Ch. 27 The Senses LearnSmart
sensory adaption
1. a refrigerator seems noisy 2. you live with the appliance for a while 3. you do not perceive a hum from the refrigerator
stages of sensing taste in the order that they occur
1. dissolved food molecule stimulate taste receptor cells 2. receptor cells transmit information to sensory neurons 3. sensory neurons send information to the cranial nerves 4. input is relayed through the thalamus 5. input arrives at gustatory cortex, which interprets tastes
explain how light becomes vision
1. light passes through the pupil 2. light is focused by the lens 3. rod and cone cells are stimulated 4. bipolar cells are stimulated 5. ganglion cells are stimulated 6. action potentials are transmitted to the brain by the optic nerve
transmitting stimuli from the eye to the brain from visual processing
1. pigments in photoreceptors absorb light energy and stimulate bipolar neurons 2. ganglion cells receive messages from bipolar neurons, modified by amacrine and horizontal cells 3. axons of ganglion cells send impulses to the brain via the optic nerve 4. the impulses arrive at the thalamus 5. the signals are relayed to the primary visual cortex for processing
process of sound transduction
1. sound is trapped and funneled 2. the eardrum is vibrated 3. bones amplify the incoming sound 4. the oval window is vibrated
transmission of sound through the inner ear
1. the oval window transfers vibrations to the cochlea 2. fluid in the canals moves 3. the basilar membrane vibrates 4. hair cells move relative to the tectorial membrane 5. as the cilia bend, the hair cells initiate action potentials in the auditory nerve
how acceleration is sensed
1. there is an acceleration (change in velocity) of the head 2. calcium carbonate granules and fluid in the utriole and saccule move 3. cilia on hair cells lining the utricle and saccule bend 4. neurons are activated 5. signals are sent along the auditory nerve to the brain
What nerve carries signals from the cochlea to the thalamus and then eventually to the cerebral cortex for processing?
Auditory
The hole in the middle of the iris is called the _______, which changes in size depending on the brightness of light
Pupil
Select the similarities of olfaction and gustation
Stimulus molecules are dissolved in liquid before binding to neurons, they are both stimulated by molecules, and they are both types of chemoreception.
for any single type of olfactory receptor, how many odorant molecules can it bind?
a small set of molecules
The _______ lies between the cornea and the lens
aqueous humor
the ______ canal funnels sound waves from the outer ear to the eardrum
auditory
sound waves trapped by the outer ear and funneled by the ____ vibrate the eardrum
auditory canal
the semicircular canals of the inner ear play a role in sensing
balance (tilt or rotation)
What inner ear structure contains mechanoreceptors called hair cells
basilar membrane
what inner ear structure contains mechanoreceptors called hair cells
basilar membrane
What is the function of the lens?
bend light entering the eye
select all the functions of the vitreous humor
bend light rays and focus them on the retina and press the retina against the choroid
what is the only part of the body that doesn't have pain receptors?
brain
select the two main divisions of the nervous system
central and peripheral
to detect food and danger, bacteria and protists use a sense that is a lot like ______, which is probably the most ancient sense
chemoreception
what sense was most likely the first to evolve in organisms?
chemoreception
what correctly describes olfactory receptors
chemoreceptors in the epithelium of the nasal cavity
the layer of the eye immediately internal to the sclera is called the _______, which becomes the iris at the front of the eye behind the cornea
choroid
in the ear, mechanoreceptors are specialize epithelial cells with hairlike extensions called
cilia
What responds to moving fluid in the semicircular canals?
cilia on hair cells
select all the functions of the aqueous humor
cleanse and nourish the cornea and lens, bend light rays to help focus them on the retina, and maintain the shape of the eye
The ______ is the complex inner ear structure that consists of three fluid-filled ducts and transduces sound into neural impulses
cochlea
the cochlea contains the ______ canal, the _____ canal, and the ________ canal.
cochlear, vestibular, and tympanic
when there is a deficiency of pigments sensitive to red and green wavelengths, what condition results?
color blindness
________ cells are the color-detecting photoreceptor cells in vertebrate eyes and are concentrated near the center of the retina
cone
chemoreceptors
detect chemicals, such as those involved in smell and taste
proprioceptors
detect position of limbs and head
pain receptors
detect tissue damage, extreme heat and cold
after sound waves are trapped by the outer ear, they travel down the auditory canal and vibrate the
eardrum
in the ear, sound waves that vibrate the _____ in the auditory canal are then amplified by three small ______ in the middle ear called the hammer, anvil, and stirrup
eardrum, bones
what is the purpose of a pheromone?
elicit responses in members of the same species
photoreceptors gathered into cup-shaped eyes
flatworm
what best describes pain receptors?
free nerve endings
Select all the structures that sense touch.
free nerve endings and encapsulated dendrites
the intensity of a stimulus is conveyed to the brain by the ______ of incoming action potentials.
