Test 3: Sensory Systems

Front 1

What is a receptor potential?

Back 1

1. stimulate threshold to releases chemical messengers
2. doesn't directly trigger an action potential

Front 2

What is the difference between a graded potential and action potential?

Back 2

1. the strength of a graded potential is proportional to the strengh (or amoutn) of stimulus; size dependent
2. in an action potential, strength of stimulus has no effect on action potential; it also propagates

Front 3

Define: frequency code

Back 3

1. frequency of a nerve impulse receptor by the brain indicates magnitude of the stimulus

Front 4

Define: population code

Back 4

1. greater stimulus, greater number of receptors responding, more total impulses sent to CNS

Front 5

What type of receptors are in the ear?

Back 5

mechanoreceptors

Front 6

What are pacinian corpucles?

Back 6

1. sensitive to deep pressure that causes rapid movement of tissues
2. responds to displacement of the connective tissue

Front 7

Define: statocysts

Back 7

1. gravity receptors
2. lined with ciliated mechanoreceptors (statoliths)
3. deal with hairs

Front 8

Describe mechanoreceptors

Back 8

1. sense displacement
2. causes a receptor potential/ and or action potential to send to CNS
3. by knowing which cells are firing, the animal knows its orientation

Front 9

What are the structures in the outer ear of a human?

Back 9

1. pinna
2. external auditory meatus
3. tympanic membrane

Front 10

What are the structures in the middle ear of a human?

Back 10

1. tympanic membrane
2. malleus, incus, and stapes
3. auditory lobe

Front 11

What are the structures in the inner ear of a human?

Back 11

1. oval window (begining)
2. vestibule
3. vestibular apparatus
4. cochlea

Front 12

What comprises the vestibular structures?

Back 12

1. utricle
2. saccule
3. semicircular canals

Front 13

What comprises teh cochlea

Back 13

1. oval window
2. scala vestibuli
3. scala media
4. scala tympani
5. round window

Front 14

Describe: cochlea

Back 14

contain mechanoreceptors hair cells that detect pressure waves

Front 15

What are the types of equilibrium the ear detects?

Back 15

1. static
2. dynamic

Front 16

What is static equilibrium?

Back 16

1. detects movement of the head from the resting, upright position
2. reliant on gravity

Front 17

What is dynamic equilibrium?

Back 17

1. movement through space
2. rotational movement

Front 18

Which direction does the utricle detect?

Back 18

horizontal

Front 19

Which direction does the saccule detect?

Back 19

verticle

Front 20

What comprises the saccule?

Back 20

1. otoliths
2. cupula
3. sterocilias
4. kinocilium
5. vestibular branch of cranial nerve 8 (vestibulochochlear)

Front 21

Describe: saccule

Back 21

1. detect change in position
2. head tilted or body moving in a straight line
3. stimulate hair cells that sends signals to the brain
4. animal able to perceive direction of gravity

Front 22

Describe: otoliths

Back 22

pull of gravity causes otoliths to press sterocilia, stimulating them; sensitive to gravity and linear accelartion

Front 23

Describe: cupula

Back 23

enclose sterocilia; mass of gelatinous material secreted by hair cells

Front 24

Describe: stereocilia

Back 24

short hair like projections

Front 25

Describe: kinocilium

Back 25

single, long projection

Front 26

What comprises the semicircular canals?

Back 26

1. cupula (flexion)
2. hair cell (stereocilia and kinocilium)
3. results of rotational movement
4. vestibular branch of cranial never 8

Front 27

Describe: cupula

Back 27

1. by membraneous fluid
2. causes hyperpolarization or depolarization
3. call tell directional movement

Front 28

Describe: hair cells

Back 28

1. mechanoreceptors
2. detect movement
3. help maintain position and equilibrium
4. 1 long kinocilium and many shorter stereocilia

Front 29

What comprises cochlear structure?

Back 29

1. oval window
2. scala vestibuli
3. scala tympani
4. round window

Front 30

Describe: organ of Corti

Back 30

1. located in inner ear
2. cells rest on basilar membrane
3. tectorial membrane (ear drum)
4. 18,000 hair cells (or auditory sensory cells)
5. fluid wave and initiation of action potential
6. chochlear division of cranial nerve 8

Front 31

Describe: basilar membrane

Back 31

1. pitch
2. loudness

Front 32

Define: pitch

Back 32

1. distance/length of sign wave

Front 33

Define: loudness

Back 33

1. volume
2. amplitude

Front 34

What kind of receptor is gustation (taste)?

