Lec 1

Question 1

motor unit

Answer 1

cell body and dendrites of a motor neuron, the branches of its axon and the muscle fibres it innervates

Question 2

Muscle unit

Answer 2

all musc fibres belonging to a motor unit

Question 3

innervation ratio

Answer 3

number of fibres innervated by single motor neuron. It varies. e.g. gastroc = 1:1900, eye muscs = 1:15

Question 4

Input resistance, describe differences in small vs large neurons.

Answer 4

small neurons have high input resistance (like smaller pipes resistance vs larger pipes)

Question 5

Rheobase

Answer 5

measure of current that must be put into neuron to get it to fire. Rheobase is low in small motor neurons

Question 6

Temporal summation

Answer 6

when action potentials have not fully repolarized and build on each other.