Muscular System Flashcards
What are the classifications of muscles?
Cardiac, skeletal, smooth
Skeletal
Voluntary, stratified
Located in overlying skeleton
Multinucleated
Smooth
Involuntary, nonstratifed
Located in the organs or visecra
One nucleus
Cardial
Involuntary, stratified
Located in the heart, myocardium
One nucleus
Name of the muscle cell
Myocyte, muscular fiber
Every muscle is covered by a layer of?
Connective tissue/ fascia
Fascia has three layers
Epimysium (most external), perimysium (middle), endomysium (most internal)
Parts of muscular fiber
Sarcoplasmic reticulum (has calcium inside), Sarcolemma (plasmatic membrane), T-tubule
What is a fascicile?
bundle of muscle fibers, also called myocytes, bound together via the endomysium tissue that provides pathways for the passage of blood vessels and nerves.
What is inside the myofibril?
Myosin and actin (make contraction)
What is the main function of skeletal muscle?
Contraction
Thin filaments
Actin
Thick filament
Myosin
When thick and thin filaments come together it is
contracted
What does the actin and myosin need?
Calcium
What is the sliding mchanism of the filament?
1) Myosin heads make contact with actin
2)Myosin heads rotate
3)Actin is pulled to the center of the
sarcomere
What is the sliding mchanism of the filament?
1) Myosin heads make contact with actin
2) Myosin heads rotate
3) Actin is pulled to the center of the
sarcomere
4) Sarcomere shortensmuscle
contraction
When a patient has a lumbar injury
the neuron can’t stimulate the muscle
Where is the calcium stored?
Sarcoplasmic reticulum
Calcium allows
the interaction of actin, myosin, ATP
Muscles relax when
Calcium returns to SR
Skeletal muscle contraction only takes
place
when it is first stimulated by a
nerve
Where does somatic motor nerve emerge from?
Spinal chord –> skeletal muscle
Single muscle vs whole muscle
single muscle has an “all or nothing” response, but
a whole muscle can vary its force of contraction
-motor unit, recruitment