Exclusively breastfed babies do not require additional water even when it is very hot outside, as long as baby is allowed to nurse as needed. Even in extremely hot, dry weather your baby can get all the liquids needed via breastmilk.
Smooth muscles contract very slowly, whereas skeletal muscles can contract at different rates. Skeletal muscles can be composed of fast-contracting fibers, slow-contracting fibers or a mixture of both.
While most of the processes are similar, there are some notable differences between the actions of skeletal, cardiac and smooth muscle. Cardiac-muscle cells are striated, and are a lot like skeletal-muscle cells except that in cardiac muscle, the fibers are interconnected.