The title of your essay is:-
'Identify the link between motor units, motor neural firing patterns and the sliding filament theory.'
Compare the energy systems used in team, racket and individual sports to illustrate your answer.
The deadline for you essay is Monday 12th November - Period 2
If you have any questions or aspects you are not sure about please raise them so you are in a position to provide the best answer possible.
If you have any questions or aspects you are not sure about please raise them so you are in a position to provide the best answer possible.
12 comments:
Keywords you will need to include are:-
Axon
Electrical impulse
Synoptic knobs
Wave summation
Gradation of contraction
Synoptic bulb
Calcium ions
Transverse tubules
Sarcoplasmic reticulum
ATP regeneration
ATP breakdown – energy releases Crossbridges
Glycolosis
Krebbs cycle
Electron transport chain
Please share your thoughts and ask for definitions if you are not sure.
think of ability of athlete.
novice/elite
vary of atp/pc etc depending on fitness levels!
I can describe the three energy systems in detail, but i can not understand how the amount of lactic acid produced in the lactic acid system will affect the motor neuron. Does lactic acid affect the motor neoron in that it will slow down electrical impulses, or does it effect the synoptic knobs more? How does it effect the synoptic knobs?
I am also having trouble describing in my own terms how the ATP/PC system effects the motor neuron. I understand how the ATP/PC system takes place in the muscles, and the motor neuron carries electrical impulses to the muscle fibres. Yet i can't put to words how exactly the motor neuron is effected by this system.
Have another go! Try a search engine or the index of your book and look into the effect of lactic acid on muscle tissue to gain a general understanding of the area.
Linked in with the answer is the effect of lactic acid on wave summation and gradation of muscular contraction.
Get back to me if you are still struggling...
Someone posted as anonymous and told me off for not posting their blog. Nothing came through...Sorry!
Register and I can get back to you directly.....
Can a person increase the amount of synaptic knobs/motor end plates that they have?
Follow this link. It is good background reading and may answer some of your questions:-
http://www.skoool.ie/skoool/examcentre_sc.asp?id=2879
This is another brilliant link covering the more detailed components of the question:-
http://www.shelfieldpeonline.co.uk/
html/motor_units_and_motor_neurone_
.html
At the bottom of the page you will find a great link to muscular contractions. Some of it can be ignored but the bulk has clear definitions of each area we have covered in lessons.
let me know which of the three sites is more useful......
Something on motor units:-
Source:-
http://www.kbcc.cuny.edu/
academicDepartments/bio/
11New/Webpages/MuscSysFacts.htm
Motor Units
1. The Concept - a motor unit is a motor neuron of the brain or spinal cord and all the muscle fibers within a muscle that it innervates. Different muscles have different numbers of motor units. If a muscle has only a few motor units then each motor unit has many fibers and very fine motor control is not possible (e.g., large, postural muscles of the back). If a muscle has many motor units then each motor unit has only a few muscle fibers and a fine degree of motor control is possible e.g., muscles of the tongue).
2. Examples - The ocular muscles have many motor units and less than 10 fibers per unit; they are capable of bringing about slight, precise movements of the eyeball.
The large gastrocnemius muscle of the calf has few motor units and as many as 1000 fibers per unit. It is perfectly suited for plantar flexing the foot in walking and running, but not for fine muscular movements.
3. Relation to the All-or-None Law of Muscle Fiber Contraction - when a motor unit fires, all the fibers of the muscle contract to the maximum that they can. This is a statement of the all-or none law of muscle fiber contraction which states that if the stimulus from a nerve to a muscle fiber goes above the "threshold stimulus", then the muscle contracts fully;
there is no such thing as a muscle contracting partially - it contracts to the fullest extent possible, or it does not contract at all.
Of course if a muscle was completely empty of ATP, you could stimulate it above threshold as much as you wanted and it would never contract- but the idea of this law is to clarify that contractile extent is not relative to stimulus strength in an individual muscle fiber - as long as you are above threshold, then you get a maximal contraction. So if a muscle that has 500 motor units has 250 of its units contract, then the muscle contracts, as a whole, to 50% of its capacity, but the fibers of the 250 motor units that did fire contracted maximally.
Another example: if a muscle has 10 motor units and 2 units fire, than the fibers of the two firing units contract maximally, but the muscle as a whole is only contracting to 20% of its capacity.
In answer to Todd and Kimberely's questions, everything I have read suggests that it not the number of synoptic knobs that increase but the consistency of the wave with regular training.
As you begin to fatigue, it is the lack of oxygen in the muscle fibres that prevents the potassium and calcium ions resynthesising ATP which prevents the muscles from further contraction.
Let me know if you anyone finds out anything different.
Sources of information:- listed web-sites above.
Thank you for the infomation refering to the questions on motor unts i asked. I have found it useful and have used the information in my essay.
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