for peristallysis
The esophagus has two types of muscles. The upper third of the esophagus is composed of striated muscles, while the lower third contain smooth muscles. The muscles in the middle are a mixture of both striated and smooth.
the radial fibers contract,enlarging the pupil and allowing more light to enter the eye
Circular and Radius set of muscle fibers
Smooth Muscle Fiber
Muscle fibers can be smooth or striated. Smooth muscle is often involuntary and line the blood vessels and gastrointestinal tract. Striated muscles may be voluntary, such as skeletal muscle, or involuntary such as cardiac muscle.
The body of the esophagus is bounded by physiologic sphincters known as the upper and lower esophageal sphincters. The upper sphincter is composed largely of a muscle that is closely associated with the larynx. When relaxed, as it is during swallowing, this muscle pulls the larynx forward and aids in routing food into the esophagus instead of the larynx. The lower sphincter is simply the muscle that surrounds the esophagus just as it enters the stomach. Both the upper and lower sphincter are closed except during swallowing, which prevents constant entry of air from the oral cavity or reflux of stomach contents.
There are two broad types of voluntary muscle fibers: slow twitch and fast twitch. Slow twitch fibers contract for long periods of time but with little force while fast twitch fibers contract quickly and powerfully but fatigue very rapidly.
Muscle fibers can be arranged into two basic structural patterns, fusiform and pinnate. Most human muscles are fusiform, with the fibers largely arranged parallel along the muscle's longitudinal axis. In many of the larger muscles the fibers are inserted obliquely into the tendon, and this arrangement resembles a feather. The fibers in a pinnate (feather) muscle are shorter than those of a fusiform muscle. The arrangement of pinnate muscle fibers can be single or double, as in muscles of the forearm, or multipinnate, as in the gluteus maximus or deltoid.
The esophagus is a muscular tube that contracts in a wave-like motion to push food from the mouth to the stomach, a process called peristalsis. It has two types of muscle layers, circular and longitudinal, that work together to propel the food downward. The lower esophageal sphincter at the entrance to the stomach prevents the backflow of stomach contents into the esophagus.
There are two types of muscle in the body. The Cardiac Muscle and the Skeletal Muscle. The skeletal muscle is made up of intrafusal and extrafusal fibers. The Muscle Belly is made up entirely of extrafusal fibers (even in the deepest parts). The intrafusal fibers are located throughout the muscle. The cardiac muscle is distinct from skeletal muscle, one of the main differences is the amount of mitochondria it has is increased, and so technically at the deepest part of cardiac muscle is mitochondria (but there are other components as well).
Muscle fibers, or muscle cells, are made up of two kinds of fibers, or myofilaments. The thin ones are called actin, and the thick ones are called myosin.
This word can be broken down into two parts that will reveal the answer to your question. Myo is the medical term for muscle and cardio is the medical term for heart. Therefore, your answer would be the muscle that is the heart.