Pharynx and Esophagus PDF

Digestive system Pharynx and Esophagus  Pharynx (throat Latin) Out lines  Location of the pharynx  Boundaries  Wall of the pharynx  Parts  Pharynx bothdigestionand hasafunctionin respiration Is funnel shaped...

Digestive system Pharynx and Esophagus  Pharynx (throat Latin) Out lines  Location of the pharynx  Boundaries  Wall of the pharynx  Parts  Pharynx bothdigestionand hasafunctionin respiration Is funnel shaped muscular tube 13 cm cricoidcartilage Extends from base of skull to the lower border of C6 tothe posterior Is located behind the nasal and oral cavity Its three parts  Nasopharynx  Oropharynx  laryngopharynx Boundaries of the pharynx sphenoid orepiglottis epiglottis orhyoidbone or co  thestructureofthepharynxareprotectedbyawallcalledpharyngealwall ithas4layer posteriorly coverthe that fibroussheath membrane mucous separates mucilefrom apneurosis partofpharynx thickest mostsuperficiallayer  Pharyngeal Wall Pharyngeal Raphe: Connective tissue descends from the pharyngeal tubercle on the to sun the on tubercle superiorlyattached pharyngeal base of the skull to the level C6 the with continuous inferiorly oceanaga adventitia forinsertionof itisimportant the muscle  Constrictor muscles ACTION : Swallowing NERVE SUPPLY: pharyngeal plexus by formed division.eu ago bone hyoid a EE Eanene  t.fitierior In muscle that tube osteocartilaginous extend to ear p harynxmiddle from and inferior Efomiddle muscle tothe inferior constrictor inferior  Longitudinal muscles at is I named Inachement Elevate the pharynx Pharyngobasilar fascia Salpingopharyngeus muscle e pharyngeal plexus Palatopharyngeus muscle Himm palatine Stylopharyngeus pharyngeal plexus muscle a It close oropharyngeal Glossopharyngeal N isthmu All the muscles of pharynx ( longitudinal and constrictor) are innervated by pharyngeal plexus except stylopharyngeus muscle which is supplied by glossopharyngeal nerve. Q/ which of the following is not supplied by pharyngeal plexus? Stylopharyngeus muscle  asitscoveredby therespiratoryepithelium anteriorly pnamngeact.mil baseof theskull MIT 0 beenlargedbybacterialorviral imay fine withtheopeningoforopharynxthroughaspacealledpharyngeal 1itandcervicalvertebraandiscovered byfascia The Center of the lateral wall of the nasopharynx has the Eustachian tube AKA auditory tube , its function is pressure balance the tube itisamucous Torutubarias just above eustachian that brane the covers part distal oeevitacnia.ie i iii iii Nasopharynx AKAadenoid Pharyngeal tonsil I forinfection na.mx Torus tubarius I Pharyngeal recess Salpingopharyngeal fold nasopharyngeal isthmus  AKApharyngeal Enlarged Adenoid Tonsils inroof The adenoid tonsils can become pathologically enlarged due to viral infections of the upper respiratory tract.. When enlarged, the adenoids can obstruct the opening of the Eustachian tube – which is located close to the adenoid tonsils in the nasopharynx. This can lead to chronic otitis media Q/ why does the in ammation of the nasopharynx pharyngeal tonsil cause otitis media? Because the pharyngeal tonsils are located near the opening of Eustachian tube in the lateral wall so once infected they obstruct the Eustachian tube causing otitis media mainfunction function accessory anterior213rdisoral cavity 5 Ed eiEiiiiiiparatine anterio.tn stonguerosteviarfoldextendifom has palatine auegneonlymus.iecovered mucous membrane between theeocanthereiparatinefouaorthepaatineton.in lateral 9 Vallecule letb c and c aeea t ianderinotii  superiorly extends from epiglottis Inferiorly ends at level of c6 or cricoid cartilage ( continuous with esophagus ) Puredigestivefunction Damage to the internal laryngeal nerve found within the piriform fossa may cause paralysis of upper respiratory tract because it supplies the muscles of pharynx and larynx Site of accumulation of foreign body Beneath the mucosa is a internal laryngeal N. removal of foreign body from the fossa may damage the nerve and lead to anesthesia in the pharynx and larynx  Pharyngeal Diverticulum (Pouch) The inferior pharyngeal constrictor is split into two parts; the thyropharyngeus and the cricopharyngeus. Inferior part of the larynx is the weakest part which is the inferior constrictor muscle This area between two muscles is a weak area in the mucosa. It is possible for food to accumulate here called diverticulum and Q/ the inferior part of the pharynx is a common site for diverticulum why? Because it’s the weakest part. leading to dysphagia Q/ Why is it the weakest part? Because the inferior constrictor muscle is made up of 2 parts that are separated from each other by a gap or space, this space is not covered by muscle it is only covered by mucous membrane Sensory Nerve Supply of the Pharyngeal Mucous Membrane Nasal pharynx: The maxillary nerve (V2) Oral pharynx: The glossopharyngeal nerve Laryngeal pharynx The internal laryngeal branch of the vagus nerve Blood Supply of the Pharynx Ascending pharyngeal, tonsillar branches of facial arteries, and branches of maxillary and lingual arteries Lymph Drainage of the Pharynx Directly into the deep cervical lymph nodes or indirectly via the retropharyngeal or paratracheal nodes into the deep cervical nodes node Directly Deep cervical nodes tracheal Indirectly retropharyngeal para DeepcervicalNodes  Esophagus related apt.fiitfotIeitaivertebrae 25 cm long muscular tube continues from lower end of pharynx at the lower border of cricoid cartilage opposite the body of 6th cervical vertebra. extendfromcoTn butpiercesthediaphragmat to Is dividedinto3 parts Descends in the neck (cervical 1 part), superior and posterior part