Ascending tracts — slide header + short list of principal tracts:
Descending (Motor): Generally use a two-neuron system. Upper motor neurons (UMN) originate in the brain and descend to the spinal cord, where they synapse with lower motor neurons (LMN) that innervate the target muscles.
- Clinical Pearl: This explains why a stroke on the left side of the brain affects the right side of the body.
Grab the PPT here: [Insert Link]
- Differentiate between ascending (sensory) and descending (motor) tracts.
- Name the major tracts and their functions.
- Trace the pathway of key tracts (e.g., spinothalamic, corticospinal).
- Understand clinical signs of tract lesions.
Ascending and Descending Tracts of Spinal Cord: A Comprehensive Overview ascending and descending tracts of spinal cord ppt
- Sensory deficits: Damage to ascending tracts can lead to loss of sensation, numbness, or tingling in the affected areas.
- Motor weakness or paralysis: Damage to descending tracts can result in muscle weakness, paralysis, or loss of coordination.
- Spinal cord injuries: Traumatic injuries to the spinal cord can damage both ascending and descending tracts, leading to significant functional impairments.
Slide 16: Q&A / Discussion
- “Why is pain/temp preserved in dorsal column lesions?”
- “Which tract is responsible for the Babinski sign?”
- “How would you differentiate a cord hemisection from a peripheral nerve injury?”
Slide 8: Descending Tracts – Overview (Motor)
- Function: Control voluntary movement, posture, muscle tone, reflexes.
- Upper Motor Neuron (UMN): Brain → spinal cord.
- Lower Motor Neuron (LMN): Ventral horn → muscle.
- Two main groups: Corticospinal (pyramidal) & Extrapyramidal tracts.