Anatomy LE 6: Pyramidal and Extrapyramidal Tracts

What percentage of the entire corticospinal tract do the pyramidal cells of Betz give rise to?

3%

Where are the pyramidal cells of Betz located?

5th layer of the cortical surface

What percentage of the precentral gyrus do the pyramidal cells of Betz give rise to?

10%

What is the functional area of the precentral gyrus (BA 4)?

Primary motor cortex Signup and view all the answers

What type of movements are the pyramidal cells of Betz responsible for?

Highly-skilled movements Signup and view all the answers

Where do the axons of the pyramidal cells of Betz send their axons directly to?

Anterior horn cells in the spinal cord Signup and view all the answers

What is the significance of the tongue, lips, face, fingers, and hands in the motor homunculus?

They are represented on a much larger scale Signup and view all the answers

What is the reason why more neurons are needed to control the movements of the tongue, lips, face, fingers, and hands?

They require more neurons to control Signup and view all the answers

What is the primary function of the corticospinal tract?

To control discrete, skilled movement, especially in distal parts of limbs Signup and view all the answers

What is the role of the basal ganglia in the execution of movement?

To support the production of well-coordinated movements Signup and view all the answers

What is the likely side of the lesion based on the symptoms?

Left Signup and view all the answers

What is the function of the premotor area in the execution of movement?

To prepare the movement Signup and view all the answers

What type of tract is affected, causing the motor deficit?

Corticospinal Tract Signup and view all the answers

What tract is responsible for transmitting command information from the motor area to the brainstem centers?

Corticobulbar tract Signup and view all the answers

What is the cause of the hyperreflexia in the right upper extremity?

Upper motor neuron lesion Signup and view all the answers

What is the origin of the desire to move in the execution of movement?

Association areas Signup and view all the answers

What is the function of the Lower Motor Neuron (LMN) in the execution of movement?

To execute the movement and raise the hand Signup and view all the answers

Why can a spinal cord lesion be ruled out as the cause of the symptoms?

Because the symptoms are on the same side as the lesion Signup and view all the answers

What is the function of the corticobulbar tract in the pyramidal system?

To transmit command information to the brainstem centers Signup and view all the answers

What is the normal or abnormal status of the MSE?

Normal Signup and view all the answers

What is the role of the cerebellum in the execution of movement?

To funnel information from the association areas to the premotor and motor areas Signup and view all the answers

Which tract is responsible for transmitting pain and thermal sensations?

Lateral Spinothalamic Tract Signup and view all the answers

What is the location of the fibers that have already crossed in the Dorsal Column-Medial Lemniscal System?

Medulla Signup and view all the answers

What type of lesion would cause a motor deficit on the same side as the lesion?

Lower motor neuron lesion Signup and view all the answers

What is Amyotrophic Lateral Sclerosis (ALS)?

A chronic progressive disease of unknown etiology Signup and view all the answers

At what age does Amyotrophic Lateral Sclerosis (ALS) typically occur?

Late middle age Signup and view all the answers

How long is the average survival time of someone with ALS?

2-6 years Signup and view all the answers

What percentage of ALS cases are inherited?

~10% Signup and view all the answers

What is affected in the spinal cord when there is a UMN lesion?

Lateral funiculus Signup and view all the answers

What is affected in the spinal cord when there is an LMN lesion?

Anterior gray column Signup and view all the answers

What is the term for the tracts that are affected in UMN lesions?

Pyramidal tracts Signup and view all the answers

What is the name of the challenge that made ALS more well-known?

Ice bucket challenge Signup and view all the answers

Where do the Corticobulbar Tract fibers pass through?

Genu of the internal capsule Signup and view all the answers

What type of cells are found in Layer 5 of the cerebral cortex?

Large pyramidal cells of Betz Signup and view all the answers