Muscular system Flashcards
Every muscle has:
An origin
An insertion
An action
Origin site
Will be on a bone that has more mass and moves less
Insertion site
will be on a bone that has more mobility
when a muscle contracts it will pull the insertion site closer to the origin site
Tendons
Thick bands of connective tissue
muscles attach to bone via tendons
Fascia
Thin white sheets of tissue that cover muscles
Form tendons
Aponeuroses
Wider sheets of fascia
Examples: Linea alba and lumbar aponeuroses
Muscle
encased by the epimysium
composed of bundles of fascicles
Fascicle
Bundles makes up muscles
Surrounded by a perimysium
composed of bundles of muscle fibers (muscle cells)
Muscle fiber
aka muscle cell
Bundles that make up fascicles
surrounded by an endomysium
composed of bundles of myofibrils
individuals are surrounded by sarcolemma
Sacrolemma
Muscle cell membrane
lines each individual muscle fiber (muscle cell)
Epimysium
Lines muscles
Endomysium
surrounds muscle fibers
aka packing material
Myofibrils
bundles that make up muscle fibers
made up of rows of sarcomeres
Sarcomeres
continuous rows that make up myofibrils
where the chemical reactions during muscle contraction occur
Sarcoplasmic Reticulum
stores and releases calcium ions
Calcium is needed to stimulate a muscle contration