- Smooth muscle cells possess a contractile apparatus consisting of actin and myosin filaments and the cytoskeleton.
- Smooth muscle fibers usually contract slowly but are capable of sustained contractile activity.
- Locomotor skeletal muscle protein synthesis is sensitive to contractile activity and rapidly decreases within the first hours of reduced use.
- Good correlation exists between findings in vitro and the observed contractile properties in vivo.
- The contractile activity in the distal esophagus was normal with propagating contractions of appropriate amplitude and duration.