exam 2 kinesiology
myosin
"thick" filament that consist of myosin head & tail
actin
"thin" filament that consist of troponin and tropomyosin
macrostructure of the muscles
1) Myofibrils 2) Muscle fiber 3) Fascicles 4) Muscle
what comes out of the electron transport?
ATP & water
what goes into the krebs cycle?
Acetyl CoA
what goes into electron transport?
NADH, FADH2 (krebs cycle)
lines, bands, & zones of sarcomere
ZMZ (lines) h zone IAI (bands)
contractibility
ability to contract when stimulated by action potential
excitability
ability to respond to a stimulation ("action potential") only skeletal muscle obtains
sarcomere is made up of 2 microfilaments
actin & myosin
motor unit activation
activated when the action potential is exceeding the activation threshold
sarcopenia
an age related loss of skeletal mass & strength (30% betweens ages 30 & 70)
tendon
attatches muscle belly to bone
I band & H zone
band & zone that SHORTENS during muscle contraction
I band
band with actin filament only
A band
band with myosin filament
central nervous system
brain & spinal cord
activation of muscle fibers
by "action potential" sent from the nervous system
3 types of muscles in our body
cardiac, smooth, & skeletal
sarcolemma
cell membrane of a muscle fiber
nervous system consist of 2 parts
central & peripheral (CNS & PNS)
concentric contraction
contraction in which the muscles shorten while generating force observed motion=desired effect
eccentric contraction
contraction that occurs when a force applied to the muscle exceeds the force produced by the muscle itself, results in the forced lengthening of the muscle-tendon
muscle fiber
cylinder-shaped muscle cell. contains myofibrils and organelles for ell respiration
action potential
electrochemical signal that travels down the cell membrane
type 2b
fast contraction speed large size low fatigue resistance anaerobic energy
what goes into oxidative?
fat, carbs, and protein
motor unit
function unit of muscle that consist of motor neuron group and a group of muscle fibers that it innervates
power
high rate of muscle contraction *the greater the strength the greater the power
type 2a
intermediate contraction speed intermediate size intermediate fatigue resistance aerobic-oxidative & anaerobic
type of muscle contraction
isometric, concentric, eccentric
muscle
made up of fascicles bonded together
relative strenth
max amount of a force a person can produce in a single effort relative to their body mass *negative relationship= the heavier you are the lower relative strength
anerobic power
max power produced over short term, wingate test this
factors that influence muscle performance
mental health state muscle cross-sectional area muscle fiber joint speed of movement age & sex
peripheral nervous system
moto & sensory nerves
henneman's size principle
motor units are recruited from smallest to largest to produce task-appropriate force production
fascicles
multiple muscle fibers wrapped by a thick sheath
smooth muscle
muscle of the walls of blood vessels & organs involuntary contraction very fatigue resistant
muscle performance
muscle strength (absolute & relative) power endurance
stabilizer
muscle that act to stabilize one joint so the desired movement can be preformed in another joint
antagonist
muscle that opposes the desired effect -if the desired effect is elbow flexion, triceps are the antagonist
agonist
muscle that produces the desired effect -if the desired effect is elbow flexion, biceps is the agonist or the prime movement
cardiac muscle
muscle tissue of the heart involuntary contraction very fatigue resistant
skeletal muscle
muscles supporting and moving the skeleton voluntary contraction
synergist
muscles that work together to create a movement
sliding filament theory
muscular contraction is caused by the sliding of actin filaments over myosin filaments shortens to produce tension
isokinetic contraction
production of muscle force at a constant speed allows maximum tension throughout the range of motion iso= same kinetic= motion
bands and zones
results in "striation" of the muscle
myofibrils
skeletal muscle that is composed of sarcomeres linked
type 1 fibers
slow contraction speed small in size high fatigue resistance aerobic-oxidative energy supply
endurance
the ability to resist muscle fatigue in performance -the greater the muscle strength the longer you can sustain high force production
absolute strength
the max amount of force a person can produce in a single effort *body mass is primarily muscle tissue (lean mass) *body mass correlated with strength (the heavier the stronger)
VO2
the max rate of oxegyn that can be consumed
muscle strength
the maximum force produced by the muscle
motor nerves
transmit info from CNS to skeletal muscle
sensory nerves
transmit info from sensory receptors to CNS
isometric contraction
used to stabilize a joint, such as when a weight is held at waist level neither raising nor lowering
key functions of the skeletal muscle
ventilation, heat & movement production, venous return
H zone
zone with myosin filament