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Flashcards in Neuro3Jordan Deck (122):
1

What 4 things do we use to classify peripheral axons?

Fiber diameter
Myelin thickness
Conduction Velocity

and what waves they use to contribute to an action potential
Thicker = faster

2

What type of fiber, sensory or motor, contains Aalpha, Agamma, B, and C?

What about Aalpha, Abeta, Adelta, and C?

Motor = AABC

Sensory = AAAC

3

What is a slowly adapting fiber?

Rapidly adapting?

Responds to prolonged and constant stimulation

Responds to beginning and end of a stimulus or intensification

4

What mechanoreceptor interprets fine, light touch and proprioception? Where are they located? What do they look like? Receptive field size?

- Meissner Corpuscles
- Glabrous (hairless) skin (Superficial)
- Large, myelinated fibers, adapt quickly.
- Receptive field is small

5

What mechanoreceptor interprets vibration and pressure? Where are they located? What do they look like? Receptive field?

-Pacinian Corpuscles
- Deep skin, ligaments, joints. (Deep)
- Large, myelinated, quick adaptors
- Look like onions
- Large receptive fields

6

What mechanoreceptor does (visceral?) pain and temperature?
Pressure, deep static touch and proprioception?
Pressure, slippage of objects, and joint angles?

Free nerve endings

Merkel discs

Ruffini corpusles

7

How does a pre-synaptic inhibition work?

Inhibitory neuron releases GABA --> Cl- influx --> hyperpolarization --> less Ca+ --> Less NT release

8

What are the functions of S1, S2 and PTO?

S1 - initial processing, position sense, size and shape discrimination
S2 - integration of many processes into larger schemes; comparison between objects and memory, cognitive touch
PTO - emotional responese; spatial coordinates of self, names objects.

9

Which Cortical processing unit can be altered, and how is this arranged?

S1 can be grown or diminished with practice. It is arranged in teh hounculus

10

Most (Primary sensory) cortex projections go to:
For the purpose of: ?

Thalamus via corticothalamic axons

Focuses activity

11

What are cortico- cortical projections

links primary and association areas of sensory; processes multiple info at once

12

What are corticofugal projections?

Cortex --> thalamus, medulla, SC
inhibit and prevent sensory intensity

13

What is the structur eof a free nerve ending? What about the types?

Lack specialized capsules or cells
- Peptidergic
- Non peptidergic

14

Which type of nociceptor receptor is most cutaneous nerve endings?

non-peptidergic

15

What ions are allowed through on the TRP nocicpeotrs?

Ca, Na, K

16

What is a nociception channel that allows sodium through?
ATP?
H+?

What are 3 other ligands that can act as noxious stimuli?

NaV
P2X
ASIC

Histamin, bradykinin, SP & CGRP

17

What NTs are relased by C fibers and alpha delta fibers onto interneurons? What receptor do the interneurons hav?

Alpha delta fibers: EAA only

C fibers: EAA and SP, CGRP

Receptor: AMPA

18

The gate control theory is specific to what pain fibers?

C fibers
and Ab, that excite the inhibitory post synaptic neuron

19

What is the mechanism of rubbing a painful spot to decrease stuff?

Ab fiber by normal stimuli --> Synapse on inhibitory interneuron --> EAA --> internuron release Glyicine --> Reduces sensation of pain.

20

What is the mechanism of descending inhibition?

PAG --> LC (NE) Raphe Nuclei (Serotonin) --> secondary inhibitory interneuron --> opiods --> Mu receptor on C fiber --> Reduce nociception

21

How can PAG be activated?

EAA, opiates, Cannabinoids

22

HOw does bradykinin influence chronic pain? (2)

Increase inflammation via vasodilation

Mediates NGF (nerve growth factor) --> production of BDNF, which is an NT that binds to TrkA

23

Nociception interpretation happens in what area of the brain? Damage of this causes what?

Insular cortex.

Asymbolia - pain without unpleasantness

24

What is afterdischarge?

Discharge of neural impulses after termination of initating simulation?

25

Monosynaptic or polysynaptic?

Stretch
GTO

DTRs Stretch = mono
GTO = poly

26

Golgi tendon organ is used for what sensation? What fiber type?