frequency
temperature is sensed with thermoreceptors that
have free nerve endings
sounds of different pitches cause vibrations _____ within the cochlea, and the brain interprets the different input as sounds of different pitches
in different areas
where is acceleration of the head sensed within the ear?
in the utricle and saccule
what constitutes a sensation?
input to the central nervous system
eyes containing thousands of ommatidia that each contain their own lens and form a tiny image
insect
Select all of the following that affect taste of a food.
intensity of chemical stimulus and pattern of receptors that are stimulated
what describes perception?
interpretation of sensations
at the front of the vertebrate eye, the choroid becomes the _____, which is the colored part of the eye
iris
the shape of what eye structure is adjusted by muscles when the eye is changing focus from a faraway object to a close object?
lens
photoreceptor
light
what causes macular degeneration?
loss of photoreceptors in the center of the retina
in an age-related condition called _______, a progressive loss of photoreceptors in the center of the retina leads to a loss of central vision
macular degeneration
what condition can result when the brain receives contradictory signals about motion from the inner ear and the eyes?
motion sickness
select all the stimuli that can be detected by pain receptors
noxious chemicals, extreme cold, chemicals from damaged cells, and mechanical damage
eye with a single lens that focuses light onto photoreceptors at the back of the eye
octopus
the _______ nerve connects each retina with the brain
optic
what is the sclera?
outermost layer of the eye
when sound waves vibrate the eardrum and cause the middle ear bones to move, the stirrup pushes on the
oval window
on the tongue, taste buds can be grouped into _______, raised bumps that contain numerous chemoreceptors
papillae
a(n) _______ is a chemical used for communication between different individuals of the same species.
pheromone
what type of sensory receptors are present in the eye and allow animals to see?
photoreceptors
mechanoreceptor
physical deflection
what causes neural impulses that allow the sense of vision?
pigments change shape
propriocepter
position
when a proprioceptor fires an action potential, what information is it sending to the brain?
position of a body part
what causes sensory adaption?
prolonged exposure to a stimulus
sensory neurons called _____ tell the brain the positions of joints, tendons, and muscles and also the direction the head is facing
proprioceptors
Taste buds are groupings of ______ that synapse with sensory neurons, which relay information to cranial nerves
receptor cells
each olfactory neuron expresses one type of
receptor protein
the binding of a specific type of odorant molecule to the ______ of an olfactory neuron causes a change that can trigger an action potential
receptor protein
sensory ________ are special types of sensory cells that can detect stimuli
receptors
what is the purpose of an eye layer called the tapetum that is present in some animals?
reflect light to give the eyes of nocturnal animals another chance to transduce light
what is the purpose of the muscles attached to the lens?
regulate curvature of the lens
photoreceptors
respond to light; involved in vision
mechanoreceptors
respond to physical deflection; involve in touch and hearing
thermoreceptors
response to temperature
the innermost layer of the eye is a sheet of photoreceptors called the
retina
a common light-sensitive pigment found in the photoreceptors of animal eyes is
rhodopsin
_______ cells are photoreceptors that respond to dim light and enable vision at night
rod
In the retina, the ________ cells contain rhodopsin, and the _______ cells contain different rhodopsin-like pigments that absorb blue, green, or red light
rod, cone
The outer covering of the eye, or ________, is modified into the ________, a transparent window on the front of the eye
sclera, cornea
The ______ canals of the vestibular apparatus detect whether the head is rotating or tilting.
semicircular
dizziness occurs when you stop moving because the fluid in the _______ is still in motion
semicircular canals
A raw input that arrives at the CNS is a(n)
sensation
chemoreceptor
small molecules
the senses of ________ are similar in that they both use chemoreceptors, and in both the stimulus molecules dissolve in a watery solution
smell and taste
Select the three middle ear bones
stirrup, anvil, and hammer
select the five primary taste sensations in humans
sweet, unami, salty, sour, and bitter
select the true statement about taste buds
taste buds sense all of the primary tastes but respond strongly to one or two
how is pitch interpreted from sound?
the basilar membrane vibrates in different regions as a result of different pitches
sensory neurons relay sensory information about odors from
the olfactory bulb to the olfactory cortex
free nerve endings in the skin act as ________. sensory receptors that detect temperature
thermoreceptors
what effect do local anesthetics have on the nervous system?
they stop pain-sensitive neurons from transmitting action potentials in a limited area of the body
true or false: most taste buds sense all of the primary tastes
true
how are unencapsulated neurons different from encapsulated neurons
unencapsulated neurons have free nerve endings
the ______ apparatus of the inner ear contains the utricle, saccule, and semicircular canals, which allow the body to detect balance and motion
vestibular
in the inner ear, the utricle and saccule are pouches of the _______ that detect ______
vestibular apparatus, acceleration
loud sounds results in more _______ through the basilar membrane
vibrations