Neuroscience Exam 2

Front 1

Frequency

Back 1

The number of sound waves or other discrete events per second, expressed in
hertz (Hz)

Front 2

Retina

Back 2

A thin layer of cells at the back of the eye that transduces light energy into neural activity

Front 3

Pupil

Back 3

The opening that allows light to enter the eye and strike the retina (1mm to 8mm)

Front 4

Iris

Back 4

The circular, pigmented muscle that controls the size of the pupil in the eye

Front 5

Cornea

Back 5

The transparent external surface of the eye. Light rays are refracted at the cornea

Front 6

Sclera

Back 6

The tough outer wall of the eyeball; the white of the eye

Front 7

Extraocular Muscle

Back 7

A muscle that moves the eye in the orbit; 3 sets (Superior Oblique)

Front 8

Conjunctiva

Back 8

The membrane that folds back from the eyelids and attaches to the sclera of the eye

Front 9

Optic Nerve

Back 9

The bundle of ganglion cell axons that passes from the eye to the optic chiasm

Front 10

Optic Chiasm

Back 10

The structure in which the right and left optic nerves converge and partially cross to form the optic tracts

Front 11

Optic Tract

Back 11

A collection of retinal ganglion cell axons stretching from the optic
chiasm to the brain stem.

Front 12

Optic Disk

Back 12

(Blind Spot) - The location on the retina where optic nerve axons leave the eye

Front 13

Macula

Back 13

In the eye, a yellowish spot in the middle of the retina with relatively few large blood vessels; contains the fovea

Front 14

Fovea

Back 14

The pit or depression in the retina at the center of the macula; in humans, the
fovea contains only cone photoreceptors and is specialized for high acuity vision

The fovea is the most central part of the retina and is specialized for high-resolution vision and contains only cones

Front 15

Nasal Retina

Temporal Retina

Back 15

side of eye nearer to the nose

side of eye nearer to the ear

Front 16

Aqueous Humor

Back 16

The fluid between the cornea and the lens of the eye

Front 17

Lens

Back 17

The transparent structure lying between the aqueous humor and the vitreous humor that enables the eye to adjust its focus to different viewing distances

Front 18

Vitreous Humor

Back 18

The jellylike substance filling the eye between the lens and the retina

Front 19

Ciliary Muscles

Back 19

A muscle that controls the shape of the eye lens

Front 20

Diopter

Back 20

A unit of measuremnt for the refractive power of the eye; the reciprocal of the
focal distance

Front 21

Accomodation

Back 21

The focusing of light by changing the shape of the eye lens

Front 22

Visual Field

Back 22

Total amount of space that can be viewed by the retina when the eye is fixated straight ahead OR the total region of space viewed by both eyes when the eyes are fixated on a point

Front 23

Visual Acuity

Back 23

The ability of the visual system to distinguish between two nearby points

Front 24

Visual Angle

Back 24

A way to describe the distance across the retina; an object that subtends
an angle of 3.5 degrees will form an image on the retina that is 1mm across

Front 25

Photoreceptors

Back 25

(Light sensitive) - A specialized cell in the retina that transduces light
energy into changes in membrane potential AND the only light sensitive type of cell in the retina

Front 26

Bipolar Cells

Back 26

In the retina, a cell that connects photoreceptors to ganglion cells. There are two types; OFF and ON. All bipolar cells receive DIRECT synaptic input from a cluster of photoreceptors and INDIRECT input from photoreceptors via intermediate horizontal cells

Front 27

Ganglion Cells

Back 27

(output to brain) - A cell in the retina that receives input from bipolar cells and sends an axon into the optic nerve

Front 28

Horizontal Cells

Back 28

A cell in the retina of the eye that projects neurites laterally in the outer plexiform layer

Front 29

Amacrine Cells

Back 29

A neuron in the retina of the eye that projects neurites laterally in the inner plexiform layer

Front 30

Ganglion Cell Layer

Back 30

A layer of the retina closest to the center of the eye, containing ganglion cells

Front 31

Inner Plexiform Layer

Back 31

A layer of the retina of the eye, located between the ganglion cell layer and the inner nuclear layer; contains the neurites and synapses between bipolar cells, amacrine cells, and ganglion cells

Front 32

Inner Nuclear Layer

Back 32

A layer of the retina of the eye containing the cell bodies of biploar,horizontal, and amacrine cells

Front 33

Outer Plexiform Layer

Back 33

A layer of the retina of the eye between the inner nuclear layer and the outer nuclear layer; contains the neurites and synapses between photoreceptors, horizontal cells, and bipolar cells

