Inferior pharyngeal constrictor muscle: Difference between revisions

Latest revision as of 02:48, 11 December 2024

The inferior pharyngeal constrictor muscle is one of the three pharyngeal constrictor muscles that form the muscular wall of the pharynx. It plays a crucial role in the process of swallowing by constricting the pharyngeal cavity and propelling the bolus of food from the oropharynx to the esophagus.

Anatomy[edit]

The inferior pharyngeal constrictor muscle is the thickest of the pharyngeal constrictors and is located in the lower part of the pharynx. It is composed of two parts:

The thyropharyngeal part, which originates from the oblique line of the thyroid cartilage.
The cricopharyngeal part, which originates from the lateral aspect of the cricoid cartilage.

Both parts insert into the pharyngeal raphe, a fibrous seam that runs along the posterior midline of the pharynx.

Function[edit]

The primary function of the inferior pharyngeal constrictor muscle is to facilitate swallowing. During the act of swallowing, the muscle contracts sequentially with the other pharyngeal constrictors to constrict the pharyngeal cavity, pushing the food bolus downward into the esophagus. The cricopharyngeal part acts as a sphincter at the top of the esophagus, preventing air from entering the esophagus during breathing and preventing reflux of esophageal contents.

Innervation[edit]

The inferior pharyngeal constrictor muscle is innervated by the pharyngeal plexus, which is primarily composed of fibers from the vagus nerve (cranial nerve X). The cricopharyngeal part also receives some innervation from the recurrent laryngeal nerve, a branch of the vagus nerve.

Blood Supply[edit]

The blood supply to the inferior pharyngeal constrictor muscle is primarily from the ascending pharyngeal artery, a branch of the external carotid artery.

Clinical Significance[edit]

Dysfunction of the inferior pharyngeal constrictor muscle, particularly the cricopharyngeal part, can lead to swallowing disorders such as dysphagia. Cricopharyngeal achalasia, a condition where the cricopharyngeal muscle fails to relax properly, can cause difficulty in swallowing and may require medical or surgical intervention.

Also see[edit]

Gallery[edit]

Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves.
Sagittal section of the pharynx, showing the pharyngeal constrictor muscles.
Lateral view of the pharynx, highlighting the inferior pharyngeal constrictor muscle.

