Chapter 16: Sense Organs

Question 1

sensory receptors

Answer 1

structure is specialized to detect a stimulus, some are bare nerve endings and others are true sense organs

Question 2

What is the electrical signal on a nerve?

Answer 2

action potential

Question 3

What kind of energy is the output energy of cell receptors?

Answer 3

electrical

Question 4

transduction

Answer 4

conversion of one form of energy to another

Question 5

receptor potential

Answer 5

small local electrical charge on a receptor cell brought by an initial stimulus

Question 6

sensation

Answer 6

a subjective awareness of the stimulus

Question 7

What are the somatosensory projection pathways?

Answer 7

1. First Order neurons- from body, enter dorsal horn of spinal cord via spinal nerves
2. Second order neurons- decussation to opposite side in spinal cord, ends in thalamus
3. third order neurons- thalamus to primary somesthetic cortex of cerebellum

Question 8

modality

Answer 8

type of stimulus of the sensation it produces
-vision, hearing, taste

Question 9

location

Answer 9

encoded by which nerve fibers are issuing signals to the brain

Question 10

receptive field

Answer 10

area that detects stimuli for a sensory neuron

Question 11

intensity

Answer 11

encoded in 3 ways:which fibers are sending signals, how many fibers are doing so, and how fast these fibers are firing

Question 12

duration

Answer 12

how long the stimulus lasts

Question 13

sensory adaptation

Answer 13

if stimulus is prolonged, the firing of the neuron gets slower over time and we become less aware of the stimulus

Question 14

phasic receptor

Answer 14

generate a burst of action potentials when first stimulated , then quickly adapt and sharply reduce or stop signaling even though stimulus continues

Question 15

tonic receptor

Answer 15

adapt slowly and generate nerve signals more steadily

Question 16

fast pain

Answer 16

myelinated fibers
-sharp localized stabbing pain perceived w/ injury

Question 17

slow pain

Answer 17

-unmyelinated fibers
-longer lasting dull feeling
-somatic pain arises from skin
-visceral pain from stretch, chemical irritants

Question 18

endogenous opioids

Answer 18

produced by CNS under stress, found in dorsal horn of spinal cord, acts as neuromodulators blocking the transmission of pain
-enkephalinm, endorphins

Question 19

gustation

Answer 19

sensation of taste resulting from the action of chemicals in the taste buds

Question 20

filiforms

Answer 20

no taste buds and important for texture

Question 21

foliate

Answer 21

no taste buds

Question 22

fungiform

Answer 22

at rear of tongue and contain 1/2 of taste buds

Question 23

basal cells

Answer 23

stem cells that replace taste cells every 7-10 days

Question 24

supporting cells

Answer 24

resemble took cells w/o taste hairs, synaptic vesicles, or sensory roles

Question 25

What sense has the only neurons in the body directly exposed to the external environment?

Answer 25

the nose

Question 26

What is the only sense that can bypass the thalamus and go straight to the cerebral cortex?

Answer 26

the nose

Question 27

outer ear

Answer 27

includes auricle and external auditory meatus, ends at eardrum

Question 28

middle ear

Answer 28

air-filled space containing auditory ossicles has oval window and auditory tube

Question 29

inner ear

Answer 29

passageways in temporal bone, filled with perilymph and houses the vestibule, semicircular canals, and the cochlea

Question 30

parts of the external ear

Answer 30

auricle/pinna external auditory meatus tympanic membrane

Question 31

auricle/pinna

Answer 31

elastic cartilage covered w/ skin

Question 32

external auditory meatus

Answer 32

lined with hairs and ceruminous glands produce cerumen

Question 33

tympanic membrane

Answer 33

sound waves cause it to vibrate border between external and middle ear -eardrum

Question 34

oval window

Answer 34

connection between middle ear and inner ear

Question 35

auditory tube

Answer 35

equalizes pressure

Question 36

ossicles

Answer 36

malleus, incus, stapes

Question 37

inner ear

Answer 37

passageways in temporal bone filled w/ perilymph -include the vestibule, semicircular canals, and cochlea

