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.
Describe the differences between single-unit smooth muscle and multiunit smooth muscle. Single-unit smooth muscle is found in the walls of hollow organs; multiunit smooth muscle is found in airways to the lungs and large arteries. Single-unit smooth muscle cells contract synchronously, they are coupled by gap junctions, and they exhibit spontaneous action potential.