Logan Steele
The cricopharyngeal muscle is a crucial component of the inferior constrictor muscle, which is made up of two parts: the thyropharyngeal and the cricopharyngeal. The cricopharyngeal muscle is supplied by the recurrent and external laryngeal nerves, which are branches of the vagus nerve. It is also innervated by the recurrent laryngeal nerve (RLN), as demonstrated by studies on adult sheep and human cadavers. The RLN supplies the muscles of the larynx and is essential for swallowing. The cricopharyngeal muscle acts as an upper oesophageal sphincter, keeping the oesophageal inlet closed except during swallowing or vomiting. It is responsible for the high-pressure zone within the EI muscles, which include the inferior pharyngeal constrictor, cricopharyngeus, and cervical oesophagus.
| Characteristics | Values |
|---|---|
| Part of | Inferior pharyngeal constrictor muscle |
| Consists of | Two parts: thyropharyngeal and cricopharyngeal |
| Cricopharyngeal part origin | Anterolateral parts of cricoid cartilage |
| Cricopharyngeal part composition | Pars oblique (superior part) and pars fundiformis (inferior part) |
| Cricopharyngeal nerve | Cricopharyngeal nerve |
| Innervation | Recurrent laryngeal nerve |
| Length | 3 cm to 5 cm |
| Function | Aids in the closure of the upper oesophagus |
Explore related products
What You'll Learn
- The cricopharyngeus muscle is supplied by the recurrent and external laryngeal nerves
- The muscle is also supplied by the pharyngeal branch of the ascending thyroid artery
- The cricopharyngeus is the main component of the upper oesophageal sphincter
- It is responsible for the high-pressure zone within the EI
- The cricopharyngeus muscle is involved in the closure of the upper oesophagus
The cricopharyngeus muscle is supplied by the recurrent and external laryngeal nerves
The cricopharyngeus muscle is a crucial component of the inferior constrictor and the upper oesophageal sphincter. It is responsible for keeping the oesophageal inlet closed, except during swallowing. The cricopharyngeus muscle is supplied by the recurrent and external laryngeal nerves.
The recurrent laryngeal nerve (RLN) is a major nerve that supplies the muscles of the larynx, including the cricopharyngeus muscle. Studies have shown that the RLN innervates the cricopharyngeus muscle, with a nerve branch leading from the RLN to the muscle. Electrical stimulation of the RLN has been observed to elicit a muscle action potential in the cricopharyngeus muscle. This was demonstrated in a study by Hammond, Carol Smith, Paul W. Davenport, Alastair Hutchison, and Randall A. Otto, published in the Journal of Applied Physiology in 1997.
The cricopharyngeus muscle is also supplied by the external laryngeal nerve, which is a branch of the vagus nerve. The vagus nerve provides additional innervation to the cricopharyngeus muscle via its branches, including the external laryngeal nerve. This complex network of nerves ensures the proper functioning of the cricopharyngeus muscle during various physiological processes, such as swallowing.
The cricopharyngeus muscle is an important muscle in the upper oesophageal sphincter, and its function is to maintain a sustained tonic contraction to permit a basal muscular tone. This muscle must also be able to rapidly relax, as required during swallowing or vomiting. The coordination of contraction and relaxation in the cricopharyngeus muscle is essential for normal physiological processes.
The cricopharyngeus muscle is a complex muscle with a vital role in the human body. Its innervation by the recurrent and external laryngeal nerves highlights the importance of these nerves in maintaining the proper functioning of the muscle. Dysfunction of the cricopharyngeus muscle can lead to conditions such as dysphagia, and various interventions are available to manage these disorders.
