Chapter 12

Question 1

stimulus

Answer 1

sensory input that causes some change within or outside the body. a form of physical energy such as heat, pressure or sound waves but can also be chemical.

Question 2

receptor

Answer 2

a structure specialized to receive certain stimuli. accepts the stimulus and converts its energy into another form

Question 3

sensation

Answer 3

we become consciously aware of the stimulus

Question 4

perception

Answer 4

understanding what the sensation means

Question 5

Mechanoreceptors

Answer 5

respond to forms of mechanical energy, such as waves of sound, changes in fluid pressure, physical touch or pressure, stretching or forces generated by gravity and acceleration

Question 6

Thermoreceptors

Answer 6

respond to heat or cold

Question 7

Pain receptors

Answer 7

respond to tissue damage or excessive pressure or temperature

Question 8

Chemoreceptors

Answer 8

respond to the presence of chemicals in the nearby area

Question 9

Photoreceptors

Answer 9

respond to light

Question 10

receptor adaptation

Answer 10

sensory neuron stops sending impulses even though the original stimulus is still present

Question 11

somatic sensations

Answer 11

originate from receptors present at more than one location in the body . include temp, touch, vibration, pressure, pain and awareness of body movements and position

Question 12

5 special senses

Answer 12

taste, smell, hearing, balance, and vision. originate from receptors that are restricted to particular areas of the body, such as the ears and eyes.

Question 13

Unencapsulated dendritic endings

Answer 13

naked dendritic endings of sensory neurons around hairs and near the skin surface signal pain, light pressure, and changes in temp.

Question 14

Merkel disks

Answer 14

Detect light touch and pressure. are modified unencapsulated dendritic endings

Question 15

Pacinian corpuscles

Answer 15

several kinds of dendritic endings are encapsulated (enclosed) in epithelial or connective tissue. theses are best known. encapsulated receptors located in the dermis that respond to either deep pressure or high-frequency vibration

Question 16

Meissner’s corpuscles

Answer 16

encapsulated touch receptors located closer to the skin surface than Pacinian corpuscles. detect the beginning and the end of light pressure and touch

Question 17

Ruffini endings

Answer 17

Encapsulated receptors that respond continually to ongoing pressure

Question 18

muscle spindles

Answer 18

best known of these mechanoreceptors are the specialized structures for monitoring muscle length

Question 19

referred pain

Answer 19

happens because action potentials from internal pain receptors are transmitted to the brain by the same spinal neurons that transmit action potentials from pain receptors in the skin and skeletal muscles

Question 20

taste buds

Answer 20

about 10,000 are located at the surface of many of these folds. cluster of about 25 taste cells and 25 supporting cells that separate the taste cells from each other

Question 21

olfactory receptor cells

Answer 21

odors are detected. located in the upper part of the nasal passages

Question 22

outer ear

Answer 22

consists of the pinna, or visible portion of te ear, and auditory canal. receives and channels sound

Question 23

tympanic membrane (eardrum)

Answer 23

serves as a partition between the outer and middle ears

Question 24

middle ear

Answer 24

consists of an air-filled chamber within the temporal bone of the skull, bridged by 3 small bones called the malleus (hammer, incus (anvil), and stapes (stirrup). amplifies sound

Question 25

oval window

Answer 25

stapes touches this smaller membrane, causing it to vibrate

Question 26

auditory tube

Answer 26

a narrow tube that runs from the middle ear chamber to the throat. usually enclosed but opens briefly when you yawn or swallow to equalize air pressure.

Question 27

inner ear

Answer 27

sorts sounds by tone and converts them into impulses. senses rotation movements and converts them into impulses. senses static position and linear acceleration and deceleration; converts them into impulses

Question 28

cochlea

Answer 28

sound is converted. shaped a bit like a snail.

Question 29

basilar membrane

Answer 29

supports population of about 15,000 hair cells, mechanoreceptor cells of the ear

Question 30

tectorial membrane

Answer 30

composed of a firm, gelatinous, noncellular material, convert air waves to impulses.

Question 31

vestibular apparatus

Answer 31

a system of fluid-filled canals and chambers. consists of 3 semicircular canals for sensing rotational movement of the head and body and an area called vestibule

Question 32

utricle and saccule

Answer 32

2 fluid filled chambers of the vestibule. respond to linear acceleration and deceleration as well as static position.

Question 33

otoliths

Answer 33

are embedded in the gel near the gel's surface, unattached to the bone wall of the vestibule

Question 34

cornea

Answer 34

light passes through the cornea and space filled with fluid called aqueous humor that nourishes and cushions the cornea and lens

Question 35

iris

Answer 35

colored, disk-shaped muscle that determines how much light enters the eye, or passes through the pupil

Question 36

pupil

Answer 36

the adjustable opening in the center of the iris

Question 37

lens

Answer 37

a transparent, flexible structure attached by connective tissue fibes to a ring of circularly arranged smooth muscle called the ciliary muscle

Question 38

retina

Answer 38

absorbs light and converts it into impulses

Question 39

optic nerve

Answer 39

transmits impulses to the brain

Question 40

fovea

Answer 40

contains greatest concentration of photoreceptors

Question 41

optic disk

Answer 41

blind spot where optic nerve exits eye

Question 42

accommodation

Answer 42

refers to the adjustment of lens curvature so we can focus on either near or far objects

Question 43

Myopia

Answer 43

nearsightedness

Question 44

hyperopia

Answer 44

farsightedness

Question 45

astigmatism

Answer 45

is due to an abnormal curvature of either the cornea or the lens

Question 46

4 layers of retina

Answer 46

1. outermost layer consists of pigmented celss that along with the choroid absob light not captured by the phtotoreceptor cells 2. layer of photoreceptor cells called rods and cones because of their shape 3. rods and cones synapse with the 3rd layer, layer of neurons called bipolar cells 4. innermost layer consists of ganglion cells. are also neurons. their long axons become the optic nerve going to the brain

Question 47

rhodopsin

Answer 47

rods all have the same photopigment called this

Question 48

nerve deafness

Answer 48

sounds cannot be converted into impulses in sensory nerves

Question 49

conduction deafness

Answer 49

sound waves simply are not transferred to the inner ear at all. is frequently due to arthritis of the middle ear bones