Descending Tracts Need-to-Know Flashcards
Is the Anterior Corticospinal Tract (Pyramidal or Extra Pyramidal)?
Pyramidal
Is the Lateral Corticospinal Tract (Pyramidal or Extra Pyramidal)?
Pyramidal
Is the Tectospinal Tract (Pyramidal or Extra Pyramidal)?
Extra Pyramidal
Is the Rubrospinal Tract (Pyramidal or Extra Pyramidal)?
Extra Pyramidal
Is the Vestibulospinal Tract (Pyramidal or Extra Pyramidal)?
Extra Pyramidal
Is the Reticulospinal Tract (Pyramidal or Extra Pyramidal)?
Extra Pyramidal
What Descending Tracts are Pyramidal?
The Anterior & Lateral Corticospinal Tract
What Descending Tracts are Extra Pyramidal?
- Tectospinal
- Rubrospinal
- Vestibulospinal
- Reticulospinal
What is the function of the Anterior Corticospinal Tract?
Initiate Axial Musculature
What is the function of the Lateral Corticospinal Tract?
Initiate precise, skilled, voluntary movements (mainly distal extremities)
What is the function(s) of the Tectospinal Tract?
- Extrapyramidal postural reflex in the neck
- reflex enhancement w/ sight and auditory inputs
What is the function of the Rubrospinal Tract?
Muscle tone control primarily in contralateral hand and foot musculature.
What is the function of the Vestibulospinal Tract?
Maintains proper orientation in falling and enhances spinal reflex capability.
What is the function of the Reticulospinal Tract?
Heart, blood pressure, and respiratory rates and rhythms
Where does the Anterior Corticospinal Tract cross over?
Prior to termination in R.L. 7
Where does the Lateral Corticospinal Tract cross over?
pyramids of the M.O.
Where does the Tectospinal Tract cross over?
as they descend
Where does Rubrospinal Tract cross over?
Midbrain as they descend
Where does the Vestibulospinal Tract cross over?
Does not cross over
Where does the Reticulospinal Tract cross over?
mostly UNCROSSED
What cord levels is the Anterior Corticospinal Tract found?
Terminate by T6
What cord levels is the Lateral Corticospinal Tract found?
Entire length of the cord
What cord levels is the Tectospinal Tract found?
Terminates @ C4
What cord levels is the Rubrospinal Tract found?
All levels
What is the Main source of influence of the Anterior Corticospinal Tract?
Cerebrum
What is the main source of influence of the Lateral Corticospinal Tract?
Cerebrum
What is the Main source of influence of the Tectospinal Tract?
Cerebellum
What is the Main source of influence of the Rubrospinal Tract?
Cerebellum
What is the Main source of influence of the Vestibulospinal Tract?
Cerebellum
Where does the Anterior Corticospinal Tract originate?
Motor Cortex (aka Post-Central Gyrus)
Where does the Lateral Corticospinal Tract originate?
Motor Cortex (aka Post-Central Gyrus)
Where does the Tectospinal Tract originate?
Superior Colliculus of the Tectum in the Midbrain
Where does the Rubrospinal Tract originate?
Magnocellular region of Red Nucleus in Tegmentum of Midbrain
Where does the Vestibulospinal Tract originate?
Deiters’ Nucleus (lateral part of Vestibular Nucleus of M.O.)
Where does the Reticulospinal Tract originate?
Reticular Formation
What Rexed Laminae are associated with the Anterior Corticospinal Tract?
7
The Anterior Corticospinal Tract has ___% of Total Corticospinal Fibers.
5-15%
The Lateral Corticospinal Tract has ___% of Total Corticospinal Fibers.
85-95%
The Lateral Corticospinal Tract synapses in ___ then take a 2nd internuncial fiber to ____.
Rexed Laminae 7
Rexed Laminae 9
Fibers exit the Lateral Corticospinal Tract thru the…
Lower Motor Neurons
What cells are located in the Lateral Corticospinal Tract?
Giant Pyramidal (Betz) Cells
What descending tract(s) may assume Corticospinal function if the Corticospinal Tract is damaged?
Rubrospinal and Reticulospinal
What is the only descending tract to originate in the Medulla Oblongata?
Vestibulospinal
What is the function of the Fasciculus Proprius Tract?
Spinal Reflexes
What is the first tract to be myelinated in the fetus?
Fasciculus Proprius
What is the tract located between Rexed Lamina 1 and the posterior lateral sulcus of the cord?
Dorsolateral Tract (Lissauer)