Template:Muscles of the head and neck

@@ Line 1: / Line 1: @@
-== Inferior Pharyngeal Constrictor Muscle ==
+{{Infobox muscle
+| Name         = Inferior pharyngeal constrictor muscle
+| Latin        = Musculus constrictor pharyngis inferior
+| Image        = Musculusconstrictorpharyngisinferior.png
+| Caption      = Inferior pharyngeal constrictor muscle (highlighted in red)
+| Origin       = Thyroid and cricoid cartilages
+| Insertion    = Pharyngeal raphe
+| Blood        = Ascending pharyngeal artery
+| Nerve        = Pharyngeal plexus of the vagus nerve (CN X)
+| Action       = Constriction of the pharynx during swallowing
+}}
-The inferior pharyngeal constrictor muscle is an important muscle located in the pharynx, which is a part of the throat. It plays a crucial role in the process of swallowing and helps in the movement of food and liquids from the mouth to the esophagus. In this article, we will explore the anatomy, function, and clinical significance of the inferior pharyngeal constrictor muscle.
+The '''inferior pharyngeal constrictor muscle''' is one of the three [[pharyngeal constrictor muscles]] that form the muscular wall of the [[pharynx]]. It plays a crucial role in the process of [[swallowing]] by constricting the pharyngeal cavity and propelling the bolus of food from the [[oropharynx]] to the [[esophagus]].
-=== Anatomy ===
+==Anatomy==
+The inferior pharyngeal constrictor muscle is the thickest of the pharyngeal constrictors and is located in the lower part of the pharynx. It is composed of two parts:
-The inferior pharyngeal constrictor muscle is one of the three constrictor muscles of the pharynx, along with the middle and superior pharyngeal constrictor muscles. It is situated at the lower part of the pharynx, just above the esophagus. The muscle forms a circular band around the pharynx and is composed of two parts: the thyropharyngeal part and the cricopharyngeal part.
+* The '''thyropharyngeal part''', which originates from the oblique line of the [[thyroid cartilage]].
+* The '''cricopharyngeal part''', which originates from the lateral aspect of the [[cricoid cartilage]].
-The thyropharyngeal part originates from the oblique line of the thyroid cartilage, which is a part of the larynx. It inserts into the posterior median raphe, a fibrous structure in the midline of the pharynx. The cricopharyngeal part arises from the lateral aspect of the cricoid cartilage, another structure in the larynx. It also inserts into the posterior median raphe.
+Both parts insert into the [[pharyngeal raphe]], a fibrous seam that runs along the posterior midline of the pharynx.
-=== Function ===
+==Function==
+The primary function of the inferior pharyngeal constrictor muscle is to facilitate swallowing. During the act of swallowing, the muscle contracts sequentially with the other pharyngeal constrictors to constrict the pharyngeal cavity, pushing the food bolus downward into the esophagus. The cricopharyngeal part acts as a sphincter at the top of the esophagus, preventing air from entering the esophagus during breathing and preventing reflux of esophageal contents.
-The main function of the inferior pharyngeal constrictor muscle is to aid in the process of swallowing. During swallowing, the muscle contracts, causing the pharynx to constrict and propel the food or liquid towards the esophagus. This coordinated movement prevents the food or liquid from entering the airway and ensures that it reaches the stomach safely.
+==Innervation==
+The inferior pharyngeal constrictor muscle is innervated by the [[pharyngeal plexus]], which is primarily composed of fibers from the [[vagus nerve]] (cranial nerve X). The cricopharyngeal part also receives some innervation from the recurrent laryngeal nerve, a branch of the vagus nerve.
-Additionally, the inferior pharyngeal constrictor muscle also plays a role in the closure of the larynx during swallowing. It helps in the elevation of the larynx, which closes the opening of the trachea and prevents the entry of food or liquid into the respiratory system.
+==Blood Supply==
+The blood supply to the inferior pharyngeal constrictor muscle is primarily from the [[ascending pharyngeal artery]], a branch of the [[external carotid artery]].
-=== Clinical Significance ===
+==Clinical Significance==
+Dysfunction of the inferior pharyngeal constrictor muscle, particularly the cricopharyngeal part, can lead to swallowing disorders such as [[dysphagia]]. Cricopharyngeal achalasia, a condition where the cricopharyngeal muscle fails to relax properly, can cause difficulty in swallowing and may require medical or surgical intervention.
-Disorders or dysfunctions of the inferior pharyngeal constrictor muscle can lead to swallowing difficulties, also known as dysphagia. This can result in problems with eating, drinking, and even breathing. Dysphagia can be caused by various factors, such as neurological conditions, structural abnormalities, or muscle weakness.
+==Also see==
+* [[Pharyngeal constrictor muscles]]
+* [[Swallowing]]
+* [[Vagus nerve]]
+* [[Dysphagia]]
-In some cases, the inferior pharyngeal constrictor muscle may become hypertonic or spastic, leading to a condition called cricopharyngeal spasm. This can cause a sensation of a lump in the throat, difficulty swallowing, and sometimes pain. Treatment options for cricopharyngeal spasm may include medication, swallowing therapy, or in severe cases, surgical intervention.
+==Gallery==
+<gallery>
+File:Gray385.png|Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves.
+File:Gray957.png|Sagittal section of the pharynx, showing the pharyngeal constrictor muscles.
+File:Slide5iiii.JPG|Lateral view of the pharynx, highlighting the inferior pharyngeal constrictor muscle.
+</gallery>
-=== Conclusion ===
+{{Muscles of the head and neck}}
-The inferior pharyngeal constrictor muscle is a vital component of the pharynx and plays a crucial role in the process of swallowing. Its coordinated contraction helps propel food and liquids towards the esophagus while preventing their entry into the airway. Understanding the anatomy and function of this muscle is essential in diagnosing and managing swallowing disorders.<br>{{stub}}
+[[Category:Muscles of the head and neck]]
-{{dictionary-stub1}}
+[[Category:Pharynx]]