The sternothyroid muscle is known as the sternum thyroid muscle . It is a muscle that belongs to the muscles of the hyoid bone . This is called the infrahyal muscles.

The sternothyroid muscle is a small muscle that runs from the breastbone to the top of the larynx. He is significantly involved in the implementation of the human swallowing act. As soon as the muscle fibers of the sternothyroid muscle contract, the hyoid bone moves down. At the same time, the larynx is also moved downwards. This process occurs at the moment when the swallowing reflex begins. This clears the way to the stomach . This process is no longer subject to voluntary control, even if the preparations for swallowing are controlled and planned.

Anatomy & Structure

The sternothyroid muscle is a striated muscle. This means that the muscle fibers of the muscle have an arrangement in which they repeat periodically.This gives a certain pattern. It is formed by cross stripes. The sternothyroid muscle arises from the manubrium sterni. This is part of the breastbone. It is located cranial, i.e. at the top, and forms the widest part of the breastbone. This is called the sternum in medicine. The sternum connects to the collarbone . The larynx is called the larynx. It consists of fibers and cartilage and is set in motion by various muscles. The larynx has a vertical shape and is surrounded by different layers of cartilage.

They include the thyroid cartilage , the cricoid cartilage , the arytenoid cartilage , and the epiglottis cartilage. The thyroid cartilage is called the thyroid cartilage. The sternothyroid muscle runs from the sternum below the sternohyoid muscle. Its way goes to the thyroid cartilage, which it sets in motion. The sternothyroid muscle is innervated by the ansa cervicalis . This is a nerve pathway made up of various fibers from the cervical plexus and spinal cord .

Function & Tasks

The sternothyroid muscle, together with other muscles in the mouth and throat area, is responsible for the functional activity of swallowing . During the act of swallowing, the pharynx first rises and then falls. At the same time, the trachea is closed so that the liquids, food and saliva produced in the mouth can be channeled directly into the esophagus and down to the stomach .

The act of swallowing is considered to be very complex. Various muscles work closely together so that this can run smoothly. The swallowing process is divided into a deliberately controlled and an automatic process. The preparations, such as crushing the food or the supply of liquids are part of the deliberately controlled process. They initiate the act of swallowing. The ingested substances are pushed deep into the throat. The functionality of the tongue plays an important role here. Once there, the swallowing reflex is automatically initiated.

During this process, the trachea is closed and the base of the tongue is raised. This pushes food, saliva and liquids deeper down the throat. So that they can also drain off, the hyoid bone lowers downwards. At the same time, the larynx also sinks. The activity of the sternothyroid muscle causes the hyoid bone and the upper cartilage of the larynx to lower. It thus makes a significant contribution to a well-functioning swallowing act.

Diseases

Diseases that affect the activity of the sternothyroid muscle include those whose symptoms range from the mouth to the larynx. These can be inflammatory diseases, paralysis, swelling, tissue regeneration and infections.Inflammation and infections cause problems with the act of swallowing. In the case of paralysis or a cramp, the swallowing process can no longer be carried out. Swelling includes enlargement of the tonsils or lymph . They close the entrance to the throat and narrow the esophagus. Sleep disorders such as sleep apnea cause breathing to stop. The muscles relax spontaneously while the human consciousness is not active. New growths, such as edema or cysts in the entrance to the throat up to the larynx, contribute to a narrowing of the canal between the pharynx and the upper larynx area.

The formation of a carcinoma significantly impairs the functioning of the larynx. Accidents or falls that involve the throat have an immense impact on swallowing and phonotony. Since the larynx is surrounded by a cartilage framework, it does not have the necessary protection as soon as the neck is narrowed from the outside. A throat constriction not only affects the act of swallowing. In addition, the air supply is restricted or suspended.

In the event of an emergency or the rescue of a human being, in some cases emergency care can be provided by supplying oxygen. For this procedure, a tracheotomy is performed and intubated. Depending on the situation, this can lead to injuries to the cartilage structure on the larynx. In medicine, this is referred to as a trauma. Trauma can also occur when a patient needs to be intubated for an extended period of time. In addition, anything that attacks the neck and throat area is harmful. This includes smoking , as well as inhaling toxic gases.