The driving age should be raised up to 18 because teens can be a little careless. Driving at the age of 18 is a more mature age for teens because they can have more responsibility. Teens should not be driving at the age of 16 because they could be texting and driving or drinking and driving with some friends.
During contraction, the smooth-muscle cell's intermediate filaments help to draw the cell up, like closing a drawstring purse. Calcium ions regulate contraction in smooth muscle, but they do it in a slightly different way than in skeletal muscle: Calcium ions come from outside of the cell. Calcium ions bind to an enzyme complex on myosin, called calmodulin-myosin light chain kinase.
3 types of muscles: 1) Smooth muscle-controlled by the autonomic nervous system; may either be generally inactive and then respond to neural stimulation or hormones or may be rhythmic. 2) Cardiac muscle-found in the heart, acts like rhythmic smooth muscle, modulated by neural activity and hormones. types of muscles: 1) Smooth muscle-controlled by the autonomic nervous system; may either be generally inactive and then respond to neural stimulation or hormones or may be rhythmic. 2) Cardiac muscle-found in the heart, acts like rhythmic smooth muscle, modulated by neural activity and hormones.