Nuclear bag fiber?

Chain Fiber?

Ruffini Corpuscle?

GTO:
tension
Ib

Nuclear bag:
Annulospiral, length and speed of length
Ia

Chain:
Flowerspray
length only, tension
II

Ruffini:
Limb position, joint movements. I

27

What sensory fiber of the msucle spindle is the primary afferent fiber?

1a, from annulospiral fibers

28

When a muscle is contracted, the muscle spindle is loose. What tightens that back up? Why do we need to tighten it?

gamma motor neurons. Makes sensory portions sensitive again .

29

What is the reaction of muscle spindles in a UMN to cause spasticity? Rigidity?

The gamma motor neurons are constantly activated.

Rigidity: Alpha motor Neurons continuous activation (inhibitory cortical influences are messed up)

30

What causes decorticate lesioning? ANd what is the pt sxs?

Sx: Flexor position
Cause: Internal capsule stroke above superior colliculus. Severe brain damage.

31

What causes decerebrate lesioning? Sx?

Sx: Extensor position, (worse prognosis)
Cause: lesion below red nucleus, on postural centers.

32

Where are central pattern generator cells located?

In the Spinal Cord.

33

Where does the dorsal pathway go to?
Ventral?

Parietal/Prefrontal cortex

Inferior temporal cortex

34

When reaching for an object, what isthe motor pathway in the cortex?

V1 --> Along dominant neurons (either visual or motor or both) --> AIP, PFG --> F5

35

We talk about columns all the time, but in different places they are differnet hings.

In the cortex the columns are organized:

Primary motor columns?

Visual columns?

Cortex: They go through the entire 6 layers, but IV receives input and V/VI output.

Primary motor Cortex:
has one column with 2 types of neurons in it, one to start motion, one to maintain motion

Visual columns:
- Excited by angles of light, and prefer one eye over the other
- Third spatial dimension adds depth to vision

36

Which of the 3 motor complexes can switch strategies in the middle of a movement? This itself has 2 separate divisions, wha tare they and their fxns?

Supplementary motor complex

SMA: Sets motor programs for learned sequences

pSMA: Learns the new complex sequences

37

What part of teh cerebellum ensures proper execution of coordinated movements and anticipates future body position in a feed forward manner? What if this is lesioned? What nuclei are used? What are the inputs?

Spinocerebellar!

Lesion: truncal ataxia

Nuclei:
fastigial, globose, emboliform

Inputs: spinocerebellar tract, spinal trigeminal, visual and auditory systems

38

What part of the cerebelum sequences rapid movements and timing? Lesion? Inputs? Outputs?

Cerebro (ponto) cerebellum!

Lesion: Dysdiadokinesia

Input: cortex --> dentate nucleus via thalamus

Output: back to thalamus via premotor nucleus

39

What part of the cerebellum sequences balance and eye movements? Input? output? Lesion?

Vestibulocerebellum

input: eyes and ears, vestibular nucleus

output: LMN in SC

Lesion:
balance and gait issues

40

What NTs do the cerebellum fibers use?

Mossy:
Climbing:
Purkinje

Mossy: Glutamate
Climbing: aspartate
Purkinje: GABA

41

Name Walking or Arm/Hand:

CPG in spinal cord?
Sensory input is crucial?
Comes from Cerebellum, basal ganglia?
Derived from cortex?

Walking

Arm hand

Arm hand

Walking

42

The straitum is stimulated from what?

Substantia nigra w/ glutamate and motor corte. via glutamate

43

What happens if you lesion the substantia nigra pars compacta?

Parkinson tremors, slowness, rigidity

44

The Striatonigral path is from what to what with what NT?

Straitum to GPi or SNpr
with GABA

45

A pt presents with Sx of huntington's disease. in order to Dx you can do a CT and look at what part of teh brain? What NT?

B/n the straitum parts, ACh.

46

What is the largest input to the striatum? Next?

Straitum outputs:

From cortex with glutamate.