Back 34

chemoreceptor

Front 35

Describe structure of taste buds

Back 35

1. specialized epithelial cells with 100 taste receptor cells
2. g-protein signal transduction

Front 36

What is the most sensitive modality?

Back 36

bitter

Front 37

What is the least sensitive modality?

Back 37

sweet

Front 38

What are the modalities of gustation?

Back 38

1. sweet
2. sour
3. salty
4. bitter
5. umami

Front 39

What ion is associated with each modality?

Back 39

1. sweet - K
2. sour - Ca
3. salt - Na
4. bitter - K and H

Front 40

Describe ion reception in g-protein transduction of gustation

Back 40

ex: sugar

1. sugar molecule binds to receptor in plasma membrane of taste receptor cell
2. G-protein activated and activates adenylyl cyclae
3. ATP converted to cAMP
4. cAMP activates protein kinase and closes K+ channels

Front 41

Which cranial nerves are associated with taste buds?

Back 41

7, 9, and 10

Front 42

What type of receptors sense smell?

Back 42

chemoreceptors

Front 43

Describe: olfaction

Back 43

1. receptors
2. olfactory nerve 1
3. bipolar neurons
4. replacement very 60 days
5. cribriform plate of ethmoid bone
6. olfactory bulb
7. olfactory tract; ciliated
8. fasted adapting sense

Front 44

Describe odorant molecules and receptor activity

Back 44

1. odor binds to receptor in plasma membrane of olfactory cell
2. G protein is activated adn activates adenylyl cyclase
4. ATP converted to cAMP
5. GAted Na+ channels open, leading to depolarization

Front 45

What are the types of eyes in the animal kingdom?

Back 45

1. eye spots (ocelli)
2. compound eye
3. camera eyes
4. direct eyes
5. indirect eyes

Front 46

Describe: eye spots

Back 46

1. used to detect light and dark
2. don't form images

Front 47

Describe: compound eyes

Back 47

1. have a lense that allows them to form an image
2. mosaic picture
3. can easily detect motion

Front 48

Describe: camera

Back 48

1. humans
2. direct and indirect eyes

Front 49

Describe: human eye structure

Back 49

1. tunics
2. conjunctiva
3. cornea
4. iris
5. pupil
6. lens
7. aqueous humor
8. vitreous humor
9. receptors
10. fovea
11. optic nerve (cranial nerve 2)

Front 50

Describe: conjunctiva

Back 50

1. clear mucous membrane
2. covers the sclera

Front 51

Describe: cornea

Back 51

1. front surface of eye
2. becomes thinner, transparent
3. where light enters

Front 52

Describe: iris

Back 52

1. smooth muscle
2. causes pupil to change size

Front 53

Describe: pupil

Back 53

light-opening

Front 54

Describe: lens

Back 54

1. grows constantly
2. too dense--cataracts

Front 55

Describe: aqueous humor

Back 55

1. fluid between cornea and lens

Front 56

Describe: vitreous humor

Back 56

1. fluid between lens and retina

Front 57

Describe: optic nerve

Back 57

1. cranial nerve 2
2. blind spot

Front 58

1. What are the components of the tunics?

Back 58

1. sclera
2. choroid
3. retina

Front 59

Describe: retina

Back 59

1. two layers = pigmented and nervous
2. light sensitive

Front 60

Describe: choroid

Back 60

1. pigmented
2. absorbs energy

Front 61

Describe: sclera

Back 61

"white" of the eye

Front 62

Describe characteristics of the lens

Back 62

1. suspensory ligaments
2. ciliary body
3. accomodation

Front 63

What is a ciliary body?

Back 63

1. choroid thickens and projects medially into eyeball
2. consists of ciliary process and muscles

Front 64

What is accommodation?

