Skeletal Muscle: Structure and Function Flashcards
Skeletal Muscle
Muscle tissue that is under voluntary control; responsible for movement at all bodily joints
Smooth Muscle
Muscle tissue that is involuntary; Found mainly in organs and blood vessels
Cardiac Muscle
Muscle tissue that has a straited apperance and can grow as a result of exercise training
Movement of blood from one area of the body to another requires the ________ of vessels in the region where blood is needed, and __________ of the vessels in all other regions
Vasodilation (widening); vasocontriction (narrowing)
Hypertrophy
Grow larger
Atrophy
A given fiber shrinks (use it or loose it)
Myofibrils
Contractile components that allow for strenght and performance of the muscles
Myofilaments
Also known as protein filaments (actin and myosin); the cross-bridges along their length
Actin
Thin filament
Myosin
Thick filaments
Sliding filament theory
Describes the muscle contractile process; Result of a repetitive cycle of thing filaments sliding over thick filaments
Hypertrophic Protein Synthesis
Process by which actin and myosin are repaired
Z-line
End caps of the sacromere
DNA
“Free” ribosomes found floating inside cell cytoplasm
Ribosomes
Protein builders
Smallest structure to largest structure
Actin & myosin, myofibril, muscle fiber, motor unit
Red, slow twich muscle fibers
Used during a marathon/for endurance; low fatigue
Red, fast twich fibers
Used during basketball or 1 mile run; Lactate build-up is the type of fatigue
White, fast twich fibers
Used for high jump or short sprint; Fatigues quickly
Immediate Recruitment
Only the minimum number of motor units are required to move a given weight
Depleting Energy Recruitment
Each repeition will slowly deplete the working motor units of energy
Contractile Speed Recruitment
Maximum contraction against a submaximal resistance (less than what the individual is capable of)
Three reaons a muscle fiber stops contracting
Myofibril failure; intermediate failure; mitchondrial failure
Myofibril failure
Failure that occurs if the resistance is so great that contractile components fail; causes the greatest amount of muscle damage; failure at 4 to 6 rep range