Muscle Bruises: Swelling and What to Expect
You may want to see also
Explore related products
The muscle is also supplied by the pharyngeal branch of the ascending thyroid artery
The cricopharyngeal muscle is part of the inferior pharyngeal constrictor muscle. The inferior pharyngeal constrictor muscle is supplied by the pharyngeal branch of the ascending thyroid artery and muscular branches of the inferior thyroid artery. The inferior thyroid artery is considered the principal blood supplier of the thyroid gland. The inferior pharyngeal constrictor muscle consists of two parts: the thyropharyngeal and the cricopharyngeal. The cricopharyngeal part of the inferior pharyngeal constrictor muscle originates from the anterolateral parts of the cricoid cartilage. It is further divided into two parts: the pars oblique (superior part) and the pars fundiformis (inferior part).
The pars oblique is oriented posteromedially, inserting onto the median pharyngeal raphe. The pars fundiformis courses horizontally, forming a semicircular band that fuses with the circular muscle fibres of the proximal oesophagus. The cricopharyngeal muscle is the main component of the upper oesophageal sphincter, and the failure of its coordinated relaxation or expansion is termed cricopharyngeal muscle dysfunction (CPD).
The pharyngeal branch of the ascending thyroid artery is important in the context of the cricopharyngeal muscle, as it supplies blood to this muscle. The ascending thyroid artery is a branch of the thyrocervical trunk, specifically the third branch, known as the inferior thyroid artery (ITA). The ITA gives rise to several other arteries, including the ascending cervical artery and the inferior laryngeal artery. It also supplies the four parathyroid glands.
The pharyngeal branch of the ascending thyroid artery plays a crucial role in providing oxygenated blood to the cricopharyngeal muscle, ensuring its proper function and maintaining the overall health of the upper oesophageal sphincter.
Muscle Tearing: Signs, Symptoms, and Recovery
You may want to see also
Explore related products
The cricopharyngeus is the main component of the upper oesophageal sphincter
The cricopharyngeus muscle (CPM) is a sphincter muscle that encircles the upper end of the oesophagus, also known as the upper oesophageal sphincter (UES). It is a closure muscle that is almost always in a contracted state, even during sleep. Its action is like a continually clenched fist, closing off the entrance to the oesophagus.
The UES is a critical component of the airway protective mechanism, guarding the entrance of the oesophagus and controlling inflow and outflow through the region. It separates the oesophagus from the pharynx and larynx, preventing aerophagia in the anterograde direction and regurgitation in the retrograde. The UES is opened intermittently by the relaxation of its sphincteric muscles, including the CPM, which allows food or liquid to pass through and enter the oesophagus.
The CPM is structurally, biochemically, and mechanically distinct from surrounding pharyngeal and oesophageal muscles, except for the inferior pharyngeal constrictor (IPC). It attaches to the dorsolateral aspect of the lower part of the cricoid cartilage, forming a horizontal muscular band. In humans, two sets of muscle fibres have been identified: the horizontally oriented fibres (CPh), pars fundiformis, and an oblique band of fibres (CPo), pars obliqua. The pars fundiformis of the CPM has no median raphe.
The cricopharyngeus is the main component of the UES, although it is often considered synonymous with the UES, it is just one component of a complex anatomy. The UES is composed of three muscles: the cervical oesophagus, cricopharyngeus, and inferior pharyngeal constrictor, but the cricopharyngeus is the primary muscle. The inferior pharyngeal constrictor consists of two parts: the thyropharyngeal and cricopharyngeal. The cricopharyngeal part originates from the anterolateral parts of the cricoid cartilage and is further divided into two parts: pars oblique (superior part) and pars fundiformis (inferior part).
The Intriguing Names of Muscles and Their Actions
You may want to see also
Explore related products
It is responsible for the high-pressure zone within the EI
The cricopharyngeus muscle is a vital component of the upper oesophageal sphincter, which is formed by the cricopharyngeal muscle and the inferior pharyngeal constrictor. The cricopharyngeus muscle is responsible for maintaining the oesophageal inlet closed, except during the act of swallowing. This muscle is innervated by the recurrent laryngeal nerve and branches of the vagus nerve.