Front 34

Outer Nuclear Layer

Back 34

A layer of the retina of the eye containing the cell bodies of photoreceptors

Front 35

Layer of Photoreceptor Outer Segments

Back 35

A layer of the retina of the eye containing the light-sensitive elements of the photoreceptors

Front 36

Rods

Back 36

A photoreceptor in the retina containing rhodospin and specialized for low light levels AND 1000 times more light sensitive than cones AND outnumber cones 20:1

Front 37

Cones

Back 37

A photoreceptor in the retina containing one of three photopigments that are maximally sensitive to different wavelengths of light. Cones are concentrated in the fovea, specialized for daytime vision, and responsible for all color vision

Front 38

Scoptic Conditions

Photopic Conditions

Back 38

Nighttime lighting, dark, rods are used

Daylight lighting, light, cones are used

Front 39

Central Region of Retina

Peripheral Region of Retina

Back 39

Central is Fovea; all cones, no rods

Peripheral has more rods to cones and more photoreceptors to ganglion cells AND more
sensitive to light because rods are specialized for low light and more photoreceptors
feeding info to each

Front 40

Phototransduction

Back 40

Absorbed light energy is transduced into changes in photoreceptor membrane potential (around -30mv)

Front 41

Dark Current

Back 41

The inward sodium current that occurs in photoreceptors in the dark AND influx of Na+, stimulated by cGMP

Front 42

cGMP

Back 42

A second messenger, stimulates dark current, light reduces cGMP, leading to the closing of NA channels and a hyper polarization of the membrane

Front 43

Trichromatic Theory

Back 43

Young-Helmhotz Trichromatic theory states that the brain assigns colors based on a comparison of the readout of the three types of cone photoreceptors

Front 44

Dark Adaptation

Light Adaptation

Back 44

The process by which the retina becomes more sensitive to light in dim light

The process by which the retina becomes less sensitive to light in bright light conditions AND calcium role

Front 45

OFF Bipolar Cells

ON Bipolar Cells

Back 45

Depolarize in response to "light off" (Glu-gated-channels) AND a bipolar cell of the retina that depolarizes in response to dark (light off) in the center of its receptive field


Depolarize in response to "light on" (G-protein coupled receptors) in the center of its receptive field

Front 46

Receptive Field

Back 46

The region of a sensory surface (retina, skin) that, when stimulated with light, changes the membrane potential of a neuron AND measured in mm of retina or degrees of visual field

Front 47

Center-Surround Receptive Fields

Back 47

A visual receptive field with a circular center region
and a surround region forming a ring around the center; stimulation of the center
produces a response opposite that generated by stimulation of the surround

Front 48

P-type Ganglion Cells

Back 48

A type of ganglion cell in the retina characterized by a small cell body and dendritic arbor, a sustained response to light, and sensitivity to
different wavelengths of light AND "Parvo", 90% of ganglion cells, sustained response and slower conduction, stimulus form and detail

Front 49

M-type Ganglion Cells

Back 49

A type of ganglion cell in the retina characterized by a large cell body and dendritic arbor, a transient response to light, and no sensitivity to different wavelengths of light AND "Magno", 5% of ganglion cells, transient response and faster conduction, detection of stimulus movement

Front 50

NonM-NonP Ganglions Cells

Back 50

A ganglion cell in the retina that is not of the M or P type, based on cell morphology and response properties. Of the variety of cell types in this
category, some are known to be sensitive to the wavelength of light

Front 51

Color-Opponent Cells

Back 51

A cell in the visual system with an excitatory response to wavelengths of light of one color and an inhibitory response to wavelengths of another color; the color pairs that cancel each other are red-green and blue-yellow

Front 52

Parallel Processing

Back 52

The idea that different stimulus attributes are processed by the brain in parallel, using distinct pathways

Front 53

Retinofugal Projection

Back 53

A neural pathway that carries information away from the eye

Front 54

Visual Hemifield

Visual Field

Binocular Visual Field

Back 54

The half of the visual field to one side of the fixation point (Right and Left visual field)

The total region of space viewed by both eyes when the eyes are fixated on a point

The portion of the visual field viewed by both eyes

Front 55

Superior Colliculus

Optic Tectum

Back 55

A structure in the optic tectum of the midbrain that receives direct retinal input and controls saccadic eye movements AND involved in orienting responses, for example eye and head movements toward a visual stimuli

