Class Notes (836,135)
Canada (509,645)
55-101 (38)
Habetler (38)
Lecture

Motor System II

1 Page
55 Views
Unlock Document

Department
Biological Sciences
Course
55-101
Professor
Habetler
Semester
Fall

Description
Outline of Lecture 37 (03-05 B; Shadmehr) Motor System II – Descending Tracts 0. Motor control is a high level action, e.g. it may involve complex joint motions but smooth trajectories I. CORTICOSPINAL TRACT - Origin at premotor cortex, motor cortex (M1), somatosensory cortex (S1) - Axons run through pyramids (medulla) and 90% cross in lower medulla to form lateral corticospinal tract and 10% remain ipsolateral mostly going to ventral corticospinal tract - Split-brain patients (surgical separation of corpus callosum) - Distribution of CST fibers provides good control of contralateral arm/hand, but poor control of ipsolateral and little control of ipso. hand - Language center is on left hemisphere, can only vocally identify items perceived by right side of body (thus left arm is an “alien arm”) - Conduction speed in CST increases early in life due to myelination but remains relatively constant afterwards despite growth/lengthening of pathway II. TECTOSPINAL TRACT - Origin at tectum (midbrain), crosses in caudal midbrain, terminates in cervical spine - Function unclear (don’t worry about this tract) III. RUBROSPINAL TRACT - Origin at red nucleus (midbrain), and receives input from cortex (M1) and cerebellum - Crosses immediately after origin, descends laterally to excite arm and
More Less

Related notes for 55-101

Log In


OR

Join OneClass

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

Sign up

Join to view


OR

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.


Submit