Exam 1 - Special Senses

Question 1

What is a diopter?

Answer 1

1 meter/focal length

Question 2

How do we express a convex lens vs a concave lens?

Answer 2

convex = + diopters
concave = - diopters

Question 3

Where is the greatest bend of light?

Answer 3

between air (1) & cornea (1.38)

Question 4

How do we increase refractive power?

Answer 4

Make it more convex. This is useful in seeing smaller/closer things (eyes roll in and pupils contract)

Question 5

What is presbyopia?

Answer 5

Loss of elasticity of lens with age (decreaing accommodation)

Question 6

Stimulation of what division of the ANS will increase refractive power of the lens?

Answer 6

Parasympathetic

Question 7

T/F: Ability to increase refractive power remains consistent through our life.

Answer 7

False!

Decreases as we age!
Age 10 = 14
Age 50 = 2

Question 8

What is an astigmatism?

Answer 8

An irregularly shaped cornea (more common) or lens (less common)

Question 9

What is emmetropia?

Answer 9

Normal vision but ciliary muscle is relaxed in distant vision (instead of contracted)

Question 10

In distant vision, what error of refraction can be compensated for by contraction of the ciliary muscle?

Answer 10

hyperopia - focal point behind retina (farsighted)

Need convex lens to correct (globe short/lens weak)

p.s. globe = eyeball

Question 11

What is myopia?

Answer 11

Focal point in front of retina (nearsighted)

Need concave lens to correct (globe long or lens strong)

Question 12

What is the dioptic power of a convex lens with a focal length of 0.1 meters?

Answer 12

+10 diopters

diopter = 1m/focal length; convex is +

Question 13

What is the dioptic power of a concave lens with a focal length of .1 meters?

Answer 13

-10 diopters

Question 14

What is the area of greatest visual acuity?

Answer 14

Fovea centralis

Question 15

T/F: All retinal cells generate action potentials.

Answer 15

False - only ganglion cells generate action potentials

Question 16

What is stereopsis?

Answer 16

binocular vision (requires 2 eyes)

Question 17

What is relative size?

Answer 17

The closer an object is, the larger it appears (learned from past experience)

Question 18

As the head moves, objects closer move across the visual field at a greater rate. This describes what type of depth perception?

Answer 18

Moving Parallax

Question 19

When light strikes a rod or a cone it ____ and neurotransmitters ____.

Answer 19

Hyperpolarizes; NTs decrease (less glutamate)

in photoreceptors

Question 20

In the dark, rods and cones _____ and neurotransmitters _____.

Answer 20

Depolarize; NTs increase (more glutamate)

in photoreceptors

Question 21

What is the function of a bipolar cell?

Answer 21

They connect photoreceptors to either ganglion cells or amacrine cells

Question 22

What are the two types of bipolar cells?

Answer 22

ON - hyperpolarized by NT glutamate (invaginating)

OFF - depolarized by NT glutamate (flat)

Question 23

Which ganglion cells are important in color vision?

Answer 23

P (X)

Majority of all ganglion cells

Question 24

What are the major features of P(X) cells? (input/response/receptor field/projection)

Answer 24

Input = bipolar
Rec. Field = Small
Response = slow adapting
Projection = Parvo of LGN

Question 25

What are the major features and function of M(Y) cells? (input/response/receptor field/projection)