From substantia nigra with dopamine


Output: inhibitory Medium spiny neurons via GABA

47

Parkinsons' can be caused by lesions of what now? (3)

nigrostriatum tracts

SNpc

Subthalamic nucleus

48

Subthalamic nucleus gets inputs from what?

outputs go to where?

inputs: frontal lobe & globus pallidius externus

Outputs: Excitatory via glutamate

49

Dopamine has 2 receptors. What are they and their fxns?

D1 - excitator the direct pathway
D2 - inhibitory. Inhibit the indirect pathway = more movement

50

IN parkinsons, which basal ganglia is continous?

Indirect pathway overactive, and direct cannot be stimulated.

51

In the taste pathway, serotonin binds to what? ATP?

Serotonin
post-gustatory complex

ATP
Post and pre-gustatory
Autocrine

52

MOA for salty?

Epithelial salt channels (ENaC) → Na crosses into cells → depolarizes it → increases intracellular Ca → serotonin released

53

MOA for sour?

H+ ions → inhibit potassium channels → depolarization → increased intracellular Ca → serotonin release

54

MOA for sweet, umami, and bitter?

Binds to GPCR → PLC-IP3 pathway → IP3R3--> increase intracellular calcium → TRPM5 activation → sodium flows in→ depolarization → ATP release via Panx1 channels → neurotransmitter release

Umami: mGLUR4
Bitter: high affinity

55

MOA for smell rceptors

Odorant binds Golf → adenylyl cyclase → ↑ cAMP → opens cyclic nucleotide gated channels CNGC → cation influx and depolarization

56

How does smell adaptation work?

CNGC loses sensitivity for cAMP

57

What ganglion are for what taste nerves? What is the pathway from these 3

VII - geniculate
IX - petrosal
X - nodose

Nucleus tractus solitarius/gustatory area --> VPM --> PLIC --> Gustatory complex (post central gyrus, frontal operculum, insular cortex)

58

What is the function of the orbitofrontal cortex?

Taste/olfaction/visual/gustatory cues

59

Pathway of smell back to brain?

Olfactory neuron release→ glutamate → glomerulus → mitral, granule, periglomerular cells → olfactory tract → olfactory cortex → all over

60

Fxns of smell cells? Mitral, granule, periglomerular?

granule and perigromlerular = Gaba
Mitral - projects to olfactory

61

Components of Olfactory cortex?

- Anterior olfactory nucleus --> Relay to cortex
- Olfactory tubercle
- Piriform complex:
--> hypothalamus --> appetite and hunger
--> thalamus --> medial orbitofrontal cortex --> taste, sight, smell
- Anterior cortical amgydaloid --> emotion and fear
- Periamygdaloid --> emotional odor
- Lateral entorhinal --> hippocampus --> memory of eating

62

Neurons or taste cells?

- Stays open at rest with fixed permeability?
- Na+ gradient fluctuates?
- Voltage dependent?
- Sodium permeability can change?

Taste,
Taste

neuron
neuron

63

A pt with migraines or psychotic states may experience what olfactory/gustatory symptom?

hyperosmia!!
Hyper smell

64

What acts on ciliary muscle to change shape of lens?

Parasympathetics make it more round
Sympathetics flatten it

65

What visual cells are vertical? Horizontal?

Vertical: rods/cones, bipolar, ganglion cells
Horizontal:
Horizontal and amacrine

66

What is the difference between on center and off centers vesides where the depolarization is?

The depolar glutamate receptors are AMPA, where as the on center ones are GPCR Gi.

AMPA --> incease Na
Gi

67

What type of cell do Rods converge on?

ON CENTER bipolar --> amacrine --> cone bipolar --> ganglion

68

What is the purpose of horizontal cells?

to repress the ganglion to sharpen the image via GABA

69

What is the function of the lateral geniculate body?

Control motions of eyes to converge, control focus based on distance, map objects in space

70

There are a bunch of layers in the primary visual cortex. What are the fxns of each?

IV and V, VIis important

I-III - networking between V1 and other parts of cortex
IV - Input
V - VI - output to Lateral Geniculate body, thalamus, subcortical regions
VI - Edges and contours of objects

71

Name the Brodman area associated with this Visual area, and the fxn of the Visual area.

