Brainscape's Knowledge GenomeTM

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


See full index

Year 1: 06. Neuro Exam 2 > Lecture 9: Somatosensory Pathways Part 1 > Flashcards

Lecture 9: Somatosensory Pathways Part 1 Flashcards

1
Q

What information does the PCML and trigeminothalamic pathway transmit?

A

Discriminative Touch
Pressure
Vibration
Proprioception

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

What is two point discrimination?

A

Ability to discriminate between two stimuli simultaneously

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

What areas would have high density of tactile receptors?

A

Digits

Perioral region

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

What areas would have low density of tactile receptors?

A

Back

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

Small receptive fields have ____ receptor density.

Large receptive fields have ____ receptor density.

A

Small receptive fields have HIGH receptor density.

Large receptive fields have LOW receptor density.

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

What type of axons are primary afferent fibers?

A

Sensory

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

Where do primary afferent fibers have their cell bodies?

A

Dorsal Root Ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In the PCML pathway, where do primary afferent fibers enter the spinal cord?

A

Medial division of posterior root

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

In the PCML pathway, where do primary afferent fibers go after entering the spinal cord?

A

Posterior Columns: Fasciculus Gracilis and Cuneatus

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

Where is Fasciculus Gracilis found?

A

Sacral Region to T6

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

Where is Fasciculus Cuneatus found?

A

T6 and above

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

Which fibers are found more medially?

A

Sacral and the more rostral you go, the more lateral those fibers are found

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

What supplies the posterior columns?

A

Posterior Spinal Artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

If the PCML pathway is affected from a spinal cord lesion, what can happen?

A

Ipsilateral reduction or loss of discriminative, positional, and vibratory tactile sensations
Will happen at and below level of injury

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

What is sensory ataxia?

A

Loss of muscle tendon reflex and proprioceptive losses from extremities due to lack of sensory input
Can lead to difficulty walking and wide based stance

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

In the PCML pathway, where are 2nd order neurons found?

A

Gracile and Cuneate Nuclei in the posterior medulla

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

Where are the gracile and cuneate nuclei receiving their input from?

A

First order neurons (primary afferents) from ipsilateral dorsal root ganglion

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

What are internal arcuate fibers?

A

After synapsing at the gracile and cuneate nuclei, they are the fibers that cross anteromedially in the medulla

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

What is medial lemniscus?

A

The new name of the fibers after they cross at the medulla until they terminate

20
Q

In the medial lemniscus, where do the upper and lower extremity fibers now reside after the rotation in the pons?

A

Upper: Medial
Lower: Lateral

21
Q

Where does the medial lemniscus terminate?

A

Ventral Posterolateral Nucleus of the Thalamus

22
Q

What supplies the medial lemniscus?

A

Anterior Spinal Artery

23
Q

What supplies the Ventral Posterolateral Nucleus of the Thalamus?

A

Thalamogeniculate Branches of Posterior Cerebral Artery

24
Q

From the Ventral Posterolateral Nucleus of the Thalamus, where do the third order neurons go to?

A

Primary and Secondary Somatosensory Cortices

25
Q

How do third third order neurons reach the somatosensory cortices?

A

Via Posterior Limb of Internal Capsule

26
Q

What compromises the Primary Somatosensory Cortex (S1)?

A

Postcentral gyrus and Posterior Paracentral Gyrus

27
Q

What are the Brodmann Areas of the Primary Somatosensory Cortex?

A

31, 3b, 1, and 2

28
Q

If there is a lesion to the Middle Cerebral Artery, where would there be tactile loss?

A

Contralateral upper body and face

29
Q

If there is a lesion to the Anterior Cerebral Artery, where would there be tactile loss?

A

Contralateral lower limb

30
Q

What does the secondary somatosensory cortex sense?

A

Inner face

31
Q

Where does secondary somatosensory cortex gets its input from?

A

Ipsilateral SI cortex and Ventral Posterior Inferior Nucleus of the Thalamus

32
Q

What happens if the parietal cortical region is lesioned?

A

Agnosia: cannot recognize own limb

33
Q

What is the role the mesencephalic nucleus?

A

Conveys unconscious proprioceptive afferents and pressure afferents from TMJ, masticatory, and extraocular muscles

34
Q

What is the role the principal/chief sensory nucleus?

A

Discriminative touch and pressure from face

35
Q

What is the role the spinal nucleus?

A

Pain, temperature, and non-discriminative touch from face

36
Q

In the Sensory Trigeminothalamic Pathway, where are primary afferents from?

A

Trigeminal Ganglion

37
Q

In the Sensory Trigeminothalamic Pathway, where are 2nd order neurons found?

A

Principal/Chief Sensory Nucleus

38
Q

What supplies the Principal/Chief Sensory Nucleus?

A

Superior Cerebellar Artery

Long Circumferential branches of Basilar Artery

39
Q

What are the two divisions of the principal/chief sensory nucleus and what do they receive information from?

A

Dorsomedial: Oral Cavity
Ventrolateral: V1, V2, V3

40
Q

How does the dorsomedial division reach the thalamus?

A

Travels ipsilaterally via posterior trigeminothalamic tract to

41
Q

How does the ventrolateral division reach the thalamus?

A

Travels contralaterally via anterior trigeminothalamic tract

42
Q

Where do both anterior and posterior trigeminothalamic tracts synapse at?

A

Ventral Posteromedial Nucleus of the Thalamus

  • Oral Cavity: Medial part of nucleus
  • External Face: Lateral part of nucleus
43
Q

From the Ventral Posteromedial Nucleus of the Thalamus, where do the third order neurons go to?

A

Primary somatosensory nucleus via posterior limb of internal capsule

44
Q

What reflex is initiated when there is a downward tap on the chin?

A

Jaw-Jaw Reflex: Stretching of masseter muscle causes it to contract bilaterally

45
Q

What is the pathway of a jaw-jaw reflex?

A
  1. Innervation of Mesencephalic Trigeminal Neuron
  2. Innervation of masseter muscle spindle
  3. Synapse on trigeminal motor neuron

Year 1: 06. Neuro Exam 2 (28 decks)

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