Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

VET 404: Neurology > Sensory Systems > Flashcards

Sensory Systems Flashcards

1
Q

types of sensation

A
  1. special
  2. somatosensory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

pathway of sensory info

A
  1. sensory afferent
  2. dorsal root ganglia
  3. spinal cord
  4. reflex arc OR ascending pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do receptors do

A

change energy into electrical activity (action potential) that changes the membrane potential to signal to the next neuron in the pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

receptor modalities

A

mechanoreceptors
thermoreceptors
electromagnetic
chemoreceptors
nociceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

receptor categories

A

exteroceptors
interoceptors
proprioceptors
nociceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

stimulus

A

results in a change in receptor potential

if exceeds threshold, will cause an AP to be generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ways to classify stimuli

A
  1. modality
  2. intensity
  3. duration
  4. location
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

temporal summation

A

increased frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

spatial summation

A

increased number of nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

adaptation

A

slower rate of AP firing with continued stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

phasic receptors

A

rapid; detect changes in stimuli and inform about its rate of change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

tonic receptors

A

slow; detect continuous stimuli and informs about its presence and strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

three sensory system

A
  1. medial lemniscal system
  2. ascending reticular formation
  3. spinocerebellar tracts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

conscious proprioception

A

proprioceptive information sent to the contralateral cerebrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

subconscious proprioception

A

proprioceptive information sent to the ipsilateral cerebrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

function of the cerebellum

A

mediates coordinated movement; requires:
- proprioceptors
- vestibular system
- motor system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

proprioceptive mechanoreceptors

A

provide information about the effects of gravity on muscles and the differences between actual and intended movements

located in the head (vestibular system) and limbs (joints, muscles, skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

muscle spindle

A

fibers in skeletal muscle that detects changes in length (stretch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

intrafusal fibers

A

SMALL fibers located within a spindle shaped collagen capsule that runs in parallel with extrafusal fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are intrafusal fibers innervated by

A

1a afferent neurons
y efferent neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

function of intrafusal fibers

A

sense proprioception
chain fibers: detect static muscle length
bag fibers: detect dynamic muscle length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

extrafusal fibers

A

LARGE standard muscle fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are extrafusal fibers innervated by

A

alpha motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

muscle spindle reflex

A

“stretch” reflex

monosynaptic reflex in response to muscle stretch; signals to motor neurons (that innervate the same muscle) to fire, causing contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

pathway of muscle spindle reflex

A
  1. intrafusal fiber stretches
  2. 1a afferent carries signal to DRG
  3. 1a afferent synapses onto the alpha motor neuron
  4. alpha motor neuron transmits signal to the extrafusal muscle fibers
  5. extrafusal fibers contract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

function of muscle spindle reflex

A

“smooth” and stabilize movement and posture/muscle tone
- antagonizes the stretch of one muscle as a feedback mechanism to prevent over stretching
- constantly activated while moving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

central excitatory state

A

the status of output of the nervous system
- determined by gamma motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

gamma motor neurons

A

located on the ends of muscles; tonically fires to increase the muscle’s sensitivity to stretch, which activates alpha motor neurons to fire and contract extrafusal fibers

29
Q

high gamma bias

A

excitatory state; gamma neurons fire more frequently –> increases sensitivity to stretch in order to keep muscles ready to contract quickly

30
Q

low gamma bias

A

relaxed state; gamma neurons fire less frequently –> decreased muscle sensitivity to stretch

31
Q

what are the two ways that muscle spindles can cause extrafusal fiber contraction

A
  1. mechanical stretching of extra/intrafusal fibers
  2. firing on gamma motor neurons during voluntary movement
32
Q

Golgi tendon organ

A

located in the tendon; connected in series with muscle fibers

detects changes in tension by deforming with contraction/stretch

33
Q

GTO reflex

A

disynaptic reflex in response to too much tension on a muscle

tension initiates an inhibitory pathway that prevents the muscle from contracting OR stimulates antagonizing muscles to contract

34
Q

function of GTO reflex

A

“smooths” movement; protects muscle from excess tension

35
Q

GTO reflex pathway

A

tension –> 1b afferent –> inhibitory interneuron –> inhibits activity of efferent –> inhibits contraction

36
Q

large diameter fibers

A

fast, myelinated fibers in the spinal cord

transmit information about touch, pressure, and proprioception

37
Q

small diameter fibers

A

slow, unmyelinated fibers in the spinal cord

transmit information about nociception and temperature

38
Q

thalamus

A

receives all sensory input (except olfaction) and relays to specific cortical areas

39
Q

specific relay from thalamus

A

somatotopic projections from thalamus to cortex

40
Q

diffuse projection from thalamus

A

widespread projections from the thalamus that go to various areas of the cortex

41
Q

thalamo-cortical pathways

A

white matter tracts between thalamus and cortex

corona radiate and internal capsule

42
Q

dorsal column-medial lemniscal pathway (DC-ML)

A

large, fast, myelinated axons that transmit MECHANORECEPTION and CONSCIOUS PROPRIOCEPTION to the cerebrum

