Thalamus

Question 1

parts of the diencephalon

Answer 1

• thalamus
• subthalamus
• hypothalamus
• epithalamus

Question 2

internal capsule fibers

Answer 2

• brings output of cortex to subcortical sites (to LMNs)

- carries all projections from thalamus to cortex via posterior limb (except for optic)

Question 3

all sensory systems but ________ system project to the thalamus and synapse there

Answer 3

all sensory systems but OLFACTORY system project to the thalamus and synapse there

Question 4

thalamus receives motor input from ________ and _________, which is then projected to areas of primary and associated motor cortex

Answer 4

thalamus receives motor input from the CEREBELLUM and BASAL GANGLIA, which is then projected to areas of primary and associated motor cortex

Question 5

thalamus receives input from:

Answer 5

• all sensory but olfactory
• cerebellum
• basal ganglia
• limbic system
• parietal, occipital, temporal cortex

Question 6

subdivisions of the thalamus

Answer 6

• anterior
• medial
• lateral
• posterior

Question 7

thalamic nuclei

Answer 7

• medial geniculate body
• lateral geniculate body
• VPL (ventroposterolateral)
• VPM (ventroposteromedial)
• VA (ventral anterior)
• VL (ventrolateral)
• anterior
• dorsomedial
• pulvinar

Question 8

medial geniculate body

Answer 8

inf. colliculus –> medial geniculate –> Heschl’s gyrus (A1)

Question 9

lateral geniculate body

Answer 9

optic tract –> lateral geniculate –> visual cortex (V1)

Question 10

VPL

Answer 10

somatosensory pathways (STT, dorsal column)
-sensory info from BODY

STT/DC –> VPL –> sensory cortex

Question 11

VPM

Answer 11

somatosensory pathways (trigeminothalamic tract)
-sensory info from FACE

trigemial (all) –> VPM –> lower end of sensory cortex

Question 12

somatosensory nuclei of thalamus

Answer 12

• VPL

- VPM

Question 13

motor nuclei of thalamus

Answer 13

• VA

- VL

Question 14

VA

Answer 14

• motor system
• basal ganglia

globus pallidus –> VA –> motor, motor association

Question 15

VL

Answer 15

• motor system
• cerebellum

deep nuclei –> VL –> motor, motor association

Question 16

limbic system

Answer 16

-memory, emotion

Question 17

papez circuit

Answer 17

-limbic system

mamillary bodies –> anterior –> cingulate gyrus hippocampus –> mamillary bodies

Question 18

anterior nucleus

Answer 18

• limbic system
• papez circuit

mamillary bodies –> anterior –> cingulate gyrus hippocampus –> mamillary bodies

Question 19

association nuclei

Answer 19

• dorsomedial
• pulvinar

project to association cortex

Question 20

DM

Answer 20

-dorsomedial

amygdala –> DM –> frontal

Question 21

Pulvinar

Answer 21

T/P/O –> Pulvinar –> T/P/O cortices

Question 22

function of the thalamus

Answer 22

modulation of signals before they enter the cortex

–allows for selective attention

Question 23

pure sensory stroke of thalamus

Answer 23

• lacunae in VPL, VPM
• –loss of all sensation in body/face
• infarct due to small vessel disease
• associated with hypertension, DM

typified by:

• microatheroma
• lipohyalinosis

Question 24

microatheroma

Answer 24

• deposit or degenerative accumulation of lipid-containing plaques on the innermost layer of the wall of an artery
• typical of a pure sensory stroke of thalamus

Question 25

lipohyalinosis

Answer 25

- degenerative changes in small blood vessels - accumulation of glassy/waxy looking lipid in vessel wall -typical of pure sensory stroke of thalamus

Question 26

thalamic hemorrhage

Answer 26

- spontaneous intracerebral hemorrhage - associated with hypertension - involvement of adjacent internal capsule (dominates, adds hemiparesis) - also sensory involvement

Question 27

common symptoms of thalamic hemorrhage

Answer 27

- numbness, sensory deficits on CONTRAlateral side - sometimes developing into thalamic pain - hemiparesis