V1
V2
V3a
V4
V5
S1
Parastriate Cortex?
Peristriate cortex

V1 - Brodman 17
- Primary visual cortex

V2 - Greater 18
- Depth perception

V3a = Lesser 18
- Identifies motion

V4 - 19
- Processes Color inputs

V5- 19 (Middle temporal)

S1- 3, 1, 2
- Primary Sensory Area

18 Parastriate

19 Peristriate

72

What end of hair cells is endolymph? Perilymph?

Endolymph: apical end
Perilymph: basal end.

73

Ah yes, sound waves. pathway?

*sound waves* → tympanic membrane → ossicles → oval window → Scala vestibuli pressure falls below scala tympani --> vibrates basement (basilar) membrane of cochlea→ tectorial membrane --> muscle called prestin moves the outer hair cells --> TRPA1 --> K+ influx --> depolar --> Ca --> glutamate to perilymph --> AP

74

Fxn of
Inner hair cells

Outer hair cells

Inner: primary source of auditory info

outer: Amplifier, Contractile, boosts vibrations

75

WHere do the afferent fibers come from to the hair cells?
Efferent?

Afferent - spiral ganglia

Efferent - superior olivary complex to outer

76

There is a ventral and dorsal cochlear nuclei. Difference in fxn?

Ventral - Nature of sound, high or low
Dorsal - lcoation of sound. localizes

77

There is a medial and lateral superior olivary nuclei, different fxns?

Medial SO - Interaural time difference via glutamate

lateral SO - intensity differences also help localize

78

Inferior colliculi fxn?

Suppresses echo information to spatially map sounds

79

What is the general pathway of sound wave data?

Cochlear nuclei --> Superior Olivary Nucleus --> Inferior colliculi --> Superior Colliculi --> Medial Geniculate

80

Difference between primary auditory complex and associated auditory cortical areas?

A1 - yes sound! volume, rate, loudness!

Association: Music and more complex stuff

81

What can protect the ear from loud noises?

OCN (olivocochlear nucleus)
Tensor tympani V and stapedius VII; prevents low frquency damage

82

What are otoacoustic emissions?

sensorineural hearing loss?

Otoacoustic: Ears producing sound via motile outer hair cells (hear loss testing)

Sensorineural: damage to hair fibers and nerve, usually OHC damage

83

Cerebellum has a big part in vestibular activities.

Describe what is stimulated when a person is:
spinning
Falling back
falling forward

Suppresses optic reflexes to allow for voluntary motion.

Spinning: Horizontal semicircular canals --> medial rectus activated, lateral rectus inhibited, oppo on other eye

Fall back: posterior semicircular canal --> superior oblique activated, inferior oblique inhibited
Falling forward --> anterior semicircular canal --> superior rectus and inferior rectus muscle inhibited.

84

WHat are 2 insular cortex fxns?

interpretation of pain
gustatory complex

85

Each part of the Central Nervous System has reactions. Name these reflexes for where they lie (cortex, brainstem, spinal reflexes):

Eye/Head movements?
Hopping Reflex?
Suckle?
DTR?
GTO?
Vestibular?
Yawn?

Brainstem

Corticol

Brainstem

Spinal
Spinal

Brainstem
Brainstem

86

Where exactly are GTOs located on the muscle?

Where the muscle junctions with the tendon

87

What is lost in a spinal shock?

Sensation and reflexes under the lesion

88

There are 6 layers in the cortex. 2 of which are enlarged in the primary sensory cortex. Which ones and why?

III and IV
bc the axons from the thalamus terminate there.

89

Neuronal columns organized side by side?

Side by side are totally different, only same location on body
Up and down = same same

90

2 actions of serotonergic and noradrenergic neurons:

1. Acivate local interneurons to inhibit
2. Suppress spinothalamic projections

91

What is antidromic signaling?

The efferent actions of nociceptors - Smooth muscle contraction, arteriole dilation, mast cell degranulation
(Inflammation)
Also cause of referred pain

92

What makes up gustatory complex?

(post central gyrus, frontal operculum, insular cortex)

93

What 2 places can neurogenesis occur?

Olfactory and dentate gyrus of hippocampus

94

Which part of the cerebellum can sense future movements and make changes for that?

Spinocerebellum

95

What is the function of basal ganglia?

