Skeletal Muscle Flashcards
What is the muscle belly?
Whole muscle composed of many individual muscle fibres
What are the Epimysium, perimysium and endomysium
Connective tissues that surround the muscle belly, fasciculi and muscle fibres respectively
What is the actin
Thin protein filament found in the muscle cells that together with myosin forms sarcomeres
What is the myosin?
Thick protein filament that together with actin form sarcomeres
What is the sarcomeres
The contractile units of skeletal muscle. They are composed to 2 myofilaments, actin and myosin
What is the tropomyosin
Threadlike spirals that wrap around the actin filament which covers the myosin binding site which prevents myosin attachment during the relaxed state
What is the troponin
A calcium receptor that sits on top of troponin.
In the presence of calcium it pulls tropomyosin away from the myosin binding site and allows myosin to bind to the actin filaments and the sliding filament mechanism to commence
What is the myosin cross bridge
The arm and head of the myosin filaments which extends to bind to the actin filament
What is the sarcoplasmic reticulum?
A system of membranous sacs that surrounds the myofibrilis.
The sarcoplasmic reticulum stores calcium and regulates its release during muscular contraction
What are slow twitch muscle fibres
Muscle fibre that uses oxygen to produce energy. They are associated with endurance based Activities
What are fast twitch muscle fibres?
A type of muscle fibres that has a high glycotic capacity. They are associated with speed and power based activities
What is a motor unit
The motor nerve and group of muscle fibres that it controls
All of none law?
If a motor impulse is of sufficient fibres within it will contract to their maximum possible extent
What is spatial summation
An increase in responsiveness (not done )
What is the fasciculi?
Bundle of muscle fibres that make up the muscle belly
the 5 stages of sliding filament thoery
- preparing the binding site
- power stroke
- binding of atp
- the ratchet mechanism
- return of the calcium ions back onto sarcoplasmic reticulum.
What are the 3 factors that affect the strength or force of muscle contraction - variation
- recruitment = multiple unit summation
- frequency = wave summation
- timing = synchronicity of motor unit stimulation; spatial summation
what is innervation
how the motor neuron transfers a nerve to the muscle fibers
all or none law
what are the long term physiological benifits to the neuromuscular system in resistant training
efficient and effective muscle contraction:
- recruitment of more motor units
- muscle hypertrophy
- hypertrophy of fast twitch muscle fibers
- hyperplasia of fast twitch muscle fibres- conversion type 2b to type 2a
what is the part of the brain that controls of of muscular movements
cererbellum
