Motor neurons and muscles

Motor neurons and long-term
Muscle Effects

My Understanding:My Understanding:

Peggy Mason's explanation of Motorneurons
and its effect on Muscle fibers and ultimately
long-term muscle gain; the fast fatiguable motor
units using Glycogen, was an eye-opener for
me!

Parts of the Nervous System active:Parts of the Nervous System active:

My discussion will be on a motor unit containing
one motor neuron - a cell located in our central
nervous system that transmits information by
electrical and chemical signaling - and all
muscle fibers connected to it.

The power of a muscle’s contraction
depends on the following five things:
1. Number of Motor Neurons Used
2. Strength of the Impulse Sent by Each Motor
Neuron
3. Size of the Muscle
4. Intra-muscular Coordination
5. Inter-muscular Coordination

Source: http://www.humankinetics.com/excerpts/excerpts/learn-how-muscles-build-up-strength -
31 March 2017; 10 am IST.
Functions of the Nervous System that areFunctions of the Nervous System that are
apparent:apparent:

1. Number of Motor Neurons Used

A strong person is someone who has the ability to use the maximum amount
of his muscle fibers at a given moment. The use of these muscle fibers is
carried out by the central nervous system.

Everything starts at the cerebral level: The command given to contract
muscles goes through the nerves in the spinal cord. Motor neurons then
carry the command to the muscle fibers. Each motor neuron controls the
contraction of a specific group of fibers. The more motor neurons that are
activated, the greater the quantity of muscle fibers that will contract. This is
why training should be done with heavy weights. The heavier the weight we
lift, the more motor nerves we will be able to use simultaneously.

2. Strength of the Impulse Sent by
Each Motor Neuron

Motor neurons can send electrical impulses to muscles with varying
frequency. If the frequency is low, the muscle contracts sluggishly. However,
motor neurons can send a flurry of intense impulses that act powerfully on
muscle fibers.

The intensity of our training develops our capacity to do the most repetitions
possible with a heavy weight. Doing plyometrics also plays an important part
in increasing the power of nerve impulses.

3. Size of the Muscle

There is a strict correlation between the size of muscle fibers and the
strength they are capable of developing. The stronger a section of muscle
fibers that is linked to a motor neuron, the more force will be generated by a
nerve impulse.

We can develop muscle mass by performing weight training exercises with a
weight that is around 80 percent of our maximum strength.

4. Intra-muscular Coordination

In a sedentary person, when motor neurons discharge their electrical
impulses, they do so in a disorderly fashion. The muscle fibers contract in a
random, and therefore inefficient, way.

Through training, these discharges become synchronized. The fibers begin
contracting in a coordinated manner. Muscles become more efficient.

We can achieve this by doing weight training exercises with a weight that is
close to our repetition maximum.

5. Inter-muscular Coordination

It is rare that we have to contract only one muscle at a time. Generally, a
whole group of muscles is activated to produce a movement. When
resistance becomes greater, the muscles of inexperienced athletes have a
hard time working together in an efficient manner. We can see this when
such athletes do pull-ups. They lean to one side more than the other. They
cannot pull themselves up in a linear fashion and without jerky movements.
The body shifts from front to back.

Through training, the quality of movement improves, simply because the
arms will have learned to work together with the back muscles, and the
muscles on the right side will be in synch with the muscles on the left side.

This gain in efficiency translates to an increase in strength. It is the same in
all areas of fitness when we have to learn a new move. It is the volume of
work, and therefore the repetition of a movement or an exercise, that
improves inter-muscular coordination.

Through regular weight training, an athlete’s muscles become accustomed
to working together. This advanced work means that an athlete can learn
new movements more quickly if he has already been weight training for
months.

Summary of power of a muscle’s
contraction

In summary, among the elements described,
the size of a muscle is just one of five factors of
strength. To increase power and strength, a
weight training program must also improve the
four factors that are part of the central nervous
system.

Fast Fatigables and Endurance

When we begin to lift weights, the next day, we are able to recruit more fast
fatigable fibers in the muscle that we exercised. And that, that ease of
recruitment of fast fatigable fibers due to one strength exercise bout lasts for
weeks. So if we want to get more fast fatigables online, lift weights.

Now one other thing that we should look at is what happens when we lose
various types of, of motor units. If we lose these slow motor units we're going
to have a problem with endurance. And if we lose the fast fatigables or if we
don't actually ever engage them because we're leading a very, very
sedentary life we're going to lose strength. So, these different types of motor
neurons and motor unit, motor unit types differentially effect endurance and
strength.

It, it holds the promise of being able to give people who have lost strength
some more strength back if we could, for instance, switch a slow fiber into a
fast fiber. It's not easily done, if at all, but it's definitely something that holds
promise for the future.

Central Nervous System and real-life MuscleCentral Nervous System and real-life Muscle
Building / Weight Lifting ScenarioBuilding / Weight Lifting Scenario

Orderly Recruitment
Exercising impacts how we recruit our motor
units. And it has a big effect.
Strength training, lifting weights immediately
starts to increase the likelihood that fast
fatiguable motor units will be recruited.


Orderly Recruitment
After a single bout of lifting weights, we're going
to get much closer to 100%.
In addition, the ability of these fast fatiguables
and the firing pattern of them will change. So
that the likelihood that more force happens, is
increased.
And that is essentially through a firing pattern
whereas instead of doing this, there's an action
potential like that. These are these doublets.


Orderly Recruitment
And two action potentials right next to each other.
The doublets produce more force for than
single action potentials.
Now all of these things are short term. They
happen pretty immediately. They last for about
three weeks.


Orderly Recruitment
What happens in three weeks?
Muscle mass growth.
So, there is this transition from neural
mechanisms of strength to muscle mechanisms
of strength. The muscle fiber itself can grow.
And that increases the force that the muscle
fiber produces.


Orderly Recruitment
And so in about three weeks, it's the muscle fiber
that has grown, and now the recruitment stays
but, some of these other, short term
adaptations pale in comparison to the increase
in muscle size.
So the muscle mass grows. And the contractility
of the muscle also can change.

END NOTEEND NOTE
Therefore, short term, there i™s a lot of neural
effects.
And then more long term, get a lot of muscle
effects.
Central Nervous System, its Orderly Recruitment,
the Muscle Fibers...How Scientific is BodyHow Scientific is Body
Building!Building!
Truly, this was an amazing Learning that I had
from this Course from such a wonderful Teacher
in Peggy Mason.

Motor neurons and muscles

Recommended

Recommended

More Related Content

What's hot

What's hot (19)

Similar to Motor neurons and muscles

Similar to Motor neurons and muscles (20)

Recently uploaded

Recently uploaded (20)

Motor neurons and muscles