Motor Tracts Flashcards
Which of the following are lower motor neurons which directly innervate skeletal muscle, and cell body is found in spinal cord or brain stem?
A. Corticospinal Tracts
B. Corticobulbar tracts
C. Medial Lemniscal Tracts
D. Cranial Nerves
Cranial Nerves
The Corticospinal tract includes voluntary motor movement and can be divided into medial and lateral tracts.
What muscles are targeted by the Medial Corticospinal Tract?
What muscles are targeted by the Lateral Corticospinal Tract?
Medial Corticospinal: Postural and Axial muscles
LAteral Corticospinal: Limb muscles
Describe the General Pathway of the Direct Corticospinal Tract and be sure to indicate where it decussates
Cortex
Posterior Limb of Internal Capsule
Cerebral Peduncles (Midbrain)
Anterior Pons
Medullary Pyramids (decussation station)
Lateral column of the spinal cord
What cortex in the brain gives rise to the Corticospinal tract?
Primary motor cortex found in the Precentral Gyrus
T/F: More cortical area is needed if number of motor units in a muscle is high like in vocal cords, tongue, lips, fingers, and thymb
True
What is the vascular supply to the internal capsule?
Lenticularstriate As.
The tracts to the legs travel _______, while the tracts to the arms travel _______
The tracts to the legs travel laterally, while the tracts to the arms travel medial
What is the blood supply to the Anterior Pons?
Paramedian Basilar A.
What is the blood supply to the medullary pyramids?
Sulcal branches of the Anterior Spinal A.
Within the spinal cord, neurons targeting the leg are supplied by what artery?
Neurons targeting the arms are supplied by what artery?
Posterior Spinal A.
Sulcal Branches of Anterior Spinal A.
THe UMN of the Lateral Corticospinal Tract synapse with the lower motor neurons in the _________ of the spinal cord
Ventral Horn
The Medial Corticospinal Tract controls postural and axial muscles (neck, shoulders, trunk), the pathway is similar to the lateral corticospinal tract, but differs in what way?
Medial Corticospinal Tract fibers DON’T cross in the medulla and stay ipsilateral
The Corticobulbar Tract arises from the ventral portion of the 4th cortical area. It descends into the brain stem and influences muscles innervated by cranial nerves with motor nuclei. What are those cranial nerves?
5
7
9
10
11
12
What cranial nerve motor nuclei is found in the pons?
5 and 7
What cranial nerve motor nuclei are found in the rostral medulla?
9, 10, 12
What cranial nuclei are found in the spinal cord?
11
What is the general pathway of the corticobulbar (corticonuclear) tract?
Genu of Internal Capsule
Cerebral Peduncles
Anterior Pons
Medullary Pyramids (deccussation station)
Along the way it will stop at specific motor nucleus
Which of the following is true of CN V in terms of input from corticobulbar tract?
A. recieves bilateral input from the corticobulbar tract
B. receives contrlateral input from the corticobulbar tract
C. receives ipsilateral input from the corticobulbar tract
recieves bilateral input from corticobulbar tract
Which of the following is true of CN VII targeting areas of the forehead in terms of input from corticobulbar tract?
A. recieves bilateral input from the corticobulbar tract
B. receives contrlateral input from the corticobulbar tract
C. receives ipsilateral input from the corticobulbar tract
recieves bilateral input from the corticobulbar tract
Which of the following is true of CN VII targeting the lower face in terms of input from corticobulbar tract?
A. recieves bilateral input from the corticobulbar tract
B. receives contrlateral input from the corticobulbar tract
C. receives ipsilateral input from the corticobulbar tract
receives contrlateral input from the corticobulbar tract
Which of the following is true of CN IX and X from the nucleus ambiguus, in terms of input from corticobulbar tract?
A. recieves bilateral input from the corticobulbar tract
B. receives contrlateral input from the corticobulbar tract
C. receives ipsilateral input from the corticobulbar tract
receives contrlateral input from the corticobulbar tract
Which of the following is true of CN XI in terms of input from corticobulbar tract?
A. recieves bilateral input from the corticobulbar tract
B. receives contrlateral input from the corticobulbar tract
C. receives ipsilateral input from the corticobulbar tract
receives ipsilateral input from the corticobulbar tract
Within the spinal cord, where will you find the LMNs that correlate to axial muscles, limb muscles, extensors, or flexors?
Flexors: Posterior/Dorsal
Axial muscles: Medial
Extensors: Anterior/Ventral
Limb muscles: Lateral
- Remeber: FLEA*
- F*
- L A*
- E*
What is true of indirect pathways?
A. They decussate in the cerebellum
B. They are always active
C. They are all supplied by Posterior Spinal A.
D. Tonically activate antigravity and axial LMN
E. A and D
F. B and D
B and D
They are always active
Tonically activate antigravity and axial LMN