Lecture 7.2: Descending Pathways Flashcards
What are the 3 Types of Movement?
1) Reflexes
2) Posture
3) Voluntary Movement
What type of movement do LMNs & Spinal Cord Circuits facilitate?
Reflexes
What type of movement do the Brain Stem & Spinal Cord facilitate?
Posture
What type of movement do the Cortex, Brain Stem & Spinal Cord facilitate?
Voluntary Movement
What Structures is the Motor Cortex comprised of? (2)
What is the Primary Motor Cortex?
- Encodes the Direction of Movement
- Somatopically Organised
- Motor Homunculus
- Head Laterally
- Feet Medially
What is the Role of the Corticospinal Tract?
Conscious control of skeletal muscles
What 3 tracts does the Corticospinal Tract split into? (3)
- Corticobulbar
- Lateral Corticospinal
- Anterior Corticospinal
What is the Corticobulbar part of the Corticospinal Tract responsible for?
Conscious control over eye and face muscles
What is the Lateral Corticospinal part of the Corticospinal Tract responsible for?
Conscious control over limb skeletal muscles
What is the Anterior Corticospinal part of the Corticospinal Tract responsible for?
Conscious control over axial skeletal muscles
What does the Corticospinal Tract descend via?
- Pyramids of the medulla
- 75-90% decussate – mainly distal musculature
- 10-25% don’t decussate – axial
What is the Origin of the Corticospinal Tract?
Primary Motor Cortex
What does the Corticospinal tract synapse onto?
The Ventral Horn
What are the 4 Brain Stem Motor Pathways (Extrapyramidal)?
- Rubrospinal Tract
- Tectospinal Tract
- Vestibulospinal Tract
- Reticulospinal Tract