks of vertigo
benign paroxysmal positional vertigo
the chemoreceptors for olfaction are __ ____ receptors
G protein
the odor receptor proteins respond to multiple chemicals within the same ____
class
what is true of the transduction pathway of olfaction
a. there is no convergence between the 2° sensory neuron and the 1° sensory neuron
b. olfactory neurons detect odor stimulus
c. multiple types of olfactory receptor per 1° sensory neuron
d. all of the above
b
what is the olfactory pathway
neurons in the olfactory epithelium synapse through the cribiform plate to the glomerulus located within the olfactory bulb, then olfactory tracts carry info to brain
where is the major relay of olfaction compared to other cells
limbic system instead of thalamus
which of these structures plays a role in olfaction?
a. hippocampus
b. amygdala
c. limbic system
d. all of the above
d
the receptors for gustation are classified as
chemoreceptors
what are the five submodalities of taste
salty, sweet, bitter, umami, and sour
which of these is true about a type I receptor for gustation?
a. it is recognized by support cells that sense salt
b. the transduction is mediated by sodium channels which cause hyperpolarization
c. The NT is Ach
d. all of the above
a.
a type II pathway for gustation has what NT
possibly ATP
the transduction of a type II pathway is ___ ____
G protein
what does the type II pathway code for (tastants)
sweet, bitter, umami
what is true of the type III pathway for gustation?
a. transduction is mediated by a H+ channel
b. the neurotransmitter is seratonin
c. the presynaptic cells code for sour tastants
d. all of the above
d
facial nerve does ____ _ of taste perception on tongue
front 1/3
glossopharyngeal (IX) does posterior ___ of taste perception on tongue
2/3
the vagus (X) nerve does taste for
epiglottis
the gustation pathway goes to ___ to thalamus to ___
medulla; gustatory cortex
The testicals are in charge of what?
ds