43
Q

medial lemniscus

A

bundle of thick, myelinated, ascending axons that decussate in the brainstem

44
Q

long tracts

A

extend from DRG all the way up the spine without an interneuron

45
Q

what are the two types of long tracts

A
  1. gracile tract
  2. cuneate tract
46
Q

gracile tract

A

located in the medial dorsal funiculus

receives information from the caudal half of the body

47
Q

cuneate tract

A

located in the lateral dorsal funiculus

receives information from the cranial half of the body

48
Q

dorsal column nuclei

A

nuclei located at the obex

  1. gracile nucleus
  2. cuneate nucleus
49
Q

gracile nucleus

A

contains secondary neurons that synapse with primary neurons from gracile tract

50
Q

cuneate nucleus

A

contains secondary neurons that synapse with primary neurons from cuneate tract

51
Q

ventro-caudo-lateral nucleus

A

located in the thalamus

site of secondary neuron synapse onto tertiary neurons

52
Q

DC-ML pathway

A

3 neuron pathway

  1. primary neurons reach spinal cord and enter at ipsilateral dorsal funiculus
  2. primary neurons extend up gracile/cuneate tracts to the dorsal column nuclei
  3. primary neurons synapse with secondary neurons in dorsal column nuclei
  4. secondary neurons decussate the to contralateral side of the brain into the medial lemniscus
  5. secondary neurons extend through brainstem to ventro-caudo-lateral nuclei in the thalamus where they synapse onto tertiary neurons
  6. tertiary neurons extend to the appropriate primary somatosensory cortex in the cerebrum
53
Q

where do secondary motor neurons of DC-ML pathway synapse within ventro-caudo-lateral nuclei

A

if from cranial 1/2 of body: medial

if from caudal 1/2 of body: lateral

because of decussation of fibers between spinal cord and thalamus

54
Q

function of the spinomedullothalamic pathway

A

provides position sense for the pelvic limbs
- conscious proprioception

55
Q

function of the spinocervicothalamic pathway

A

responds to mechanical, thermal, and noxious stimuli
- no proprioception
- only present in carnivores/domestic animals

56
Q

spinomedullothalamic & spinocervicothalamic pathways

A
  1. primary neuron reaches spinal cord and enters at ipsilateral lateral funiculus
  2. primary neuron synapses onto an interneuron located in the dorsal horn
  3. interneuron extends up to nuclei in the medulla
  4. continues the same as DC-ML pathway
57
Q

reticular formation

A

primitive midline system; diffuse network that receives input from cerebrum, cerebellum, and spinal cord

involved in “true” pain perception - NOT pinprick pain

58
Q

reticular activating system (RAS)

A

functions in activating the cerebral cortex

input: collaterals from all sensory tracts on the way to thalamus

output: diffuse (NOT somatotopic) to thalamus and cortex; some descending pathways

59
Q

function of ascending reticular system

A

sets the level of consciousness of the cerebrum (mentation)

60
Q

signs of RAS dysfunction

A

pacing/circling, changes in mentation, compulsive walking

may have normal reflexes

61
Q

organization of brainstem pathways

A

dorsal: somatic and visceral efferents

ventral: somatic, visceral, and special visceral efferents

somatic: lateral
visceral: medial

62
Q

sensory nucleus of trigeminal

A

somatic afferent nucleus; a continuous, elongated region of gray matter in the brainstem that carries sensory info from CN V

63
Q

motor neuron V

A

carries motor information from CN V out of the brainstem

64
Q

CN V sensory pathway

A
  1. primary afferent enters trigeminal ganglion in the skull
  2. primary afferent enters trigeminal nerve to enter the brainstem at the level of the pons
  3. primary afferent descends down the medulla along the spinal tract of CN V to the sensory nucleus of trigeminal nerve, where it synapses with the secondary afferent neuron
  4. secondary afferent decussates to the contralateral side of the brainstem and ascends to the ventro-caudo-lateral nucleus of the thalamus (along the trigemino-thalamic pathway)
  5. secondary afferent synapses with tertiary afferent in the thalamus and extends to the head/face areas of the somatosensory cortex
65
Q

nucleus of solitary tract

A

visceral afferent nucleus; a continuous, elongated region of gray matter within the brainstem that carries sensory info for taste sensation

66
Q

sensory pathway for taste

A
  1. primary afferent neurons enter respective ganglia (CN VII, CN IX, X), then enter the brainstem
  2. primary afferent neurons synapse with secondary afferents at the nucleus of solitary tract
  3. secondary neurons ascend both ipsilaterally (most) and contralaterally along the nucleus to a ventral group of nuclei in the thalamus
  4. secondary afferents synapse with tertiary afferents in the thalamus, which project to the cortex
67
Q

what CNs does the salivary reflex test

A

afferent: CN IX
efferent: CN IX

68
Q

what CNs does the gag reflex test

A

afferent: CN IX, CN X, CN V
efferent: CN XI, CN XII

VET 404: Neurology (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions