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