Back 64

1. ability to change focus for near or far vision by changing shape of lens
2. accompanied by ciliary body contracting/relaxing to change thickness
3. focusing of image on retina, or more so, fovea

Front 65

Describe: fovea

Back 65

highest number of cones (color vision)

Front 66

Describe affect that sympathetic and parasympathetic fibers have on accommodation

Back 66

1. Parasympathetic: contracts ciliary muscles causing constriction of pupil; to focus on close object
2. Sympathetic: relaxes ciliary muscles to dilate pupil to focus on distant object

Front 67

Describe affect that sympathetic and parasympathetic fibers have on pupil dilation

Back 67

1. sympathetic: dilate pupil
2. parasympathetic: constrict

Front 68

What are focusing abnormalites?

Back 68

1. emmetropia (normal)
2. myopia
3. hyperopia
4. astigmatism
5. presbyopia

Front 69

Describe: myopia

Back 69

1. near sightedness
2. image focused in front of retina

Front 70

Describe: hyperopia

Back 70

1. far sighted
2. image focused behind retina

Front 71

Describe: astigmatism

Back 71

1. irregularity in curvature of cornea
2. affects focusing (inability to focus well)

Front 72

Describe: presybopia

Back 72

1. can't accommodate lens
2. comes with old age

Front 73

What are some photoreceptors?

Back 73

1. specialized neurons in the retina capable of phototransduction
2. ex: rods and cones

Front 74

Describe: cones

Back 74

1. 6.5 million in human eye
2. most located in fovea
3. conical shaped
4. responsible for color reception
5. not as sensitive as rods, but have better spatial resolution
6. respond to light at a higher level of intensity
7. modality: red, green, and blue overlapping
8. photopigment (scotopsin)

Front 75

Describe: rods

Back 75

1. 125 million in human eye
2. found in periphery of retina
3. cylindrical
4. see shades of gray (not sensitive to color)
5. function in dim light so we can detect shape and motion
6. photopigment (retinal)

Front 76

What are the cells in retina?

Back 76

1. receptor cells
2. bipolar cells
3. horizontal cells
4. amacrine cells
5. ganglion cells

Front 77

Describe: optic chiasm

Back 77

1. optic nerve switches to optic tract
2. linked information joined together to send to brain
3. crossing over of medial

Front 78

How do sound waves get detected in the ear?

Back 78

1. sound waves enter external auditory canal
2. tympanic membrane vibrates
3. malleus, incus, and stapes amplify the vibration
4. oval window vibrates
5. vibrations are conducted via fluid
6. basilar membrane vibrates
7. corti hair cells are stimulated
8. cochlear nerve transmits impulses to brain

Front 79

What is the pathway of vision?

Back 79

1. light passes through cornea
2. through aqueous fluid
3. through lens
4. through vitreous body
5. image forms on photoreceptor cells in retina
6. signal bipolar cells
7. signal ganglion cells
8. optic nerve transmits signals to thalamus
9. integration by visual areas of cerebral cortex

Front 80

What are bipolar cells?

Back 80

1. transmit signals from the photoreceptors to ganglion cells
2. make synaptic contact with ganglion cells

Front 81

What are horizontal cells?

Back 81

1. integrate and regulate input from multiple photoreceptor cells
2. responsible for seeing well in bright and dim light
3. receive information from receptor cells and send it to bipolar cels

Front 82

What are amacrine cells

Back 82

1. interneurons
2. responsible for 70% of input to ganglion cells
3. regulate bipolar cells
4. receive information from bipolar cells and send signals back to bipolar or ganglion cells

Front 83

What are ganglion cells?

Back 83

1. unite to form optic nerve
2. receive information from photoreceptors via bipolar and amacrine cells
3. collectively transmit visual information to regions in the brain

Front 84

What is phototransductioin?

Back 84

process by which light is converted into electrical signals in photoreceptors

Front 85

When do photoreceptors depolarize?

Back 85

in the dark

Front 86

When do photoreceptors hyperpolarize?

Back 86

in the light

Front 87

Describe the phototransduction process in the dark

Back 87

1. depolarization in the dark
2. opens voltage gated Ca channels and Na channels
3. release neurotransmitter glutamate into synaptic cleft

Front 88

How do photoreceptors hyperpolarize?

Back 88

1. the closing of the sodium channels causes hyperpolarization
2. hyperpolarization of cells causes voltage gated Ca channels to close
3. as Ca levels drop, so do glutamate levels
4. the decrease in glutamate levels causes the depolarization of "On" centers on bipolar cells, and hyperpolarization of "Off" centers