thalamus & somatosensory cortex

Question 1

what part of the thalamus receives sensory information from the body

Answer 1

ventral posterior lateral (VPL) nucleus

Question 2

what part of the thalamus receives sensory information from the head

Answer 2

ventral posterior medial (VPM) nucleus

Question 3

internal capsule

Answer 3

densely packed fiber region where all sensory and motor info pass (corona radiata)

Question 4

blood supply to internal capsule via?

Answer 4

cerebral artery

Question 5

cerebral artery damage

Answer 5

• eliminate blood supply to internal capsule

- transfer of motor & sensory signals would cease causing fatal injury

Question 6

primary somatosensory cortex

Answer 6

S1

Question 7

primary somatosensory cortex location

Answer 7

postcentral gyrus of parietal lobe

Question 8

primary somatosensory cortex brodmann’s area (BA)

Answer 8

1, 2, 3a, 3b

- four regions/fields total

Question 9

primary somatosensory cortex columnar organization

Answer 9

• each BA corresponds to a submodality like 3a (proprioception) and 3b (tactile)
• each BA contains separate and complete representation of the body

Question 10

primary somatosensory cortex projections

Answer 10

input from VPL & VPM of the thalamus project into layer 4

Question 11

layers 1-6 of cortex

Answer 11

2&3 - motor
4 - sensory enters
5 - sensory leaves

Question 12

secondary somatosensory cortex

Answer 12

S2

Question 13

secondary somatosensory cortex location

Answer 13

upper bank of the lateral sulcus

Question 14

secondary somatosensory cortex columnar organization

Answer 14

• “higher order” cortical field

- receives convergent projections from all subdivisions of S1

Question 15

secondary somatosensory cortex projections

Answer 15

limbic structures: amygdala & hippocampus

Question 16

sensory homunulus

Answer 16

• schematic showing parts of body where the size of each part indicates how many neurons are innervating that particular part
• hands and face are largest! (higher # sensory receptors)

Question 17

primary somatosensory cortex functional columns

Answer 17

within single cortical areas, neurons with similar response properties (receive input from slowly vs. rapidly adapting receptors) are clustered together into functionally distinct columns that transverse the depth of the cortex

Question 18

somatic sensory cortex plasticity

Answer 18

repetitive behavioral task expands the region of the cortex that contains neurons activated by this task