Thalamus

KIN 4571 Final Exam

Thalamus

• Part of the Diencephalon rostral to the brain stem that:

1. receives sensory info

2. processes sensory info

3. interprets sensory info

4. integrates sensory info with cognitive processes (ex. memory)

• gives meaning to our environment - perception

• contains many nuclei, which:

  • receive specific afferent info

  • project to specific areas in cortex

lower level

Thalamus:

• receives sensory info

• processes sensory info

higher level

Thalamus:

• interprets sensory info

• integrates sensory info with cognitive process (ex. Memory)

Thalamus

What is the green arrow pointing to?

Interthalamic adhesion

What is the red arrow pointing to?

Hypothalamus

What is the blue arrow pointing to?

Coronal

This is the _______ section through the forebrain

Corpus callosum

What is the red structure?

Subthalamic nucleus

What is the blue structure?

Substantia nigra

What is the pink structure?

Third ventricle

What is the orange structure?

Thalamus

What is the green structure?

Lateral ventricle

What is the purple structure?

horizontal

This is the _________ section through the forebrain

Putamen and Globus pallidus

What is the yellow structure?

Third ventricle

What is the orange structure?

Thalamus

What is the green structure?

Lateral ventricle

What is the purple structure?

Interthalamic adhesion

known as the “eye of the bird” since it is the dot on the Thalamus

top

The first and second (left and right lateral) ventricles are on _______ of the Thalamus

between or underneath

The third ventricle is in _________ the Thalamus

Medial Lemniscus Pathway

Receptor: joint, cutaneous, muscle

Sensation: joint position, touch, pressure (body)

Cross over: medulla

Spinal Cord: posterior column (Fasciculus Gracilis and Fasciculus Cuneatus)

Brain Stem: Neuleus Gracilis and Neuleus Cuneatus → Medial Lemniscus

Thalamus: Ventral Posterolateral Nucleus (VPL)

Cerebral Cortex: Primary Somatosensory

Spinothalamic Tract

Receptor: skin receptor

Sensation: pain, temperature, itch, light touch (body)

Cross over: anterior white commissure at S.C.

Spinal Cord: anterolateral spinothalamic tract

Brain Stem: anterolateral spinothalamic tract

Thalamus: Ventral Posterolateral Nucleus (VPL)

Cerebral Cortex: primary somatosensory

Trigeminothalamic Pathway

Receptor: facial receptor

Sensation: facial sensation

Cross over: medulla

Spinal Cord: N/A

Brain Stem: CN V → Trigeminal Nucleus → Trigeminothalamic Tract

Thalamus: Ventral Posteromedial Nucleus (VPM)

Cerebral Cortex: primary somatosensory

Trigeminothalamic Tract

The ___________ does not go through the S.C.

Medial Lemniscus Pathway

Senses joint position, touch, pressure (body)

Spinothalamic Tract

senses pain, temperature, itch, light touch (body)

Trigeminothalamic Pathway

facial sensation

Medial Lemniscus and Trigeminothalamic

Crosses over at the medulla

Spinothalamic Tract

Crosses over at the anterior white commissure at the S.C.

Ventral Posterolateral Nucleus (VPL)

medial lemniscus and spinothalamic terminate here at the thalamus

Ventral Posteromedial Nucleus (VPM)

Trigeminothalamic terminates here at the thalamus

posterior

The bumps are _________

anterior

The top of the Y is __________

Internal medullary lamina

What is the black arrow pointing to the Y-shape?

white (axons)

The internal medullary lamina is made up of _______ matter (______)

Interthalamic adhesion

What is the black arrow pointing to the middle of the thalamus?

no

Is the Interthalamic adhesion needed to function normally?

Medial Nucleus

What is the dark red arrow pointing to near the middle?

Anterior Nucleus

What is the light blue arrow pointing to near the top right?

Lateral Dorsal (LD) Nucleus

What is the light green arrow pointing to?

Ventral Anterior Nucleus

What is the purple arrow pointing to near the top?

Ventral Lateral Nucleus

What is the orange arrow pointing to?

Ventral Posterior Nucleus

What is the yellow arrow pointing to?

Ventral Posterolateral and Ventral Posteromedial

The Ventral Posterior Nucleus is split up into what two parts?

Lateral Geniculate Nucleus

What is the magenta arrow pointing to near the bottom?

Medial Geniculate Nucleus

What is the dark blue arrow pointing to near the bottom?

Pulvinar Nucleus

What is the dark green arrow pointing to near the bottom?

Lateral Posterior (LP) Nucleus

What is the light pink arrow pointing to?

Association Nuclei

• Medial, Pulvinar, Lateral Posterior

• from cortex

• receives info from cerebral cortex and sends info to other parts of cerebral cortex

pulvinar

The lateral posterior (LP) nucleus sends info to the __________ nucleus (they have the same cortical lobe and function)

Specific/Relay Nuclei

• anterior, lateral dorsal, ventral anterior, ventral lateral, ventral posterior, lateral geniculate, medial geniculate

• from periphery/subcortical

• relay receives info from the peripheral and relays it to the cerebral cortex

anterior

The lateral dorsal (LD) nucleus sends info to the __________ nucleus (they have the same cortical lobe and function)

Medial

Cortical Lobe: frontal

Function: cognitive/executive

Pulvinar and Lateral Posterior

Cortical Lobe: parietal

Function: sensory association

Anterior and Lateral Dorsal

Cortical Lobe: limbic (cingulate)

Function: memory/motivation

Ventral Anterior and Ventral Lateral

Cortical Lobe: frontal (motor cortex)

Function: motor control/coordination

Ventral Posterior

Cortical Lobe: parietal

Function: sensory

Lateral Geniculate

Cortical Lobe: occipital

Function: visual

Medial Geniculate

Cortical Lobe: temporal

Function: auditory

Sensory

__________ Disorders of the Thalamus

• problems distinguishing stimuli

  • type

  • location

  • intensity

• Hemianopsia (hemianopia)

• thalamic pain syndrome

• neuropsychological problems

Hemianopsia

vision loss of one side (damage to lateral geniculate)

Thalamic Pain Syndrome

every sensation is painful

Motor

_________ Disorders of the Thalamus

• sensory ataxia

• dyskinesia

• chorea

  • tremors

  • dystonia

Sensory Ataxia

no motor coordination

Dyskinesia

involuntary motion

includes:

• dystonia

• chorea

• tremors

Chorea

jerky movements

tremors, dystonia

Dystonia

change in muscle tone

Thalamic Syndrome

A combination of sensory and motor disorders. Includes:

• thalamic pain syndrome (sensory)

• hemianesthesia (sensory)

• hemiparesis (motor)

Hemianesthesia

loss of sensation on one body side

Hemiparesis

weakness on one body side

Thalamus related motor disorders

includes:

• dystonia

• hemiparesis

• tremors

• sensory ataxia

• chorea

Thalamus related sensory disorders

includes:

• hemianopsia

• hemianesthesia

• thalamic pain syndrome

• problem distinguishing stimuli