muscle physiology- muscle fibers, contractions, exercises

all muscle fibers regulated by a sign neuron is called what

motor unit

what is muscle tone

the lowest level of contraction or how ready your muscle is to contract at it’s resting stage

isotonic contraction

lead to movement

types of isotonic muscles

concentric contractions, force is generated as the muscle shortens

eccentric contractions, force is generated as the muscle elongates

isometric contractions

do not lead to movement

what is a muscle twitch

the response of a muscle to a single stimulation

what are the three phases of a muscle twitch and what occurs during each period

the latent period - when excitation-contraction coupling first begins

the period of contraction - cross bridges are actively forming and causing tension

the period relaxation - as calcium is pumped back into the sarcoplasmic reticulum, active cross bridges decline

what happens during summation stimulation

new stimulus occurs during the relaxation phase of previous stimulus

messages “added” together

what happens during tetanus stimulation

stimulus frequency is so high, the relaxation phase disappears completely

continuous contractions

what are ways the strength of a muscle contraction increases

more motor units

multiple motor units responding

recruits more muscle fibers

increases motor unit

what are the three types of muscle fibers

fast glycolytic fibers ( fast ATP use/ glycolysis (anaerobic) )

fast oxidative fibers ( fast ATP use/ oxidative phosphorylation (aerobic) )

slow oxidative fiber ( slow ATP use/ oxidative phosphorylation (aerobic) )

overload principle

states that muscles will adapt and grow when they are forced to work harder than before

they can become larger (hypertrophy)

they can become more efficient / stronger

what is the main different between male and female strength or skeletal muscle

males generally have more muscle mass which lead to stronger contractions

fast glycolytic fibers (exercise and its effects on the fiber)

-resistance/weight training

-size of individual muscle fibers increases

-size of muscle increases

-amount of stored glycogen increases '

-hypertrophy (increase size) of skeletal muscle

slow oxidative fibers (exercise and its effects on the fiber)

aerobic/endurance exercise

-blood flow to muscles increases

-number of mitochondria increases

-amount of myoglobin increases

-fibers have greater strength, endurance, and fatigue resistance

fast oxidative fibers (exercise and its effects on the fiber)

sarcopenia

normal age-related decline in the number of muscle fiber

The remaining muscle fibers are smaller and less elastic

-they cannot tolerate as much physical strain'

-they’re less able to recover from injuries