Ascending and Descending Spinal Cord Tracts Made Easy

Summary

This video script explores the anatomy and function of the spinal cord's tracts, dividing them into ascending and descending pathways. The ascending tracts carry sensory information, with distinct pathways for touch, pressure, pain, temperature, and proprioception. The descending tracts, responsible for muscle movement, include the pyramidal and extrapyramidal tracts, which control voluntary and involuntary muscle functions. The script highlights specific pathways like the dorsal column, spinothalamic, and cerebellar tracts, providing an in-depth explanation of how these systems operate to transmit sensory and motor information in the body.

Takeaways

• 😀 The spinal cord has ascending (sensory) and descending (motor) tracts.
• 😀 White matter in the spinal cord gets its color from the myelin around the axons.
• 😀 Gray matter is centrally located and consists of ventral and dorsal horns.
• 😀 Ascending pathways are responsible for transmitting sensory information from the body.
• 😀 The dorsal column tracts (fasciculus gracilis and cuneatus) carry signals for fine touch, vibration, and proprioception.
• 😀 The fasciculus gracilis carries sensory signals from the lower limbs, while the fasciculus cuneatus carries signals from the upper limbs.
• 😀 Anterolateral pathways (anterior and lateral spinothalamic tracts) carry signals for crude touch, pressure, pain, and temperature.
• 😀 Anterior and lateral spinothalamic tracts decussate in the spinal cord, leading to contralateral loss of sensation in case of injury.
• 😀 Spinal cerebellar tracts transmit unconscious proprioceptive information about the lower and upper limbs to the cerebellum.
• 😀 Descending pyramidal tracts (corticospinal tracts) control voluntary muscle movement, with the lateral tract decussating at the medulla.
• 😀 Extrapyramidal tracts (rubrospinal, reticulospinal, vestibulospinal, and tectospinal tracts) regulate motor control, muscle tone, balance, and posture.

Q & A

What are the two main divisions of tracts in the spinal cord?

The two main divisions of tracts in the spinal cord are ascending tracts and descending tracts.

Why is the white matter of the spinal cord called 'white'?

The white matter of the spinal cord is called 'white' because of the myelin around the axons, which gives it a whitish appearance.

What is the function of the ascending tracts in the spinal cord?

The ascending tracts in the spinal cord are responsible for transporting sensory information from the body to the brain.

What is the difference between the fasciculus gracilis and fasciculus cunatus?

The fasciculus gracilis transmits sensory information from the lower limbs (below T6), while the fasciculus cunatus carries sensory information from the upper limbs (T6 and above).

What sensory information do the fasciculus gracilis and fasciculus cunatus tracts carry?

The fasciculus gracilis and fasciculus cunatus tracts carry fine touch, vibration, and proprioception sensations.

How does a spinal cord injury affect sensation related to the dorsal column tracts?

A spinal cord injury results in the loss of ipsilateral fine touch, vibration, and proprioceptive sensation because these tracts run ipsilaterally through the spinal cord.

What is the role of the anterior and lateral spinothalamic tracts?

The anterior spinothalamic tract is responsible for crude touch and pressure, while the lateral spinothalamic tract carries pain and temperature sensations.

What happens when the spinal cord is damaged in relation to the anterolateral pathways?

Damage to the spinal cord causes a contralateral loss of crude touch, pressure, pain, and temperature sensation due to the crossing of these pathways at the spinal cord level.

What is the role of the posterior and anterior spinal cerebellar tracts?

The posterior and anterior spinal cerebellar tracts transmit unconscious proprioceptive information from the lower limbs to the cerebellum.

How do the pyramidal tracts contribute to muscle movement?

The pyramidal tracts, which include the anterior and lateral corticospinal tracts, carry voluntary motor signals from the brain to the spinal cord, facilitating limb movement.