White Matter Flashcards
- The Dorsal Root Entry Zone is the entry zone for _________ ______ ______ neurons of the ___
- It’s axons become segregated according to fiber ____ and _____
- Primary sensory afferent neurons of the DRG
- Size and function
Large myelinated axons ( de mecanoreceptores de la piel y propioreceptores del musculo y tendones) forman un ____ _____ entrando al _____ column y terminando en el _____ laminae del _____ horn
- Medial bundle
- dorsal column
- deep laminae
- dorsal horn
Small Myelinated or unmyelinated axons (dolor, temperatura, sensaciones vicerales) forman un _____ budle, el tracto de _____, que termina directamente en en las lamina __ y __.
- Lateral bundle
- Tracto de Lissauer
- Laminas 1 y 2
Identifica los 4 tractos asendientes de la materia blanca.
- Fasciculus Gracillis
- Fasciculus Cutaneus
- Spinocerebral tract Dorsal (posterior) y Ventral (anterior)
- Spinothalamic tract Lateral y Ventral (anterior)
Identifica los 5 (uno no sale en la foto) trayectos decendientes del WM:
- Remember (CROV TC)
- Corticospinal Tracts Lateral & Ventral (anterior)
- Rubrospinal
- Reticulospinal
- Vestibulospinal Lateral & Medial
- Tectospinal
Qué dos tractos acendientes quedan en las las columnas dorsales?
- Fasciculus Gracilis
- Fasciculus cutaneus
Que tractos quedan en las columnas laterales
- 3 acendiendo
- 2 decendiendo
- Acendiendo:
- Dorsal Spinocerebellar tract
- Ventral Spinocerebellar tract
- Lateral Spinothalamic tract
- Decendiendo:
- Lateral corticoespinal
- Rubroespinal
Qué tractos quedan en la columna ventral:
- 1 acendiente
- 4 decendientes
- Acendientes: Ventral (anterior) Spinothalamic
- Decendientes:
- Ventral Corticoespinal
- Reticuloespinal
- Vestibuloespinal
- Tectospinal
A spinal reflex involves exitation of a ______ neuron in response to ______ stimulation.
- Motor neurons
- In response to afferent stimulation
Spinal reflexes are normally modulated by _______ mechanisms and become exaggerated when the influences are _____ due to damage of these descending pathways.
- Supraspinal mechanisms
- lost
- In segemental spinal reflexes an ____ motor neuron, its axon and all the muscle fibers it innervates constitute a _____ unit.
- Motor neurons innervating one muscle are usually clustered into an elongated motor nucleus of lamina ___ that may extend ___ to __ segments
- alpha motor neuro
- motor unit
- 9(IX)
- 1 to 4 segments
Motor neurons project axons to muscle fibers where they form a specialized synapse calle the: ________
Motor end plate.
Muscle spindles are specialized structures found within muscles designed to provide signals to the ___ corcerning changes in ______
- CNS
- Muscle lenght and the rate of change in muscle length.
*
What are the three main components of muscle spindles:
- Intrafusal muscle fibers- solo los extremos son contractiles
- Ia and II sensory endings- se origiinan en la región central de las “intrafusal fibers”.
- Gamma- motor endings- inervan los extremos contractiles de las fibras.
Como los “muscle spindles” están organizados en paralelo con “________ muscle fibers”, durante el movimiento voluntario es necesario activar las fibras motoras _____ para mantener tensión en las “intrafusal fibers”.
- Extrafusal muscle fibers
- Gamma
