Visco-elasticity of passive cardiac muscle.

A quantitative mechanical description of the heart organ requires information on the mechanical behavior of its muscle in reasonable unity and completeness. In this respect, a fundamental constitutive law for soft biological tissures was proposed by Fung in 1972. This article presents evidence to show that Fung's law is a useful law to describe the mechanical behavior of heart muscle in the unstimulated (diastolic) state with sufficient generality.

Mechanical properties of taenia coli smooth muscle in spontaneous contraction.

The following mechanical tests have been performed on spontaneously contracting taenia coli: isometric step stretch, isotonic step loading, and length-tension. Passive stress-strain tests have also been done. Information on spontaneous contraction was more readily obtained in isometric tests.