Esophagus and Pharynx Anatomy PDF

Applied Anatomy Series Dr. Rofayda Gaafar ,MD Lecturer of Radiodiagnosis  Learning Objectives By the end of lecture ,the student will be able to:  Recognize boundaries and parts of pharynx  Differentiate different parts of pharynx  Know different subsites of each part of pharynx ...

Applied Anatomy Series Dr. Rofayda Gaafar ,MD Lecturer of Radiodiagnosis  Learning Objectives By the end of lecture ,the student will be able to:  Recognize boundaries and parts of pharynx  Differentiate different parts of pharynx  Know different subsites of each part of pharynx  Identify upper GIT series on x ray  Know different parts of esophagus  Identify site of normal esophageal constrictors The digestive system Include: 1) The gastrointestinal tract (GIT): a hollow muscular tube starting from the oral cavity to the anus. 2) Various accessory organs: including the salivary glands, liver, pancreas and gall bladder PHARYNX & ESOPHAGUS GROSS ANATOMY The pharynx ❖ The pharynx is funnel-shaped with its It upper end being wider and located just below the lower surface of the skull (skull base), and its lower end is narrower and located at the level of cricoid cartilage (the sixth cervical vertebra (C6)) where the commencement of the esophagus posteriorly and the larynx anteriorly takes place ❖ Regionally, the pharynx divides into three parts which are from superior to inferior: - the nasal pharynx, located behind the posterior nasal apertures (choanae), the oral pharynx, located behind the opening of the oral cavity, and the laryngeal pharynx, located behind the inlet (opening) of the larynx The pharynx ❖ The nasopharynx: part of pharynx extends from the base of skull till the lower limit of the soft palate at C1/2 communicates anteriorly with the nasal cavity and inferiorly with the orophayrnx. ❖ The oropharynx: part of the pharynx extends from the lower part of the soft palate to the epiglottis/ continuous anteriorly with the oral cavity and inferiorly with the laryngopharynx. ❖ The laryngopharynx: part of the pharynx that lies behind the larynx/ extends from the level of the epiglottis to the level of C6, where it continues as the oesophagus.  The naso pharynx Anteriorly: posterior nares and posterior margin of nasal septum. Inferiorly: soft palate. Superiorly(roof): body of sphenoid and clivus Posteriorly: C1 and C2. Laterally o The pharyngeal opening of the Eustachian tube is located in the center of the lateral wall. o Lymphoid tissue aggregates, also known as the tubal tonsil occur around the opening of the Eustachian tube. o The fossa of Rosenmüller lies between the posterior margin of the Eustachian tube and the posterior wall of the nasopharynx. o Separated posterolaterally from the carotid sheath by styloid process and styloid muscle. The oro pharynx  The oro pharynx Contents The subsites of the oropharyngeal tissues include the following: Base (posterior third) of tongue (including lingual tonsils). Tonsillar complex (palatine tonsils, tonsillar fossae, and tonsillar pillars). Soft palate (inferior surface and uvula). Pharyngeal wall (lateral and posterior). Various spaces are included: Glossotonsillar sulci (area between base of tongue/lingual tonsils and palatine tonsils). Valleculae (space between the base of tongue and epiglottis) Oropharyngeal isthmus (space between the palatoglossal arches) The laryngopharynx ❖ The hypopharynx begins as the continuation of the oropharynx at the pharyngoepiglottic fold (which is at the level of the hyoid bone) superiorly, and extends inferiorly to the level of the inferior aspect of the cricoid cartilage (at the C6 vertebra level) where it continues as the cervical esophagus ❖ It contains three subsites Pyriform sinus. (Fig1.6). The pear-shaped subsite of the hypopharynx located posterolaterally to either side of the laryngeal opening. where the upper part of laryngopharynx wraps around the larynx, producing these two recesses. Postcricoid region. Posterior wall.  The esophagus ❖ It is a fibro-muscular tube, approximately 25cm in length, that transports food from the pharynx to the stomach ❖ It originates at the inferior border of the cricoid cartilage (C6) and extends to the cardiac orifice of the stomach (T11). ❖ In the neck, it descends behind the trachea and thyroid, lying in front of the lower cervical vertebrae. ❖ In the chest it passes behind the trachea, left main bronchus, aortic arch and left atrium. ❖ Then, It then passes behind the posterior sloping part of the diaphragm to enter the oesophageal hiatus in the diaphragm at the level of T10. ❖ It enters the stomach at the oesophagogastric junction.  