Chapter 41: Somatosensory Cortex Flashcards Preview

Neuroanatomy > Chapter 41: Somatosensory Cortex > Flashcards

Flashcards in Chapter 41: Somatosensory Cortex Deck (69)
Loading flashcards...
1
Q

The central sulcus is between the _____ gyrus and the _____ gyrus.

A
  • Precentral

- Postcentral

2
Q

The precentral gyrus is on the posterior (caudal) edge of the _____ lobe.

A
  • Frontal
3
Q

The postcentral gyrus is on the anterior (rostral) edge of the _____ lobe.

A
  • Parietal
4
Q

The ventroposterolateral and ventroposteromedial nuclei of the _____ project to the primary somatosensory cortex in the _____ gyrus of the parietal lobe.

A
  • Thalamus

- Postcentral

5
Q

Brodmann divided the _____ into 3 vertical strips, numbered 3, 1, and 2 from the central sulcus to the postcentral sulcus.

A
  • Postcentral gyrus
6
Q

Area _____ is posterior to area 1, but area _____ is anterior to area 1.

A
  • 2

- 3

7
Q

The anterior to posterior sequence of Brodmann areas in the postcentral gyrus is _____, _____, _____.

A
  • 3
  • 2
  • 1
8
Q

Brodmann’s area 1, forming the central strip of the _____, receives discriminative touch sensations from area 3 anterior to it.

A
  • Postcentral gyrus
9
Q

Area 3 sends discriminative touch sensations to _____.

A
  • Area 1
10
Q

Area _____ infers texture from discriminative touch sensations.

A
  • 1
11
Q

Area 1 is only the _____ strip of the _____.

A
  • Central

- Postcentral gyrus

12
Q

Area 3 is _____ to area 1, mostly on the posterior wall of the central sulcus.

A
  • Anterior
13
Q

Posterior to area 1, area _____ receives pressure and tendon stretch sensation from area 3.

A
  • 2
14
Q

Area _____ infers size and shape from tendon stretch.

A
  • 2
15
Q

Injury to area 3 or area 2 causes astereognosis, the inability to recognize _____ and _____ with the eyes closed.

A
  • Size

- Shape

16
Q

Area _____ infers weight from tendon stretch and pressure.

A
  • 2
17
Q

Area 3 receives epicritic information from the _____ and _____ of the _____ and sends discriminative touch to area _____ and tendon stretch and pressure to area _____.

A
  • VPL
  • VPM
  • Thalamus
  • 1
  • 2
18
Q

Epicritic sensation is somatotopically arranged in areas _____, _____, and _____ on a map that parallels the somatopic map of the primary motor cortex on area 4.

A
  • 3
  • 2
  • 1
19
Q

Because the spinothalamic fibers cross in the _____ of the _____ and the medial lemnisci cross in the _____, the somatosensory cortex is concerned with the _____ side of the body.

A
  • Anterior white commissure
  • Spinal cord
  • Medulla
  • Contralateral
20
Q

Brodmann area 5 is a small region in the posterior wall of the _____ sulcus and the adjacent _____ cortex posterior to the somatosensory cortex for the trunk, arm, and hand.

A
  • Postcentral

- Parietal

21
Q

Brodmann area 5 receives information about tendon stretch in the hand from area _____ and the neurons in the _____ of the thalamus that receive tendon stretch information about the hand.

A
  • 2

- VPL

22
Q

Area 5 projects to area 4 to assist in reaching and grasping movements of the _____.

A
  • Hand
23
Q

Although it is a sensory area, area _____ guides motor activity of the hand and arm through its projections to area 4 and its projections to internuncial neurons influencing lower motor neurons.

A
  • 5
24
Q

Some axons from neurons in area 5 project to the anterior horn of the spinal cord via the _____ tracts.

A
  • Corticospinal
25
Q

Like lesions of the _____, lesions in area 5 cause past-pointing, but they do not cause resolution of movement.

A
  • Cerebellum (or pontocerebellum)
26
Q

Like lesions of area _____ or _____, lesions of area 5 cause astereognosis.

A
  • 3

- 2

27
Q

Astereognosis is the inability to recognize _____ and _____ with the _____ closed.

A
  • Size
  • Shape
  • Eyes
28
Q

Area _____ is sometimes called the “hand manipulation area.”

A
  • 5
29
Q

Brodmann areas 1, 2, and 3 occupy the visible part of the _____ gyrus and its sidewalls.

A
  • Postcentral
30
Q

The _____ gyrus is often called the primary somatosensory cortex (S I).

A
  • Postcentral
31
Q

Discriminative touch, pressure, and tendon stretch reach consciousness in the _____ cortex.

A
  • Primary somatosensory
32
Q

Conscious proprioception is localized in the _____ cortex on the postcentral gyrus.

A
  • Primary somatosensory
33
Q

The _____ and _____ nuclei of the _____ project pain to Brodmann area 3 with the same somatotopic distribution as the epicritic sensations.

A
  • Ventroposterolateral
  • Ventroposteromedial
  • Thalamus
34
Q

Brodmann area 3 projects pain to Brodmann area 1 with the same somatotopic distribution as the epicritic sensations of _____ and _____.

A
  • Touch

- Pressure

35
Q

Pain is somatotopically distributed in both Brodmann area _____ and Brodmann area _____.

A
  • 3

- 1

36
Q

Brodmann area 1 is conscious of the _____ of pain but not of its intensity.