Answer 25

``` Function = B&W: movement Input: Amacrine Rec. Field = Large Response = Fast adapting Projection = Magno (LGN) ``` **Minority of all ganglion cells**

Question 26

What are the major characteristics of W ganglion cells?

Answer 26

1. Smallest/slowest 2. 40% of ganglion cells 3. Broad receptive fields (most input from rods, helps with vision in dim light) 4. Detect directional movement 5. Act as light intensity detectors

Question 27

What cells may be responsible for center-surround antagonism?

Answer 27

Horizontal cells

Question 28

Which cells receive input from bipolar cells and project to ganglion cells?

Answer 28

Amacrine cells

Question 29

What neurotransmitters do amacrine cells release?

Answer 29

GABA, dopamine

Question 30

What is a loss of red cones?

Answer 30

Protanope

Question 31

What is a loss of green cones?

Answer 31

Deuteranope

Question 32

What are the functions of the superior colliculus pathway?

Answer 32

- Orienting reactions | - Rapid directional movement of both eyes

Question 33

What are the functions of the Pretectal Nuclei?

Answer 33

Reflex movement of the eyes - focus on objects of importance

Question 34

What are the functions of the suprachiasmatic nucleus?

Answer 34

Biologic clock fxn

Question 35

When is involuntary fixation mostly lost?

Answer 35

When the superior colliculus is destroyed

Question 36

What controls voluntary fixation?

Answer 36

The cortical field bilaterally in premotor cortex

Question 37

What causes mydriasis?

Answer 37

Sympathetic stimulation (increased pupil size)

Question 38

What causes miosis?

Answer 38

Parasympathetic stimulation (decreased pupil size)

Question 39

What are symptoms of Horner's syndrome?

Answer 39

- Constricted pupil to unaffected eye - Dilated blood vessels - Lack of sweating on affected side of face - Drooping of eyelid (interruption of SNS supply to an eye)

Question 40

Which extraoccular eye muscles adduct the eye when elevating/depressing?

Answer 40

The obliques - superior lowers the eye when adducted, inferior raises the eye when adducted

Question 41

Which extraoccular eye muscles abduct the eye when elevating/depressing?

Answer 41

Superior & Inferior rectus

Question 42

Which muscles work together to produce lateral eye movements?

Answer 42

Medial rectus of one eye + lateral rectus of another eye

Question 43

A lesion of the VI CN on the right would lead to...?

Answer 43

Double vision when the subject looks to the right

Question 44

What level of decibels does normal conversation occur?

Answer 44

60 dB

Question 45

What is the threshold of pain?

Answer 45

160 dB

Question 46

What is the greatest acuity for sound in adults?

Answer 46

1000-4000 Hz

Question 47

What frequency of sound is most likely heard by the human ear at 30dB?

Answer 47

1000 Hz

Question 48

What is impedence matching?

Answer 48

change in resistance between sound waves in air and sound vibrations generated in the cochlear fluid

Question 49

What is impedence matching a function of?

Answer 49

Ossicular System - Reduces amplitude - Increases pressure against oval window

Question 50

This muscle of the ossicles slows down transmission by pulling the stapes outward.

Answer 50

Stapedius Muscle

Question 51

This muscle of the ossicles enhances transmission by pulling the malleous inward.

Answer 51

Tensor Tympani

Question 52

If the tensor tympani and stapedius muscles work together, how is transmission affected?

Answer 52

Transmission slows down - activated by loud sound and speech

Question 53

What is attenuation of sound and how does it affect the cochlea?

Answer 53

CNS reflex (contraction of ossicle muscles) activated by loud sounds; protects cochlea from loud environment/low frequency sounds

Question 54

Which chamber(s) of the cochlea is filled with perilymph?

Answer 54

Scali Vestibuli and Scali Tympani

Question 55

Which chamber of the cochlea does not have a window?

Answer 55

Scali media

Question 56

What window is associated with scali vestibuli?

Answer 56

Oval window

Question 57

What separates Scali media from Scali vestibuli?

Answer 57

Reissner's membrane

Question 58

What separates scali media from scali tympani?

Answer 58

Basilar membrane

Question 59

What chamber of the cochlea is enriched with K+ ions?

Answer 59

Scali media

Question 60

Which chamber is associated with the round window?

Answer 60

Scali tympani

Question 61

Where is endolymph present?

Answer 61

Scali media (bathes top of hair cells)

Question 62

When would you say "you're making my basilar membrane bounce too much!!"?

Answer 62

If someone was being loud, because you are a nerd.

Question 63

What is the Place Principle?

Answer 63

Different sound frequencies displace different areas of the basilar membrane

Question 64

What is the function of the cochlea?

Answer 64

Change mechanical vibrations in fluid into action potentials in the VIII CN

Question 65

Which hair cells respond best to higher frequencies?

Answer 65

short & thick hair cells near oval window (base)

Question 66

Which hair cells respond best to lower frequencies?

Answer 66

long & slender hair cells near helicotrema (apex)

Question 67

How does the cochlea behave like a Fourier analyser?

Answer 67

Acts as an auditory prism (sorts out vibrations of different frequencies into different positions along the membrane

Question 68

Neurons in the anterior area of the primary auditory cortex respond best to what audible frequency sounds?

Answer 68

Low

Question 69

Neurons in the posterior area of the primary auditory cortex respond best to what audible frequency sounds?

Answer 69

High

Question 70

What are the major parts of the auditory pathway?

Answer 70

