T1 U9 Skeletal muscle activity Flashcards
What are the functional characteristics of skeletal muscle
Excitability
Contractility
Extensibility
Elasticity
What is a motor unit
One neuron + all skeletal muscle cells
Name the path a stimulus travels
Axon -> Axon terminal -> Neuromuscular junction -> Vesicles -> Neurotransmitter -> ACH
Name the order of the 4 phases of Skeletal muscle contraction
Cross-bridge attachment
Working / power stroke
Cross-bridge detachment
Cocking myosin head
Explain sliding filament theory
Muscle fibres activated and myosin heads attach to binding sites and sliding begins
Each attachment and detachment causes tension generation which helps pull thin filaments toward centre of sarcomere
Cell shortens but not myofilaments
Describe the graded response contraction
Whole muscle reacts to stimuli in 2 ways
- change frq of muscle stimuluation
- Change number of muscle cells stimulated at one time
3 ways of ATP regeneration
1) direct phsoporylation
2) aerobic respiration
3) Anaerobic glycolysis
What causes muscle fatugue
Strenuous or prolonged exercise. Occur b/c O2 deficit causing lactic acid build up causing a decrease in ATP
Effects of Aerobic execise
Incr. blood supply
Incr. metabolism
heart enlarges
more efficient lungs
Effects of Resistance execise
Incr. muscle size + strength
Incr. muscle cell size