A term used to describe the superior colliculus, particularly in non mammalian vertebrae

Front 56

Retinotectal Projection

Back 56

A neural pathway that carries information from the retina to the superior colliculus

Front 57

Lateral Geniculate Nucleus (LGN)

Back 57

A thalamic nucleus that relays information from the
retina to the primary visual cortex

Front 58

Primary visual cortex - striate cortex- V1 - Brodmanns area 17

Back 58

located on the pole of the occipital lobe

Front 59

Stellate Cells

Pyramidal Cells

Back 59

2 types of cells in cortex:

A neuron characterized by a radial, star like distribution of dendrites

A neuron characterized by a pyramid shaped cell body and elongated dendtric tree; found in cerebral cortex AND only pyramidal cells send axons to other parts of the brain

Front 60

Optic Radiation

Back 60

A collection of axons coursing from teh lateral geniculate nuclues to
the visual cortex

Front 61

Parvocellular LGN Layers

Back 61

a layer of the LGN receiving synaptic input from P type retinal ganglion cells

Front 62

Magnocellular LGN Layers

Back 62

a layer of the LGN receiving synaptic input from M type retinal ganglion cells

Front 63

Koniocellular Layers

Back 63

a layer of the LGN containing very small cells, lying just ventral (bellow) to each magnocellular and parvocellular layer

Front 64

Ocular Dominance Columns

Back 64

A region of striate cortex receiving information predominantly from one eye AND left and right eye inputs to layer IVC remain segregated

Front 65

Retinotopy

Back 65

The topographic organization of visual pathways in which neighboring cells on the retina send info to neighboring cells in a target structure

Front 66

Simple Cell

Back 66

A neuron found in primary visual cortex that has an elongated orientation selective receptive field with distinct ON and OFF sub regions

Front 67

Orientation Selectivity

Back 67

The property of a cell in the visual system that responds to a limited range of stimulus orientations

Front 68

Orientation Column

Back 68

A column of visual cortical neurons stretching from layer II to layer VI that responds best to the same stimulus orientation

Front 69

Direction Selectivity

Back 69

The property of cells in the visual system that respond only when stimuli move within a limited range of directions

Front 70

Complex Cells

Back 70

A type of visual cortical neuron that has an orientation selective receptive field WITHOUT distinct ON and OFF sub regions

Front 71

Magnocellular Pathway

Back 71

A visual information processing pathway that begins with M type retinal ganglion cells and leads to layer IVB of striate cortex; believed to process info about object motion and motor actions AND disruptions in the magnocellular pathway may be associated with dyslexia

Front 72

Parvo-interblob Pathway

Back 72

A visual information processing pathway that begins with P
type retinal ganglion cells and leads to the interblob regions of striate cortical layer III; believed to process info about fine object shape

Front 73

Blob

Back 73

A collection of cells, mainly in the primary visual cortical layers II and III,
characterized by high level of the enzyme cytochrome oxidaze

Front 74

Blob Pathway

Back 74

A visual information processing pathway that passes through the
Parvocellular and Koniocellular layers of the LGN and converges on the blobs of striate cortical layer III; believed to process info about object color

Front 75

A Cortical Module

Back 75

the unit of cerebral cortex that is necessary and sufficient to analyze one discrete point in a sensory surface (2x2mm)

Front 76

Dorsal Stream

Back 76

The analysis of visual motion and the visual control of action AND the "where"

Front 77

Ventral Stream

Back 77

Is thought to be involved in the perception of the visual world and the recognition of objects AND the "what"

Front 78

Area MT / V5

Back 78

An area of neocortex, at the junction of the parietal and temporal lobes, that
receives input from primary visual cortex and appears to be specialized for the
processing of object motion; also called V5; all cells are direction-selective

MT Cells are direction selective and have large receptor fields

Front 79

Akinetopsia

Back 79

Damage to area MT selectively disrupts the perception of motion

In this disorder the person affected by it cannot perceive motion.

Imagine the effects of a strobe light and how you do not seem to detect motion, but rather see a series of still images

Front 80

Area V4

Back 80

An area of neocortex, anterior to striate cortex, that is in the ventral
visual processing stream and appears to be important for both shape perception and color perception

Area V4 is a component of the ventral stream. It is important for the perception of form and color

Front 81

Achromatopsia

Back 81

Damage to V4 selectively disrupts the perception of color

is the inability to see color. Although the term may refer to acquired disorders such as color agnosia

a partial or complete loss of color vision despite the presence of normal functional cones in the retina.

