week 4 skeletal muscle Flashcards
what is the function of skeletal muscle
posture, breathing, force production , locomotion , endocrine organ, heat production
muscles are attacheted to bones by what
tendons
what is the epimysium
surrounds muscle
what is the perimysium
surround the fascicles
what is the endomysium
surrounds individual muscle fibres
what is basement membrane
just below the endomysium
what is sarcolemma
muscle membrane
what is myofibrils
contains contractile proteins
actin is what filament
thin
myosin is which filament
thicccck
what are the 5 sections of the sarcomere
Z LINE, H ZONE, A BAND, I BAN DAND M LINE
What is transverse tubules
extend from the sarcolemma to the sarcoplasmic reticulum
what is a satellite cell
cells help with growth and repair- increase nuclei in mature muscle fibres
what is the myonuclear domain
the volume of sarcoplasm surrounding nucleus
the more myonuclei means
more protein synthesis
muscle hypertrophy means a what in myonuclei
increase
how are skeletal muscles made
myoblasts fuse together
what is the NMJ made of
motor neuron and muscle fiber and motor end plate
what is the NM cleft
the gap between the muscle fiber and the neuron
what is ACETYL COA
a NT released from the motor neuron and depolarizes the muscle fibre for muscle contraction
how many muscle in the human body
600
why is the myonuclear domain important
the nucleus is responsible for gene expression in sarcoplasm
motor neurons come from where
the spinal cord and innverate muscle fibres
what part shortens during the sldiing filament
Z LINE AND SARCOMERE
Myosin attaches to where
actin on the thin filament
the release of atp causes what
the powerstroke
3 sources of atp
phosphocreatine, glycolysis, oxidative phosphorylation
what percentage average does a muscle shorten by
1%
what is the contracted mediated by
calcium
what is fatigue
a decline is power output
what causes fatigue
decrease in force production at cross bridge or and decrease in muscle shortening velocity
fatigue is effected by the type of exercise
true
1-10 intense exercise fatigue caused by what 2 things
lack of calcium release from SR, accumulation of metabolites
example of metabolites
pi, H+ and free radicles
what do pi and free radicles do
modify cross bridge reducing bridges bound to actin
what do h+ do
bind calcium binding sites on troponin , preventing calcium binding and contraction
causes of fatigue moderate intensity exercise
radicles, glycogen depletion, metabolites,
depletion of glycogen causes a decrease in what
ATP
does hydration and electrolytes impact EAMS
no
what is EAMS
exercise assosisated with muscle cramps
what is EAMS caused by
long high intensity exercise
what can is EAMS caused by
repeated electrical stimulation from hyper active motor neurons from the spinal cord
what can help EAms
STATIC STRETCHING
