The trachealis muscle is a sheet of smooth muscle in the

trachea The trachea (: tracheae or tracheas), also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all animals' lungs. The trachea extends from ...

Structure

The trachealis muscle lies posterior to the

and anterior to the oesophagus. It bridges the gap between the free ends of C-shaped rings of cartilage at the posterior border of the

, adjacent to the oesophagus. This completes the ring of cartilages of the trachea. The trachealis muscle also supports a thin cartilage on the inside of the trachea. It is the only smooth muscle present in the trachea.

Function

The primary function of the trachealis muscle is to constrict the trachea, allowing air to be expelled with more force, such as during

cough A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and Microorganism, microbes. As a protective reflex, coughing can be repetitive with the cough reflex fol ...

ing.

Clinical significance

Tracheomalacia may involve

hypotonia Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but it is a potential manifestation of many different dis ...

of the trachealis muscle. The trachealis muscle may become stiffer during

ageing Ageing (or aging in American English) is the process of becoming older until death. The term refers mainly to humans, many other animals, and fungi; whereas for example, bacteria, perennial plants and some simple animals are potentially biol ...

, which makes the whole trachea less elastic. In infants, the insertion of an oesophagogastroduodenoscope into the oesophagus may compress the trachealis muscle, and narrow the trachea. This can result in reduced airflow to the lungs. Infants may be intubated to make sure that the trachea is fixed open.

References

{{Authority control Respiratory system Respiration

Structure

Function

Clinical significance

See also

References