Front 82

Prosopagnosia

Agnosia

Back 82

Deficit in face recognition
AND difficulty recognizing faces even though vision is otherwise normal

Failure of knowledge or recognition (visual agnosia) Other sensory modalities (touch, smell) may substitute for vision

Front 83

Inferotemporal Cortex / Area IT

Back 83

An area of neocortex on the inferior surface of the temporal lobe, that is part
of the ventral visual processing stream; contains neurons with responses to complex objects, including faces, and appears to be involved in visual memory

Front 84

Layer IVB

Back 84

relatively large receptive fields, transient responses to light, and direction selectivity

Front 85

Audition

Back 85

The sense of hearing

Front 86

Vestibular System

Back 86

The neural system that monitors and regulates the sense of balance
and equilibrium

Front 87

Hertz (Hz)

Back 87

The unit of sound frequency equivalent to cycles per second. Average 20hz-20000hz AND related to Pitch
Frequency - pitch

Front 88

Intensity

Back 88

The amplitude of a sound wave. Sound intensity is the amplitude of the pressure differences in a sound wave that perceptually determines loudness AND related to loudness

Front 89

Pinna

Back 89

The funnel shaped out ear, consisting of cartilage covered by skin

Front 90

Auditory Canal

Back 90

A Channel leading from the Pinna to the Tympanic Membrane: the entrance to the internal ear

Front 91

Tympanic Membrane

Back 91

(Eardrum) - A membrane at the internal end of the auditory canal that moves in response to variations in air pressure

Front 92

Ossicle

Back 92

One of 3 small bones in the middle ear

Malleus "Hammer"
Incus "Anvil"
Stapes "Stirrup"

Front 93

Oval Window

Back 93

A hole in the bony cochlea of the inner ear, where movement of the ossicles is transferred to movement of the fluids in the cochlea

Front 94

Cochlea

Back 94

A spiral bony structure in the inner ear that contains the hair cells that transduce sound

Front 95

Middle Ear

Back 95

The Tympanic Membrane plus the Ossicles

Front 96

Outer Ear

Back 96

The Pinna and the Auditory Canal

Front 97

Inner Ear

Back 97

The cochlea, which is part of the auditory system, plus the labrynith, which is part of the vestibular system

Front 98

Medial Geniculate Nucleus (MGN)

Back 98

A relay nucleus in the thalamus through which all auditory information passes on its way from the inferior colliculus to the auditory cortex

Front 99

Primary Auditory Cortext

Back 99

A1/Brodmanns area 41
ON the superior surface of the temporal lobe

Front 100

Eustachian Tube

Back 100

An air filled tube connecting the middle ear to the nasal cavaties

Front 101

Attenuation Reflex

Back 101

The contraction of muscles in the middle ear, resulting in a reduction in auditory sensitivity

Front 102

Round Window

Back 102

A membrane convered hole in the bony cochlea of the inner ear that is continuous with the scala tympani and the cochlea AND movement of the oval window is accompanied by a corresponding movement at the round window

Front 103

Scala Tympani

Back 103

A chamber of the cochlea that runs from the Helicotreme to the round Window

Front 104

Helicotreme

Back 104

A hole in the apex of the cochlea in the inner ear that connects the Scala Tympani to the Scala Vestibuli

Front 105

Scala Vestibuli

Back 105

A chamber in the cochlea that lies between the Oval Window to the Helicotrema

Front 106

Scala Media

Back 106

A chamber in the cochlea that lies between the Scala Vestibule and the Scala Tympani

Front 107

Basilar Membrane

Back 107

A membrane seperating the Scala Tympani and Scala Media in the cochlea in the inner ear AND organized according to place code for frequency AND 2 main properties determine how the Basilar Membrane responds to sound: width and stiffness

Front 108

Reissners Membrane

Back 108

The cochlear membrane in the inner ear that seperates the Scala Vestibule from the Scala Media

Front 109

Organ of Corti

Back 109

An auditory receptor organ that contains hair cells, rods of Corti, and supporting cells

Front 110

Tectorial Membrane

Back 110

A sheet of tissue that hangs over the Organ of Corti in the cochlea in the inner ear

Front 111

Perilymph

Back 111

The fluid that fills the Scala Vestibule and Scala Tympani in the cochlea in the inner ear containing low K+ and high Na+ concentrations

Front 112

Endolymph

Back 112

The fluid that fills the Scala Media in the Cochlea of the inner ear, containing high K+ and low Na+ concentrations