The cricopharyngeus muscle is also known as the CPM, and it is the most inferior pharyngeal muscle. It is attached to the thyroid and cricoid cartilages, with its fibres transitioning to the circular fibres of the oesophagus. The CPM plays a crucial role in swallowing by relaxing and allowing the pharyngeal pressure to propel a bolus through the open sphincter. This process is facilitated by the CPM's ability to rapidly relax while still maintaining a sustained tonic contraction to keep the sphincter closed when not swallowing.
The high-pressure zone within the EI (esophageal introitus) is specifically attributed to the cricopharyngeus muscle. The EI muscles include the inferior pharyngeal constrictor, cricopharyngeus, and cervical oesophagus. The cricopharyngeus muscle is the primary component of these closure muscles, and its sustained contraction creates the high-pressure zone. This high pressure ensures that the oesophageal inlet remains closed, preventing any unwanted passage of food or liquid when swallowing is not occurring.
The length of the EI ranges from 3 cm to 5 cm, and it is located at the upper end of the oesophagus, which itself is part of the gastrointestinal tract connecting the pharynx to the stomach. The EI is a critical region for maintaining the pressure gradient necessary for effective swallowing and preventing any regurgitation of food or liquid. The EI's closure muscles, including the cricopharyngeus, are responsible for this crucial function.
The cricopharyngeus muscle is susceptible to various conditions, including cricopharyngeus muscle dysfunction (CPD). CPD can manifest with symptoms ranging from asymptomatic to severe dysphagia. Interventions for CPD include nonsurgical procedures such as pharyngoesophageal segment dilation, botulinum toxin injection, and cricopharyngeal myotomy. Maintaining the health and function of the cricopharyngeus muscle is essential for preserving the high-pressure zone within the EI and ensuring safe and efficient swallowing.
Muscle Spasms: Understanding the Uncomfortable and Painful Feeling
You may want to see also
Explore related products
The cricopharyngeus muscle is involved in the closure of the upper oesophagus
The cricopharyngeus muscle is a crucial component of the upper oesophageal sphincter (UES), a group of muscles that includes the inferior pharyngeal constrictor and the cervical oesophagus. The UES is responsible for preventing esophageal air insufflation during negative intrathoracic pressure events, such as inspiration, and stopping esophagopharyngeal/laryngeal reflux during esophageal peristalsis.
The cricopharyngeus muscle is a sphincter muscle that encircles the upper end of the oesophagus, and it is almost always in a contracted state, even during sleep. This contraction effectively closes off the entrance to the oesophagus, much like a clenched fist. The UES is opened when the cricopharyngeus muscle relaxes, allowing food or liquid to pass through and enter the oesophagus. This relaxation occurs during swallowing or vomiting, and it is essential for the passage of food and liquids.
The cricopharyngeus muscle is subject to two main disorders: cricopharyngeal dysfunction and cricopharyngeal spasm. Cricopharyngeal dysfunction is the failure of the muscle to relax, resulting in swallowing difficulties. On the other hand, cricopharyngeal spasm is a hyper-contraction of the muscle, causing a sensation of a lump in the throat without interfering with swallowing.
The muscle is innervated by branches of the vagus nerves and the recurrent laryngeal nerve. It is supplied by the pharyngeal branch of the ascending thyroid artery and muscular branches of the inferior thyroid artery. The cricopharyngeus muscle plays a vital role in maintaining the high pressure within the upper oesophageal sphincter, and its proper function is essential for the normal passage of food and liquids during swallowing.
Muscle Therapists: Healing Through Touch
You may want to see also
Frequently asked questions
The cricopharyngeal muscle is a muscle located in the inferior constrictor that serves as the primary component of the upper oesophageal sphincter.
Its primary function is to keep the oesophageal inlet closed, except during swallowing.
The cricopharyngeal muscle is supplied by the recurrent and external laryngeal nerves.
The length of the cricopharyngeal muscle is about 3 cm to 5 cm.
Swallowing is accomplished when the cricopharyngeal muscle relaxes, and pharyngeal pressure is sufficient to propel a bolus through the open sphincter.
