Medula Espinal: Vias Aferentes ou ascendentes (sensibilidade) - Sistema Nervoso - VideoAula 092

Summary

In this video lesson, Rogério explains the concept of afferent pathways in the spinal cord, which are responsible for transmitting sensory information from the peripheral nervous system to the central nervous system. He introduces several tracts, including spinocerebellar, spinothalamic, and fasciculi gracilis and cuneatus, and discusses the types of stimuli they carry, such as tactile, pain, temperature, proprioception, and vibration. The video also touches on the crossing of signals in the spinal cord and provides useful tips for understanding sensory functions and further study of related subjects.

Takeaways

• 😀 Afferent pathways, also known as ascending or sensory pathways, carry stimuli from the peripheral nervous system to the central nervous system.
• 😀 The main goal of the video is to explain the afferent pathways and the types of stimuli they carry to the brain or cerebellum.
• 😀 The prefix 'spino' in the names of pathways (e.g., spinocebellar, spinothalamic) indicates an afferent pathway.
• 😀 The afferent pathways include the spinocerebellar tracts, spinothalamic tracts, and fasciculi gracilis and cuneiforme.
• 😀 Stimuli like touch and pressure travel through the spinothalamic anterior tract to the brain, while pain and temperature stimuli use the spinothalamic lateral tract.
• 😀 Proprioception, or unconscious awareness of body position, is carried through the spinocerebellar tracts to the cerebellum.
• 😀 Sensory stimuli mostly cross over (decussate) to the opposite side of the spinal cord before reaching the brain.
• 😀 Fasciculi gracilis and cuneiforme convey sensations like stereognosis (recognition of objects by touch), proprioception, and vibration.
• 😀 The fasciculi gracilis and cuneiforme are responsible for fine touch recognition, especially in the hands, with sensitivity to tiny vibrations.
• 😀 Afferent pathways play a crucial role in conveying tactile sensations (e.g., pressure, touch), proprioception, pain, and temperature to the central nervous system.

Q & A

What are afferent pathways in the spinal cord?

Afferent pathways are responsible for transmitting sensory information from the peripheral nervous system to the central nervous system, specifically to the brain or cerebellum. These pathways are also known as ascending or sensory pathways.

What does the term 'afferent' mean in the context of neural pathways?

In neural pathways, 'afferent' refers to the direction of information flow, meaning it carries sensory stimuli from the body to the central nervous system, moving in an ascending direction.

How do afferent pathways differ from efferent pathways?

Afferent pathways carry sensory information to the brain or cerebellum, while efferent pathways carry motor commands from the brain to the body, resulting in movement or action.

What are tracts and fasciculi in the context of spinal pathways?

Tracts and fasciculi are bundles of nerve fibers that transmit sensory or motor information. In afferent pathways, these structures, such as the spinocerebellar and spinothalamic tracts, carry specific types of sensory stimuli.

What is the role of the spinocerebellar tracts?

The spinocerebellar tracts carry proprioceptive information from the body to the cerebellum, helping to maintain balance and coordination by informing the cerebellum of the body's position and movement.

What kind of sensory information is carried by the spinothalamic tracts?

The spinothalamic tracts carry information about pain, temperature, touch, and pressure. The anterior spinothalamic tract conveys touch and pressure, while the lateral spinothalamic tract conveys pain and temperature sensations.

What is the significance of the decussation (crossing) of pathways in the spinal cord?

The decussation refers to the crossing of sensory pathways to the opposite side of the spinal cord. This ensures that sensory information from the right side of the body is processed by the left hemisphere of the brain and vice versa.

What is proprioception and how is it conveyed by the spinal pathways?

Proprioception is the sense of body position and movement. It is conveyed unconsciously to the cerebellum through the spinocerebellar tracts, which carry information from muscle spindles and joint receptors to help maintain posture and balance.

What is stereognosis, and which spinal tract is involved in this sense?

Stereognosis is the ability to recognize objects through touch without looking at them. It involves the fasciculus gracilis and cuneatus pathways, which convey fine touch and proprioceptive information to the brain.

What are the four types of sensory information carried by the spinal pathways mentioned in the lesson?

The four types of sensory information carried by the spinal pathways are: 1) Stereognosis (object recognition by touch), 2) Proprioception (body position awareness), 3) Epicritic touch (fine touch recognition), and 4) Vibration sense (deep touch sensation).