Front 113

Hair Cells

Back 113

An auditory cell that transuces sound into a change in membrane potential

Front 114

Stereocilia

Back 114

Hairlike cilium attached to the top of a hair cell in the inner ear

Front 115

Reticular Lamina

Back 115

A thin sheet of tissure in the inner ear that hold the tops of hair cell sin the Organ of Corti

Front 116

Inner Hair Cells

Back 116

An auditory cell, primary transducer of sound into an electrochemical signal AND connects to about 95% of spiral ganglion cells

Front 117

Outer Hair Cells

Back 117

An auditory receptor cell located farher in the inner ear AND there are 3 times more outer hair cells than inner AND connects to about 5% of the spiral ganglion cells

Front 118

Spiral Ganglion

Back 118

A collection of neruons of the cochlea that receives input from hair cells and sens output to the cochlear nuclei in the medulla via the auditory nerve AND makes synaptic contacts with hair cells

Front 119

Auditory Nerve

Back 119

Consisting of axons projecting from the spiral ganglion to the cochlear nuclei

Front 120

Cochlear Amplifier

Back 120

Outer hair cells, including hte motor proteins in the outer hair cell membrane, that amplify displacements of the basilar membrane in the cochlea

Front 121

Otoacoustic Emissions

Back 121

Sounds produced by movements of the basilar membrane in the absense of an external auditory stimulus

Front 122

Characteristic Frequency

Back 122

The sound frequency to which a neuron in the auditory system gives its greatest response

Front 123

Tonotopy

Back 123

The systematic organization within an auditory structure on the basis characterstic frequency

Front 124

Duplex Theory of Sound Localization

Back 124

The principle that 2 schemes function in sound localization; interaural time delay at low frequencies and interaural intensity difference at high frequencies

Front 125

Wernickes Area

Back 125

Specialized for the interpretation of spoken language. Loss of this area results in serious disruptions of linguistic function

Front 126

Mechanoreceptors

Back 126

Any sensory receptor selective for mechanical stimuli, such as hair cells of the inner ear, various receptors of the skin, and stretch receptors of the skeletal muscle

Front 127

Spinal Segments

Back 127

Sets of dorsal and ventral roots plus the portion of the spinal cord related to them
There are 30 spinal segments, divided into 4 groups:
Cervical 8
Thoracic 12
Lumbar 5
Sacral 5

Front 128

Dermatome

Back 128

A region of skin innervated by the pair of dorsal roots from one spinal segment

Front 129

Dorsal Column-Medial Lemniscal Pathway

Back 129

An ascending somatic sensory pathway that mediates information about touch, pressure, and vibration AND path to the brain of info about mechanical stimulation of the skin

Front 130

Trigeminal Nerves

Back 130

Attaches to the pons and carries primarily sensory axons from the head and mouth AND somatic sensation of the face does not travel through the spinal chord but instead through Trigeminal Nerves

Front 131

Primary Somatosensory Cortex

Back 131

Part of parietal lobe AND surface of the cortex represents a map of the surface of the body (Somatotopy)

Front 132

Merzenich Experiment

Back 132

The somatotopic map in S1 can change in response to changes in
sensory inputs; the ability of cortex to adapt to changing conditions of input is of
central importance in our ability to conitinously learn new skills and recover from
bodily injury or from damage to the brain itself. Page 405

Front 133

Nociceptors

Back 133

Any receptor selective for potentially harmful stimuli, may induce sensations of pain; relay signals related to bodily injury; activiation of nociceptors can lead to pain
Different Types oF Nociceptors:
Polymodal
Mechanical
Thermal
Chemical

Front 134

Hyperalgesia

Back 134

A reduces threshold to pain, an increased response to painful stimuli, or a spontaneous pain that follows localized injury AND the increased sensitivity of a part of the body to nociceptive stimuli

Front 135

Afferent Regulation

Back 135

Pain is regulated
Pain evoked by nociceptive receptor activity can be reduced simultaneous activity in some mechanoreceptors AND feels good to rub bruise

Front 136

Descending Regulation

Back 136

Pain Regulation
Activity of some brain regions can cause Analgesia (Absence of pain), Suppression of pain, located in the PAG of the brain

Front 137

Endogenous Opiods

Back 137

Pain Regulation
Systemic application of opiods results in profound analgesia. Opiods bind to opiod receptors in teh brain. The brain then produces endorphons

Front 138

Endorphins

Back 138

produce analgesia
morphine like substance
relate to pain