Type of muscles:
1.- SKELETAL MUSCLES (voluntary systems)
2.- CARDIAC MUSCLE (involuntary muscle)
3.- VISCERAL-SMOOTH MUSCLES (involuntary systems)
-It provides movement for the human body-locomotion (voluntary muscles / skeletal systems).
-It permits movement of organs: involuntary muscles;
smooth and cardiac muscles.
-It maintains posture or muscle tone.
-It stabilizes joints.
-The body temperature is maintained by the production of body heat (thermogenesis)
Basic functional (contractile) unit called sarcomere.
Sarcomeres separated from each other by dark bands called Z lines.
Relaxed and contracted:
The contraction of the muscle causes the two types of myofilaments to slide toward each other and shorten the sarcomere and thus the entire muscle.
Sliding filament model: (explains mechanism of contraction)
Thick and thin myofilaments slide past each other as a muscle contracts.
Contraction requires calcium and energy-rich ATP molecules.
The muscular systems is controlled through the nervous system although some muscles (such as the cardiac muscle) can be completely autonomous.