Muscles Flashcards
Contractility
shortens in length, moves body part
Excitability
responds to a stimulus
Extensibility
it can be stretched
Elasticity
it returns to original length
What are the functions of the muscular system?
Body movement, heat production, posture, stabilizes joints, open/close body passageways, medical
What is the difference between the origin and insertion of a muscle?
Origin: attaches to stationary bone, usually proximal
Insertion: attaches to moveable bone, usually distal
what are the types of tendons
Aponeuroses: flat, sheetlike
Tendon sheaths: modified bursa wrapped around tendon
Retinaculum: band around group of tendons
what are the associated connective tissues?
epimysium (outermost), perimysium, and endomysium (innermost)
What is the function of the associated connective tissue?
Endomysium: insulates individual muscle fibers
Perimysium: insulates a bundle of muscle fibers
Epimysium: continues with tendon, surrounds a bundle of fascicles
What are synergistic and antagonistic muscles?
Synergistic: muscles that cross the same joint, contract together, have similar actions
Antagonistic: opposite functions, usually opposite sides
How are skeletal muscles named?
Direction, size, location, association with bones, origin and insertion, shape, action
What does the motor unit consist of?
One neuron and multiple muscle fibers
How do motor units vary among muscles?
Smaller units = finer control
Larger muscles need more motor units
What principle does the fibers obey?
All-or-none principle
