Muscle Fibres to Sliding Filament Theory Flashcards
What are the common features of muscles?
Nervous control, contractility, extensibility, elasticity, atrophy, and hypertrophy.
What is nervous control in muscles?
Nerve stimuli control muscle action.
What is contractility?
Muscles contract and become thicker.
What is extensibility?
Muscles can stretch when a force is applied.
What is elasticity in muscles?
Muscles return to their original size and shape once stretched.
What is atrophy?
Decrease in muscle size due to injury, illness, or lack of exercise.
What is hypertrophy?
Increase in muscle size with increased activity.
What are fusiform muscles?
Fibres run the length of the muscle belly, designed for mobility, producing contractions over a large range with low force.
What are pennate muscles?
Fibres run at angles to the tendons, designed for strength and power.
What are convergent muscles?
Fibres radiate from the main tendon, combining strength, power, and mobility.
What are unipennate muscles?
Fibres on one side of the central tendon, e.g., semimembranosus.
What are bipennate muscles?
Fibres on both sides of the central tendon, e.g., rectus femoris.
What are multipennate muscles?
Fibres branch out from several tendons, e.g., deltoid.
What is epimysium?
Connective tissue covering skeletal muscle.
What is endomysium?
Connective tissue surrounding each muscle fibre.
What is perimysium?
Connective tissue binding fasciculi together.
What is sarcoplasm?
Gel-like fluid in muscle fibres containing mitochondria, myoglobin, and ATP.
What is a sarcomere?
The contractile unit of a muscle fibre.
What is the sliding filament theory?
Muscle contraction occurs as actin and myosin filaments slide past each other. A neural impulse arrives at the neuromuscular junction releasing calcium, allowing myosin to bind with actin.
What are Type 1 muscle fibres?
Slow-twitch oxidative fibres, suited for endurance activities.
What are Type 2A muscle fibres?
Fast-twitch oxidative fibres, suited for middle-distance running and swimming.
What are Type 2B muscle fibres?
Fast-twitch glycolytic fibres, suited for high-intensity, short-duration activities.