A
  • Location
37
Q

Pain is projected _____ from VPL and VPM to Brodmann area 3 to area 1.

A
  • Somatotopically
38
Q

The lateral fissure is the inferior boundary of the _____ cortex.

A
  • Primary somatosensory
39
Q

Somatosensory cortex extends onto the roof of the lateral fissure as the secondary _____ cortex (S II) which receives independent projections of pain from the VPL and VPM.

A
  • Somatosensory
40
Q

The _____ and _____ project pain onto a head to toe map extending from lateral to medial on
the _____ of the _____ just inferior to the postcentral gyrus.

A
  • VPM
  • VPL
  • Roof
  • Lateral fissure
41
Q

Since protopathic sensations are localized from medial to lateral in the primary somatosensory cortex, the localization of _____ in the secondary somatosensory cortex is a mirror image of the map of the primary somatosensory cortex.

A
  • Pain
42
Q

One can draw a homunculus showing the localization of _____ in the secondary somatosensory cortex with its _____ in the depths of the fissure and its head next to the opening of the fissure.

A
  • Pain

- Head

43
Q

The head and throat areas of the primary and secondary somatosensory cortices meet where the _____ gyrus meets the _____ fissure.

A
  • Postcentral

- Lateral

44
Q

Because the secondary somatosensory cortex is much smaller than the _____, it localizes pain less precisely than the primary somatosensory cortex.

A
  • Primary somatosensory cortex
45
Q

The primary somatosensory cortex perceives the _____ of _____, but the intensity of pain is perceived in the secondary somatosensory cortex.

A
  • Location
46
Q

The secondary somatosensory cortex communicates the _____ of pain to the posterior insula and the contralateral secondary somatosensory cortex.

A
  • Intensity
47
Q

Pain is projected from both secondary somatosensory cortices to the posterior halves of both _____.

A
  • Insulas
48
Q

The _____ of pain is perceived unilaterally, but the _____ of pain is perceived bilaterally.

A
  • Location

- Intensity

49
Q

The posterior half of each _____ projects to the cortex of the ipsilateral anterior cingulate gyrus (Brodmann areas 24 and 32).

A
  • Insula
50
Q

The cingulate gyrus is part of the _____ system.

A
  • Limbic
51
Q

As part of the limbic system, _____ is responsible for most of the emotional component of pain.

A
  • Anterior cingulate gyrus
52
Q

The ventroposterolateral thalamus and ventroposteromedial thalamus send pain messages to the _____ cortex which records their intensity.

A
  • Secondary somatosensory
53
Q

The secondary somatosensory cortex sends pain messages to the contralateral _____ via the corpus callosum.

A
  • Secondary somatosensory cortex
54
Q

Each secondary somatosensory cortex sends pain messages to the posterior half of the ipsilateral _____.

A
  • Insula
55
Q

Each insula sends pain messages to the _____, which is responsible for most of the emotional aspect of pain.

A
  • Anterior cingulate gyrus
56
Q

Itching is projected from the _____ nucleus of the _____ to the secondary somatosensory cortex.

A
  • Ventral posterior inferior

- Thalamus

57
Q

Because it is projected only to the _____, itch is less well localized than pain.

A
  • Secondary somatosensory cortex
58
Q

The somatotopic arrangement of the primary somatosensory cortex on the _____ gyrus parallels the somatotopic arrangement of the _____ on the _____ gyrus.

A
  • Postcentral
  • Primary motor cortex
  • Precentral
59
Q

The secondary somatosensory cortex is somatotopically arranged on the _____ of the _____ with the _____ region in the depth of the fissure and the _____ region on the lateral edge.

A
  • Roof
  • Lateral fissure
  • Foot
  • Head
60
Q

The _____ and _____ of the _____ project sensations from the _____ side of the body to both the primary and secondary somatosensory cortex.

A
  • VPL
  • VPM
  • Thalamus
  • Contralateral
61
Q

The primary sensory cortex perceives the _____ of pain, but the secondary cortex perceives its _____.

A
  • Location

- Intensity

62
Q

Pain becomes suffering when the _____ sensory cortex projects it to the _____ half of the _____ which projects it to the _____ half of the _____.

A
  • Secondary
  • Posterior
  • Insula
  • Anterior
  • Cingulate gyrus
63
Q

Discriminative touch is appreciated in area _____ in the _____ of the postcentral gyrus.

A
  • 1

- Center

64
Q

Tendon stretch and pressure are appreciated in area _____ on the _____ edge of the _____ gyrus.

A
  • 2
  • Posterior
  • Postcentral
65
Q

Brodmann area 5 is the _____ which is _____ to the dorsal third of the _____ sensory cortex.

A
  • Hand manipulation area
  • Posterior
  • Primary
66
Q

Area 5 receives _____ information from the _____ and projects to the _____ guide movements of the _____ hand.

A
  • Proprioceptive
  • Primary sensory cortex
  • Primary motor cortex
  • Contralateral
67
Q

The hand manipulation area projects to the primary motor cortex and to the _____ of the _____.

A
  • Anterior horn

- Spinal cord

68
Q

Two thirds of the corticospinal fibers come from the _____ and _____ cortex in the _____ lobe; one third come from the parietal lobe.

A
  • Motor
  • Premotor
  • Frontal
69
Q

One third of the cortical projections to the internuncials of lower motor neurons are projections from the _____ cortex that help to guide actions.

A
  • Parietal