Motor Nervous System Flashcards
Where do upper motor neurons arise
The brain eg. Motor cerebral cortex
What do upper motor neurons control
Lower motor neurons
What controls lower motor neurons
Upper motor neurons
What do lower motor neurons do
Directly innervate skeletal muscle
Where are lower motor neurons located
Spinal cord or cranial nerve nuclei
Where do motor neurons leave the spinal cord
Ventral horn
The strength of a muscle contraction is controlled by:
Number if motor units activated
Frequency of action potentials
What is fasciculation
Visible twitching
Examples of lower motor lesions are
Motor neurone disease
Bells palsy
Sciatica
Myasthenia gravis
Muscular distrophy
What is a monosynaptic reflex
One synapse in CNS to same muscle
What is a polysynaptic reflex
Several synapses
What is a babinski
Sign of umn lesion
Which pathway is used by the motor system
Cortico-spinal tract
What are the four motor centres of the cerebral cortex
Basal ganglia
Cerebellum
Brainstem
Spinal cord
Hypertonia is … and is a sign of …
Increased muscle tone
Umn lesion
