Control of Motor Movement

Dr.Mohammed Sharique Ahmed QuadriAssistant Professor

Department Basic Medical Sciences Division of Physiology Faculty of Medicine Almaarefa Colleges

بسم الله الرحمن الرحيم

Control of Motor Movement

• 3 levels of input control motor-neuron output– Input from afferent neurons– Input from primary motor cortex– Input from brain stem

The conceptual hierarchical organization of the neural system controlling body movements

The conceptualmotor controlhierarchy forvoluntary motor movements

Local control of motor neurons

Length monitoring system

Tension monitoring system

Muscle Spindle Structure

• Consist of collections of specialized muscle fibers known as intrafusal fibers– Lie within spindle-shaped

connective tissue capsules parallel to extrafusal fibers

– Each spindle has its own private efferent and afferent nerve supply

– Play key role in stretch reflex

Stretch Reflex

• Primary purpose is to resist tendency for passive stretch of extensor muscles by gravitational forces when person is standing upright

• Classic example is patellar tendon, or knee-jerk reflex

Coactivation of Alpha & Gamma Motor Neurons

Patellar Tendon Reflex( knee jerk)

Patellar Tendon Reflex knee jerk)

Neural pathways underlying Golgi tendon organ component of local control system

References

• Human physiology by Lauralee Sherwood, 7th edition

• Text book physiology by Guyton &Hall,12th edition

• Text book of physiology by Linda .s contanzo,third edition

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