T9 Locomotion Flashcards
Skeletal muscle
functions to contract in response to a stimulus.
Muscle
bundle of muscle fibres (muscle cells)
Myoblasts fuse
to form long multi-nucleate cell
Myofibrils
basic rod-like organelle of a muscle cell (consist of alternating myosin and actin in stacks)
Myosin
thick filaments
Actin
thin filaments
Sarcomeres
unit of skeletal muscle, arrangement of thick and thin filaments along length of myofibril
Sliding filament model
model of muscle contraction that shows how muscles generate force and produce movement
Muscles contract
when the myosin filaments pull the opposing actin filaments toward each other
Cross Bridge Cycle
as myosin attaches to actin, myosin pulls of actin, ATP is generated and myosin detaches, Atp is hydrolyzed
Force is generated
when number of cross-bridges between actin & myosin in sarcomere increase
more muscle cells/fibres
more sarcomeres
longer muscle cells/fibres
more sarcomeres
rapid contraction
decreases number of cross-bridges
Physiological limitations on energy production
limit rate of ATP production, delivery of O2 to muscles (takes time)
Aerobic oxidative respiration
Slow Twitch (Type I)
High mitochondria
Slow Twitch (Type I)
High myoglobin (stores O2)
Slow Twitch (Type I)
High vascularization
Slow Twitch (Type I)
Low glycogen
Slow Twitch (Type I)
Low power, endurance
Slow Twitch (Type I)
Dark meat
Slow Twitch (Type I)
Anaerobic glycolysis
Fast Twitch (Type II)
Low mitochondria
Fast Twitch (Type II)
Low myoglobin
Fast Twitch (Type II)
Low vascularization
Fast Twitch (Type II)
High glycogen
Fast Twitch (Type II)
High power, bursts
Fast Twitch (Type II)