Lecture 14 Descending and Spinal Motor Pathways

What are the three main descending spinal motor pathways?

Lower motor neurons locate in Rexed _____. It is generally asembled into a _____ (proximal muscles) and _____ (distal muscles).

The axons exit the SC at ______ at the respective spinal level.

Pre-motor interneuron synapses on motor neurons in the ________.

Locate the relative areas of motor pool for muscles of different proximity.

What type of nerves are the motor nerves to 1) muscles, 2) muscle spindles?

________ motor pool is present throughout the SC while ______ motor pool only exists at plexi.

Gamma motor neurons innervates the _________ to adjust the length of ________ to maintain alignment with muscle length.

alpha-gamma co-activation is only activated by _________.

T/F: Reflex reaction activates gamma neurons.

Direct cortical control of movement has pyramid cells in lamina _______ of cerebral cortex going directly to ______ (below the neck) or _______ (facial muscles).

Indirect control has additional synapse in the ________.

corticomotor pathways to lower motorneurons are classified based on ________.

Interneuron (premotor neurons) in SC are usually found in Rexed ____, ____ or ____.

T/F: monosynaptic path is a direct pathway. However, disynpatic and polysynaptic paths are indirect pathways.

Location of the intermediate UMN in an indirect pathway.

List the spinal motor tracts and include there starting/ ending points.

Lateral motor system consists of the _____ tract and the ____ tract.

LCST is in charge of __________ control.

________ may cover LCST if there is a damage.

Medial motor system includes the _______, _______, ______ and ______.

The ventral (medial) corticospinal tract is in charge of _________.

The reticulospinal tracts are in charge of ___________ and _________.

The vestibulospinal tracts are in charge of _________ and __________.

The tectospinal tract is in charge of ____________.

Locate the tracts on a spinal cross section

Decussation of LCST locates in the _______.

Outline the pathway of LCST.

M1 correlates to BA___. It contributes to about ___% of all motor neurons.

% distribution of upper motor neurons in the cortex.

Cells in ______ are more in charge of fine motor control while cells in ______ are more concerned with postural adjustment. Supplementary motor area is in charge of ______ and ________.

The axons of corticospinal tracts mostly travel in the ______ of the internal capsule.

Area associated with hand movement is located in a more _______ location in the motor homunculus as compared to the legs.

Motor aons in the corticospinal tract going to the neck is (nearer/further) to the genu in the internal capsule.

In the midbrain, the axons of corticospinal tract lie in the __________, with areas corresponding to the legs more _______ and areas corresponding to the UE more _______.

The the axons of corticospinal tract lie in the _____ of the pons.

The cell bodies of the tectospinal tract lie in the ________ of the midbrain; while the cell bodies of the rubrospinal tract lie in the _______.

Cell bodies of the pontine reticulospinal tract lie in the ___________.

Identify the corticospinal tracts in the pons.

Identify the corticospinal tracts in the rostral medulla and the decussation fibers in the medullary-spinal junction.

The LCST terminates in Rexed ___ to synapse with spinal interneurons and in Rexed _____ to synapse with lateral motor neurons.

Outline the Rubrospinal tract and ventral corticospinal tract.

The medial motor system (ventral corticospinal tract/medial CST/anterior CST) carries more information from _____________.

T/F: VCST terminates in the caudal SC.

T/F: VCST decussates at caudal medulla.

Pontine ReST is primarily for ______ while medullary ReST is primarily for _________.

Outline the tectospinal tract