PLanning and programming,
(Somehwere in initiaiton)

96

Difference between SNpr and SNpc?

SNpc receives inputs
- relays to striatum via nigrostriatal path (dopamine)

SNpr is the output
Out usually to inhibit thalamus (GABA)

97

Which basal ganglia receives most of the input?
Where does input come from?
How does it talk to other basal ganglia?
How does it talk to itself?

Straitum
Cortex via glutamate
SNpc via dopamine

Output is inhibitory via medium spiny neurons GABA.

Self: intrastriatal: cholinergic, stimulatory

98

Which basal ganglia receives all the input from the frontal lobe?
How does it talk to other basal ganglia?

Subhtalamic nucleus

Excitatory via glutamate

99

corticostriatum what does it release?
What is released from nigrostriatal tract?

EAA

SN --> striatum dopamine

100

What is the effect of the loss of dopamine in Parkinson's pts? Where does this dopamine come from?

Comes from SNpc

The thalamus direct and indirect pathways.
If no Dopamine binding to D2 to inhibit the inhibitory pathway, then pt has trouble starting the movement.
If no dopamine binding to D1 to excite the direct pathway, also trouble starting movement. ( can still be stimulated by cortex via glutamate)

101

What is the path of light to the RPE?

Cornea
Lens
Vitreous fluid
Ganglion cell
Bipolar cells
Rods cons
RPE -->

102

Where does the retina send information to? (6)

LGB
Superior Colliculus
Pretectum
Hypothalamus
Accessory optic nuclei
Pulvinar thalamus

103

Of the targets that the retina sends information to, which is in charge ofthe:
- pupillary light reflex?
- Circadian Rhythms and light-dark entrainment?
- Advanced visual processsing?
- Controls accommodation, distance vision and positions of objects?
- Saccadic movement (simultaneous movement of both eyes)

Pretectum

Hypothalamus

Accessory optic nuclei

Lateral Geniculate body

Superior colliculus

104

What part of the brain allows you to recognize faces and name objects?

Ventral pathway, "What" from V1 to the inferior temporal cortex

105

Indirect pathway of basal ganglia, go!

Direct pathway, Go!

What happens in Parkinson's?

Striatum (GABA) --> GPe (GABA) --> STN (glutamate) --> Gi (GABA) -->Thalamus --> movement

Cortex (glutamate) --> Striatum (Gaba) SNpr & GPi (Gaba) --> Thalamus --> movement

106

Which semicircular canal activates the oblique eye muscles?
Rectus muscles?

posterior semicircular canals

Anterior semicircular canal

107

Where do taste and olfactory first integrate?

Nucleus Tractus Solitarius

108

Cross talk between hypothalamus and cortex in the gustatory

Interpret hunger and appetite

109

A sign change is used on what receptor?

GPCR

110

Difference between the PTO and the medial orbitofrontal complex?

PTO --> Cortical processing, somatosensory, hearing, vision

MOF --> Integration of visual, somatosensory, olfactory, gustatory

111

Where is the Cl- influx tract located?

Pre-synaptic inhibition

112

What autonomic receptors have the same function and intracellular stuff?

HAV1 M&M --> Smooth muscle contraction via Phospholipase C

MAD 2s --> Gi (adenylyl cyclase)

113

What releases glycine in what pathway?

Gate control theory, the inhibitory interneuron releases glycine after being stimulated by the Ab with glutamate

114

What FIBERS recept heat? Cold?

Heat: C fibers
Cold: C fiber sand alpha delta

115

In a Parkinson's pt, what are the concentrations of:
ACh
Gaba
Dopamine

Ach is increased
GABA is decreased
Dopamine is decreased.

116

TRPM5 is found where?

SUB taste pathways

117

Hair cells are rich in what protein?

Actin

118

Depolarization in a hair cell stimulates 2 paths.

Scala media

119

Fxn of superior colliculus?

Vertical height to sound

120

Fxn of medial geniculate body?

Processes speech inflections

121

Which olivocochlear efferent innervates what hair cells?

Medial = outer

Lateral = inner

122

What lymph is inside the vestibular apparatus? What is tin the bony?

Endolymph Perilymph