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Biology-Related Homework Help Anatomy and Physiology Topic started by: jkasick on Nov 5, 2012



Title: Contraction of Motor Units
Post by: jkasick on Nov 5, 2012
The Muscular System: Contraction of Motor Units
1.    Define a motor neuron:_____A single nerve cell that branches from the brain or the spinal cord to a muscle or a gland.
2.   Define a motor unit: ___A motor neuron and all of the muscle fibers it stimulates.
3.    The synapse between a motor neuron and the muscle it innervates is called a ____neuromuscular junction_______.
4.    The stimulation of additional motor units will increase the strength of the contraction.  This process is called ____recruitment______________ _____.
5.   The muscles of the eye need to make precise small motor movements.  Therefore, you would find (large or small) motor units in the eye.
The muscles of the thigh exhibit gross movements for walking.  Therefore, you would find (large or small) motor units in the thigh.
6.   How is muscle tone maintained in the muscle? ___Impulses of the spinal cord and in some muscles controlled by cranial nerves the impulses come from the brain.
If the nerve to a muscle is cut, what will happen to the muscle?_The muscle would suffer paralysis and would atrophy.
7.   What was the size of the motor units required in the arms and legs of the offensive player so that he could make the basket? (Quiz section)
arms __medium_______      
legs ___large_______


Title: Re: Contraction of Motor Units
Post by: bio_man on Nov 5, 2012
7.   What was the size of the motor units required in the arms and legs of the offensive player so that he could make the basket? (Quiz section)
arms __medium_______      
legs ___large_______

Arms, medium; legs, large


Title: Re: Contraction of Motor Units
Post by: bio_man on Nov 5, 2012
3.    The synapse between a motor neuron and the muscle it innervates is called a ____neuromuscular junction_______.

neuromuscular junction

Hope these help. Let me know if you need the others.