Motor Neurons Flashcards
What happens when there is a large stimulus from the CNS
A large stimulus from the CNS recruits a large number of motor units providing a greater force of contraction
What are the three types of motor units
Type 1
Type 2a
Type 2b
Describe type one motor units (2 things)
- Small
2. Produce low force of contractions over a long period of time
Describe type 2a motor units
The force and duration of contractions is between that of type 1 and type 2a motor units
Describe type 2b motor units (2 things)
- Large
2. Produce the greatest force over a short period of time
In what order are motor units recruited
Firstly type 1a, then type 2a and then type 2b
What is a neurone
A nerve cell
What is an axon
An axon carries an electrical impulse down the neurone to the neuromuscular junction
What is the neuromuscular junction
The neuromuscular junction is where the motor neurone interacts with muscle fibres across a synapse
What is a synapse
A synapse is the space between the moron neurone and the muscle
What is the motor end plate
The motor end plate is an area of muscle that establishes synaptic contact with the neuromuscular junction
What is resting potential
Resting potential is where there is the neurone at rest and there is a lower charge inside the neurone than outside the neurone
What is action potential
Action potential is the electrical energy that is carried down the axon
What is the neurotransmitter that is transmitted from the neuromuscular junction across the synapse
Acetyl choline
What is the all or none law
The all or none law states that the action potential threshold must be reached for all the fibres in that motor neurone to contract and if it’s not reached then none of the fibres in that motor neurone will contract
