skeletal and cardiac muscle contraction differences and similarities

contraction is preceded by depolarization in the form of an action potential

propagated depolarization continues down T-tubules

excitation-contraction coupling occurs as calcium binds to troponin forming a cross bridge

cardiac muscle contraction involves pacemaker cells that are self-excitable with no neural input required

skeletal muscle contraction requires stimulation from a nerve ending

cardiac muscle contraction happens as a unit the entire heart because gap junctions allow the depolarization wave to spread

skeletal muscle contraction only the fibers that are stimulated by nerve fibers contract

cardiac muscle contraction has the depolarization wave open slow calcium channels in the plasma membrane supplying 10-20% of the calcium needed for contraction

skeletal muscle contraction receives all the calcium needed for contraction from the depolarization wave reaching the SR

cardiac muscle contraction has the absolute refractory period nearly as long as the contraction itself preventing tetanic contractions

skeletal muscle contraction has the absolute refractory period much shorter than the contraction allowing multiple contractions to summate

cardiac muscle contraction relies on aerobic respiration because the fibers have more mitochondria

skeletal muscle can utilize anaerobic respiration to contract for longer periods of time