L2 - producing, controlling and maintaining Force and Power Flashcards
Describe the factors affecting muscular force.
Factors include proprioceptive information, ATP and Phosphocreatine availability, and intrinsic muscle properties.
Explain the components of muscle structure.
Muscle structure includes muscle fibers, myofibrils, sarcomeres, z lines, and m bands, with numerous contractile proteins
what are the factors effecting torque?
muscle force, antagonist and tendon structure and insertion.
What is required to initiate muscle contraction at neuromuscular junctions?
Excitation is required to initiate contraction.
What role does inadequate integration at the neuromuscular junction play in aging?
It can lead to a loss of integrity, which is a component of muscle loss seen in aging.
How can comprehensive gym prescriptions help prevent muscle loss?
By utilizing various exercises, comprehensive gym prescriptions ensure muscle retention and help prevent muscle loss.
What triggers the release of Ca++ from the sarcoplasmic reticulum (SR) in muscle cells?
The nerve impulse travels down T-tubules and causes the release of Ca++ from the SR.
What happens when Ca++ binds to troponin in muscle cells?
Ca++ binding to troponin causes a position change in tropomyosin, which exposes active sites on actin.
How does the exposure of active sites on actin contribute to muscle contraction?
It permits a strong binding state between actin and myosin, leading to muscle contraction.
What role does ATP play in the contraction of muscle fibers?
ATP binding to the myosin head weakens its binding to actin, facilitating the detachment of myosin from actin and allowing for muscle relaxation.
what is the size principle
motor neurons recruited progressively by axon size, small to large. As the smaller axons reach threshold first.
How are motor units categorised.
In functionally, fast, slow twitch, force produced and how fatigued.
two benefits of the size principle.
use fatigue-resistant units longer, as slow twitch fibres are always going.
finer regulation with low force, as the slow fibres are always on with low force. bring in the big ones when needed.
what is fatigue
Fatique is you are reducted in strength regardless whether we see a reduction in performance. is hardly ever CNS or PNS but the interaction of them both.
As the CNS will limit motor output when it is major.
what is the central governor model.
something that predicts that the performance during endurance events is set by the subconscious brain specifically to ensure that the athlete reaches the finish line while still in physiological homeostasis.
rigimortis
cannot release the myosin and actin from each other.
how can fatigue affect your atp and glycogen?
you can fatigue with the anticipatory behavioural regulation with no or little ATP depletion and still some glycogen in muscle. As force is depleted before either ATP or glycogen can become depleted.
at different altitudes what drives fatigue
Low altittive - muscle drives fatigue
High altittude - brain drives fatigue
three ways by which excess acidity can mediate fatiqgue
decrease calcium release from SR. decrease binding of calcium to troponin. and decrease x-bridge directly.
length tension in muscle.
longer fibre and msucles, less CSA will give rapid shorting. shorter fibre/muscle more CSA gives greater force capacity.
movements that produce most force.
eccentric > isometric > concentric.
upper body and lower body strenght women vs men
upper men around 50% > women.
lower men around 30% > women.
why loss of muscles and strength with aging (6)
loss of growth related hormones
decrese IGF-1 (so less of: protein production and breakdown)
atrophy
sacropenia (= active loss of muscles)
accumlate fat and denervated fibres in muscles
nerve conduction velocity decrese
