action force definition, action force meaning | English dictionary. action. 7 the operating mechanism, esp. in a piano, gun, watch, etc. n (Physics) the supposed interaction of two separated bodies without any intervening medium.
The myometrium is the middle layer of the uterine wall, consisting mainly of uterine smooth muscle cells (also called uterine myocytes), but also of supporting stromal and vascular tissue. Its main function is to induce uterine contractions.
Smooth muscle is found within the walls of blood vessels (such smooth muscle specifically being termed vascular smooth muscle) such as in the tunica media layer of large (aorta) and small arteries, arterioles and veins. In smooth muscle, there is a single gene (MYH11) that codes for the heavy chains myosin II, but there are splice variants of this gene that result in four distinct isoforms. 2  Also, smooth muscle may contain MHC that is not involved in contraction, and that can arise from multiple genes.