Muscle Phys Flashcards
Componets for a contraction
Action potential along efferent nerve Motor unit Calcium Ions Acetylcholine Sodium ions Potassium ions Sodium/potassium pump ATP
Neuromuscular junction componets
Synaptic knob
Synaptic vesicles
Motor end plate
Synaptic cleft
Synaptic knob
Expanded end of axon terminal
Synaptic vesicles
Tony membranous sac filled with neurotransmitter
Motor end plate
Part of sarcolemma, meets synaptic knob
Synaptic cleft
Space between motor end plate and synaptic knob
Types of contraction strength
Muscle tone, twitch, recruitment, incomplete tetanus
Factors that effect twitch strength
State of muscle tone, fatigue, muscle temperature, state of hydration, stimulus frequency
Types of contractions
Isometric, Isotonic, concentric, eccentric
Energy sources for contraction
Aerobic respiration, Anaerobic respiration, Enzyme systems, Myokinase, Creatine kinase
Aerobic respiration
- Adequate oxygen supply
- gulcose or fatty acid
- Fatty acid used for rest/low intensity exercise
Anaerobic respiration
- quick bursts of energy, short term
- Little/no oxygen required
- Lactic acid metabolized by liver
- Only two ATP for every glucose oxidized
Enzyme systems
- Phosphate group
- Short term
- One molecule equal ADP
Myokinase
Phosphate-ADP-ATP
Creatine kinase
Phosphate-creatine phosphate-ADP-ATP
Results of oxygen debt
- Rebuild creatine phosphate
- Reoxygenate muscle myoglobin
- Metabolize lactic acid in liver
- Restore body temperature
Slow twitcj
Slow oxidative, Type I, Red
Intermediate Twitcj
Type IIa, aerobic, light red
Fast Twitch
Fast glycotic, Type IIb, fast anaerobic, white
Distribution of skeletal myofiber
Contain all three
single motor unit contains only one type
slow finers dominate postural muscle
fast finers densest in eye and hand muscles
Isometric contraction
Tension generated but no change in lemgth occurs. Such as pushing against a wall.
Isotonic contraction
Tension generated and change in length occurs
Cocentric contraction
Muscle shortens as it maintains tension such as flexion
Eccentric contraction
Muscle lengthens as it maintains tension such as extension
Muscle tone
Partial contraction of resting muscle, maintains optimum distance between actin & myosin filaments, maximum contraction, regulated by CNS
Twitch
Single nerve stimulus which causes single contraction; no work done
Recruitment
Increasing strength of nerve stimulation. Frequency of stimulation occurs for more twitches to occur. Work done.
Incomplete Tetanus
Sustained fluttering of muscle; great force
