Answer:
smooth muscle
Step-by-step explanation:
These are muscles found on the walls of tubular visceral organs like the blood vessels, gut, urinary tract, reproductive tract and respiratory tract. The cells that make up the smooth muscles are spindle-shaped each with a single nucleus. They contain myofibrils enclosed by a plasma membrane.
Smooth muscles are capable of slow involuntary contractions and are innervated by the autonomic part of the nervous system. The wave of muscle contarctions in the digestive tract is called peristalsis.