The esophagus ❖ The esophagus is divided into three parts: 1) Cervical: continuous with the hypopharynx, begins at the lower border of cricoid cartilage (at level of C5/6) or cricopharyngeus muscle..till suprasternal notch 2) Thoracic: from suprasternal notch to the esophageal hiatus (T10) in the diaphragm. 3) Abdominal: from diaphragmatic esophageal hiatus and is continuous with the cardia of the stomach at the gastro-esophageal junction.  The esophagus  Upper Esophageal Sphincter The upper sphincter is an anatomical, striated muscle sphincter at the junction between the pharynx and esophagus. It is produced by the cricopharyngeus muscle. Normally, it is constricted to prevent the entrance of air into the esophagus.  Lower Esophageal Sphincter The lower esophageal sphincter is located at the gastro-esophageal junction (between the stomach and esophagus).  The gastro-esophageal junction is situated to the left of the T11 vertebra and is marked by the change from esophageal to gastric mucosa  The esophageal constrictors The anatomical relations of the esophagus give rise to four physiological constrictions in its lumen – it is these areas where food/foreign objects are most likely to become impacted. They can be remembered using the acronym ‘ABCD Arch of aorta Bronchus (left main stem) Cricoid cartilage (junction between esophagus and pharynx)  Diaphragmatic hiatus Radiological anatomy Plain film Lateral views of the skull and neck ❖ Plain radiograph has a limited role, with the lateral view mainly used to locate the presence of swallowed foreign bodies. ❖ The posterior wall of the pharynx forms a soft-tissue shadow curving posteroinferiorly below the body of the sphenoid and anterior to the cervical vertebrae. This shadow thins as it passes down anterior to the upper cervical vertebrae, measuring 3 mm anterior to C4 ❖ Below this the wall is thicker but should not exceed the AP diameter of the cervical vertebrae ❖ The base of the tongue and the epiglottis, forming the anterior surface of the oropharynx, are also identifiable on lateral radiographs The posterior and lateral walls of the nasopharynx may be identified on the basal skull projection and the piriform fossae of the laryngopharynx are seen on AP views of the neck Plain film Plain film Plain chest radiograph The esophagus is difficult to see unless it is dilated, and fluid filled. If the oesophagus contains air, the posterior aspect of the anterior oesophageal wall may be seen on the lateral film, behind the trachea This is known as the ‘posterior tracheal stripe.  Barium swallow ❖ It also known as a barium esophagogram or esophagram.It is a dedicated test of the pharynx, esophagus, and proximal stomach. It is a contrast-enhanced radiographic study commonly used to assess structural characteristics of the entire oesophagus and may be performed as a single or double contrast study. It may be used for the diagnosis of a wide range of pathologies including esophageal motility disorders, strictures, and perforations. It may also be used to characterize more distal pathology such as a hiatal hernia or gastric volvulus.  Barium swallow Contraindications Water-soluble contrast agents should be used instead of barium sulfate in the following cases: Suspected perforation. Postoperative assessment for leak. Tracheo-esophageal fistula Barium swallow ❖ On the frontal view: the oropharynx and hypopharynx may be examined. ❖ The valleculae and pyriform fossae are outlined by barium and the epiglottis and base of the tongue show as filling defects in the midline. Barium swallow ❖ On the lateral view the tongue base and epiglottis are seen from the side with the valleculae between. Barium swallow ❖A posterior indentation caused by the contraction of cricopharyngeus muscle to initiate deglutition indicates the beginning of the esophagus.  Barium swallow ❖ The cervical oesophagus lies on the ventral surface of the cervical spine ❖ The thoracic oesophagus is best demonstrated in the right anterior oblique position ❖ Barium swallow shows three impressions on the oesophagus – the aortic arch, left main bronchus and the left atrium ❖ Mild fusiform dilatation of the distal oesophagus forms the physiological sphincter. Barium swallow