Motor

Question 1

what does a motor unit consist of ?

Answer 1

one alpha motor neuron, innervated muscle fibre= a motor unit

Question 2

what is the ventral horn somatotopic arrangement for body parts?

Answer 2

in the y axis= the more dorsal are the flexors, the more ventral are the extensors.
in the x-axis= from lateral to medial we have hand, forearm, arm, shoulder, trunk.

Question 3

what type of neurons are UM neurons?

Answer 3

pyramidal glutamatergic .

Question 4

what type of neurons are LM neurons?

Answer 4

cholinergic- skeletal muscle is alpha

muscle spindle is gamma.

Question 5

alpha motor neuron’s cell bodies are called…..

Answer 5

perikarya

Question 6

What is the tract innervating gamma motor neurons?

Answer 6

the tracts in the brainstem which mainly regulate muscle tensions.

Question 7

what type of input inhibits lower motor neurons?

Answer 7

supraspinal input through UMN. if lost-spastic paralysis

Question 8

what are the muscles innervated by oculomotor nerve?

Answer 8

medial, inferior and superior rectus, inferior oblique, levator palpebrae.

Question 9

what nerve innervates superior oblique and lateral rectus?

Answer 9

superior oblique-trochlear

lateral rectus- abducens