Class Notes (807,463)
Canada (492,743)
Kinesiology (2,941)


4 Pages
Unlock Document

Western University
Kinesiology 1080A/B
Matthew Heath

Kinesiology 1080 – Feb. 11, 2013 Bulb of Brainstem - It synapses onto the alpha motor neuron via monosynaptic connection (1 corticol neuron synapses to 1 alpha motor neuron Rostral & Caudal Parts of the Corticobulbar Tract - Facial nucleus is divided into rostral (innervates forehead: upper facial musculature) and caudal (innervates mouth: lower facial musculature) parts  Rostral (Upper face)  Innervates bilaterally  It sends the projections to both sides of the body: left and right  Caudal (Lower face – jaw area)  Innervates contralaterally  It sends the projections to the opposite sides of the body from the cortex (left brain is controlling the right side of the body and vice versa) - Tumor in cortex  It is an upper motor neuron injury which involves the corticobulbar area o This results in an asymmetrical innervation of the lower facial musculature  A tumor in the right cortex will lead to a contralesional paralysis affecting the left lower musculature. However, the upper face musculature is not affected by the tumor because the rostral side sends signals bilaterally (both sides) and is able to innervate the affected side - Lower Motor Neuron Injury  Bell’s Palsy (Involves the axons of the alpha motor neurons) o Causes a complete paralysis of one side of the face o When the lower motor neurons are impaired, no muscles in that area can be innervated o Both upper and lower facial musculature are affected Corticospinal tract  It has two pathways: Ventral & Lateral Ventral Corticospinal Tract  Simpler of the two corticospinal tract pathways  It originates from M1 (motor cortex), SMA & PMA; but the vast majority is from M1  It has a long axon that descends (uncrossed) down the ventral columns of the spinal cord, thus creating the ventral corticospinal tract  This is an ipsilateral connection  Majority of these connections are associated with innervating axial musculatures  these are the muscles involved in large body movements (large muscles)  This tract also tends to make connections with the propriospinal neurons  they allow for communication of neural signals between the segments of the spinal cord  This is important because the propriospinal neuron that is receiving the signal can send its projections to numerous alpha motor neurons at different levels of the spinal cord  Then these alpha motor neurons are able to go on and innervate different back or trunk muscles  The ventral corticospinal tract allows for communication and coordination between multiple muscle groups  Example: Bending at the hips  Multiple muscle groups required to support this movement  Connection via propriospinal neurons innervates multiple alpha motor neurons that might support the contraction of different types of extrafusal muscle fibres Lateral Corticospinal Tract  More sophisticated  Originated from M1, SMA, PMA & parietal cortex; majority of it originated from M1  This tract is not associated with the ventral corticospinal tract in anyway  75% of the fibres that make up the lateral corticospinal tract cross over at the level of the pyramids (pyramidal decussation) Contralateral pathway  It is very important** to know that this pathway has primary monosynaptic
More Less

Related notes for Kinesiology 1080A/B

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.