lecture9-2011

lecture9-2011 - Lecture 9- control of motor neurons! weve...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 9- control of motor neurons •we’ve covered how muscle cells contract once they have been stimulated by the motor neurons. Once a motor neuron fres , the innervated muscle will almost always contract (i.e., no summation at neuromuscular junction) - for skeletal muscle •the determining Factors on when and how strongly a muscle contracts is at level oF the neural input on the motor neuron. descending pathways inter- neuron (perForms computation) + local aFFerent input (proprioception) can be stimulatory or inhibitory +/- input From antagonistic muscle - •local aFFerent input helps to refne and control motor programs From the brain, and under certain conditions can initiate contraction independent oF the brain. Why might you want to do this? most, but not all, motor activity originates in brain + muscle fber motor neuron
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
sensorimotor cortex -Primarily mediate fne, discrete, voluntary movements. Important For coordinating actions requiring multiple muscles, making decisions on appropriate muscles to use and starting motor programs. basal nuclei -modulate the activity oF the sensorimotor cortex via the thalamus. Important For learning complex motor programs. cerebellum -does not initiate motor activity, nor strength oF contraction. Important For regulating the rate, range and direction oF movements. Damage to cerebellum result in uncoordinated movements.
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Parkinson’s Disease is caused by a loss of neurons in a part of the brain called the substantia nigra . Normally, these neurons produce the chemical messenger dopamine, which helps direct muscle movement. When the neurons become damaged, however, dopamine production stops and the body loses full movement control.
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/14/2011 for the course MCDB 111 taught by Professor Smith during the Spring '11 term at UCSB.

Page1 / 13

lecture9-2011 - Lecture 9- control of motor neurons! weve...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online