``` Cochlear Nucleus Superior Olivary Nucleus Nucleus of Lateral Lemniscus Inferior Colliculus Medial geniculate Primary Auditory Cortex ```

Question 71

Glycols, alcohols, aldehydes, ketones, would have what taste?

Answer 71

Sweet

Question 72

What taste is caused by ionized salts?

Answer 72

Salt

Question 73

What taste is caused by acids (H ion concentration)?

Answer 73

Sour

Question 74

What taste receptor responds to amino acids?

Answer 74

umami/savory

Question 75

What taste is caused by long chain organic compounds with N/ alkaloids?

Answer 75

Bitter (caffeine, nicotine, etc)

Question 76

What cranial N is associated with taste in the anterior 2/3 of the tongue?

Answer 76

VII - lingual n. to chorda tympani to facial (fuckin' right)

Question 77

What CN is associated with taste in the posterior 1/3 of the tongue?

Answer 77

CN IX (petrosal ganglion)

Question 78

What CN is associated with the base of the tongue/palate?

Answer 78

CN X

Question 79

What are the G protein linked taste receptors?

Answer 79

Sweet, bitter, umami

Question 80

What is Jacobson's organ?

Answer 80

Vomeronasal organ

Question 81

What is the function of olfactory cells?

Answer 81

- Bipolar nerve cells that project hairs in mucous in nasal cavity - Stimulated by odorants - Connect to olfactory bulb via cribiform plate

Question 82

What is the fxn of cells that make up Bowman's glands?

Answer 82

Secrete mucus

Question 83

What is the fxn of sustentacular cells?

Answer 83

Supporting cells (derp)

Question 84

What are the three characteristics of oderants?

Answer 84

1. Volatile 2. Slightly water soluble (for mucus) 3. Slightly lipid soluble (for membrane of cilia)

Question 85

As an olfactory cell is stimulated with an odorant, what prolongs depolarization?

Answer 85

Efflux of Cl-

Question 86

What is anosmia?

Answer 86

Odor blindness

Question 87

Where is the glomerulus located and what is its function?

Answer 87

Location: olfactory bulb Function: connects olfactory cell axons with dendrites of mitral and tufted cells -receives axons from olfactory cells -receives dendrites from large mitral cells, smaller tufted cells

Question 88

What inhibits cells of the olfactory tract?

Answer 88

Granule Cells

Question 89

Which cells send axons into the CNS via olfactory tract?

Answer 89

mitral and tufted cells (both continually active)

Question 90

Which cells receive input from centrifugal nerve fibers and may aid in localization of smell?

Answer 90

Granule cells

Question 91

What are inhibitory cells between glomerulus?

Answer 91

Periglomerular cells

Question 92

T/F: Olfactory fibers can directly penetrate into the limbic system.

Answer 92

True! Human odors can evoke recollection of past experience/mood/emotion.

Question 93

What is located in the lateral olfactory area?

Answer 93

Prepyriform & pyriform cortex - only sensory pathway to cortex that doesn't relay via thalamus

Question 94

What is the function of the Lateral olfactory area?

Answer 94

Learned control/aversion