a mediastinum (thoracic part), longest pierces the right crus of diaphragm at the level of 10th thoracic vertebra to enter the abdomen and joins the cardiac end of stomach C6 Abdominalpart isachart.inaitdatestht Emdneesssconinater  Cervical part lessthan7am Vagus nerve Blood Supply of the by inferior thyroid artery & vein. Nerve supply recurrent laryngeal nerves & thyroid gland branches of middle cervical sympathetic ganglion Inferior thyroid Relations of Cervical Part artery Posteriorly: the 6th & 7th cervical vertebrae and prevertebral muscles & fascia. Anteriorly: the trachea & recurrent recurrent laryngeal nerve laryngeal nerve Laterally: the thyroid gland, carotid sheath and its contents, and the thoracic inferior thyroid artery & vein. duct on the left. Common carotid artery Internal jugular vein anteriorrelationofesophagusistrachea betweentrachea andesophaguslietherecurrentlaryngealnerve thoracicpartesophagealbranchofdescending s upplyof Blood aorta posteriorrelation I  Thoracic part and of esophagus cava superiorvena deoxygenatedblooddirectly goes toInferior part of the venous blood from the esophagus enters the systemic circulation (via the azygos system) and part enters the portal circulation (via the left gastric vein). Esophageal branches descending of thoracic aorta Azygos vein venous.hn Left gastric vein edtfrculatio venoyiatitcuation Esophageal branch of left gastric artery  Posterior view Vagus nerve Posterior view Left recurrent laryngeal nerve Branches to esophageal plexus from sympathetic Esophageal plexus trunk, greater splanchnic (anterior portion) nerve, and thoracic ismainlyformedbyvagalnerve Esophagealplexus aortic plexus Posterior Anterior vagal trunk vagal trunk  byleftgastricarch whichisapartofceliacartery supplied blood Deoxygenated nutrient gotoliverbyportalvein  narrowing Oesophageal constrictions They can be remembered using the acronym ‘ABCD‘ c Cricopharyngeal constriction (at the beginning) 15 cm from the incisors, at the level of the cricoid cartilage (C6), which is the narrowest part of the esophagus. This is where the esophagus begins after passing through the upper esophageal sphincter the where incontinuous pharynx with elophago for it m the after onehageal which sphincter by crossed crico muscle pharyngeal Aortic arch constriction A Located 23 cm from the incisors, where the esophagus is crossed by the arch of the aorta at the level of T4. Left main bronchus constriction B 25 cm from the incisors, where the esophagus is crossed by the left main bronchus. This is at the level of the intervertebral disc between T4 and T5. bronchi by formed left main principle Diaphragmatic constriction 40 cm from the incisors, where the esophagus passes through the esophageal hiatus of the diaphragm at the level of T10. the the w hen esophaguspierces diaphragm formed  Oesophageal Sphincters Theyrephysiologicalsphincter formed smooth by muide There are two sphincters present in the oesophagus, known as the upper and lower oesophageal sphincters. They act to prevent the entry of air and the reflux of gastric contents respectively. Upper Oesophageal Sphincter atlevelofco located The upper sphincter is an anatomical, striated muscle sphincter at the junction between the pharynx and oesophagus. It is produced by the cricopharyngeus muscle. Normally, it is constricted to prevent the entrance of air into the oesophagus.  Lower Oesophageal Sphincter its Entitin muscle madeupofsmooth The lower oesophageal sphincter is located at the gastro-oesophageal junction (between the stomach and oesophagus). The gastro-oesophageal junction is situated to the left of the T11 vertebra, and is marked by the change from oesophageal to gastric mucosa. The sphincter is classified as a physiological (or functional) sphincter, as it does not have any specific sphincteric muscle. Instead, the sphincter is maintained by four factors: it isformedbythepressureof4factor Oesophagus enters the stomach at an acute angle. Walls of the intra-abdominal section of the oesophagus int iii n are compressed when there is a positive intra-abdominal pressure. Prominent mucosal folds at the gastro-oesophageal junction aid in occluding the lumen. Theoryfaithftp.baraneandsmoothmuscleof itself prevents esophagus Right crus of the diaphragm has a “pinch-cock” effect. During oesophageal peristalsis, the sphincter is relaxed to allow food to enter the stomach. Otherwise at rest, the function of this sphincter is to prevent the reflux of acidic gastric contents into the oesophagus. nYIffisntindityforlandaetinagia The.lamnin Pyrosis Ispiag.ie Yi.ttrefcked faiciathingtahie The abdominal oesophagus drains into both the systemic and portal circulation, forming an anastomosis between the two. is and of engorgement enlargement around veins e sophagus Oesophageal varices are abnormally dilated sub-mucosal veins (in the wall of the oesophagus) that lie within this anastomosis. an obstruction in the portal vein lead to (vomiting of blood). sit tie in The abdominal oesophagus drains into both the systemic and portal circulation, forming an anastomosis between the two. Oesophageal varices are abnormally dilated sub-mucosal veins (in the wall of the oesophagus) that lie within this anastomosis. These varices represent an engorgement and enlargement of veins around the oesophagus. An obstruction in the portal vein, often due to cirrhosis or cancer of the liver or pancreas, leads to increased venous pressure, causing blood to reroute through the systemic circulation. This pressure increase can result in the rupture of the varices, causing hematemesis (vomiting of blood).