Question 38

vestibule

Answer 38

contains saccule and utrile

Question 39

saccule

Answer 39

continuous with cochlear duct -located in vestibule

Question 40

utricle

Answer 40

continuous with semicircular canals

Question 41

semicircular canals

Answer 41

line each canal and communicate with the utricle

Question 42

cochlea

Answer 42

the three parts are scala vestibuli, scala media, and scala tympani

Question 43

scala vestibuli

Answer 43

abuts the oval window and contains perilymph

Question 44

scala media

Answer 44

contains endolymph and cochlear duct

Question 45

scala tympani

Answer 45

terminates at the round window and contains perilymph

Question 46

sound

Answer 46

any audible vibration of molecules, vibrating object pushes air molecules into eardrum

Question 47

frequency

Answer 47

how fast sound waves occur

Question 48

amplitude

Answer 48

the size of sound waves, loudness

Question 49

Which membrane vibrates with sound?

Answer 49

basilar membrane

Question 50

Pathway of Sound

Answer 50

sound travels through the auditory canal and hits the tympanic membrane, goes to the malleus where it vibrates the incus, the incus vibrates the stapes which lies on the oval window, the scala vestibule and the perilymph vibrates the basilar membrane and the pressure of the fluid is relieved by the round window

Question 51

conduction deafness

Answer 51

blocked sound conduction to the fluid of the internal ear

Question 52

sensorineural deafness

Answer 52

damage to the neural structures at any point from the cochlear hair cells to the auditory cortical cells

Question 53

tinnitus

Answer 53

ringing or clicking sound in the ear in the absence of auditory stimulus

Question 54

static equilibrium

Answer 54

perception of head orientation

Question 55

dynamic equilibrium

Answer 55

perception of motion or acceleration

Question 56

What mechanism perceives linear acceleration?

Answer 56

the macula

Question 57

What mechanism perceives angular acceleration?

Answer 57

crista

Question 58

crista ampullaris

Answer 58

sensory organ of rotation

Question 59

What mechanism perceives nearly half of all visual info?

Answer 59

cerebral cortex

Question 60

palpebral fissue

Answer 60

separates eyelids

Question 61

lacrimal caruncle

Answer 61

contains oil and sweat glands

Question 62

conjunctiva

Answer 62

mucous membrane that lines the eyelids and covers anterior surface of eyeball

Question 63

What are the 3 layers of the wall of the eyeball?

Answer 63

fibrous, vascular, sensory

Question 64

fibrous layer/tunica fibrosa

Answer 64

contains sclera and cornea

Question 65

vascular layer/tunica vasculosa

Answer 65

contains choroid, ciliary body, and iris

Question 66

sensory layer/tunica interna

Answer 66

contains retina and optic nerve

Question 67

sclera

Answer 67

protects and shapes eyeball

Question 68

cornea

Answer 68

bends light as it enters the eye and contains numerous pain receptors

Question 69

choroid region

Answer 69

supplies blood to all layers of the eyeball

Question 70

ciliary body

Answer 70

holds lens shape and suspensory ligaments holds lens in place

Question 71

iris

Answer 71

colored part of the eye, has pupil which regulates the amount of light

Question 72

retina

Answer 72

contains rods and cones

Question 73

rods

Answer 73

responsible for black and white, night vision

Question 74

cones

Answer 74

photopic and day vision

Question 75

optic disc

Answer 75

has no receptor cells and called the blind spot

Question 76

refraction

Answer 76

bending of light rays

Question 77

emmetropia

Answer 77

eyes relaxed and focused on distant object receive parallel light waves and focus w/o effort

Question 78

near response

Answer 78

focus on object closer

Question 79

myopia

Answer 79

nearsighted

Question 80

myopia

Answer 80

nearsighted

Question 81

hyperopia

Answer 81

farsighted