Esophagus

• Esophagus


  25cm long fibromuscular tube that conveys food and liquids from pharynx to stomach
• Esophagus has 3 parts

  • Cervical part: 4cm long
  • Thoracic part: 20cm
  • Abdominal part: 1-5cm

  
• Extension of esophagus

  • Begins as continuation of pharynx at C6level
  • Pierces diaphragm at T10level to join stomach
  • Terminates at T11 levels

  
• Relations of cervical part of esophagus

  • Anterior: trachea; recurrent laryngeal nerves
  • Laterally: lobes of thyroid gland and common carotid
  • Posterior: longus coli, prevertebral fascia and cervical vertebra

  
• Relations of thoracic part of Esophagus

  • Anterior: trachea, arch of aorta, left principal bronchus, pericardium
  • Posterior: thoracic vertebra, right posterior intercostal arteries, azygous vein, thoracic duct, descending thoracic aorta at lower end.
  • Right sid: right mediastenal pleura, terminal part of azygous
  • Left side: left mediastinal pleura, left subclavian, thoracic duct

  
• Course of esophagus

  • Begins in neck at lower border of cricoid cartilage
  • in thorax, passes downward and to the left through the superior mediastinum (tracheas and arch of aorta anteriorly)
  • In posterior mediastinum (present anteriorly to thoracic aorta)
  • At sternal angle (T4) arch of aorta and left main bronchus pushes esophagus again to midline
  • In abdomen it descends for 1.3cm and joins stomach btw T10-11. Fibers from right crus of diagram form a sling around the Esophagus
  • At the opening of diagram its accompanied by: the two vagi, branches of left gastric vessels and lympahtic vessels.
• Esophagus relations


  Are

  
• Relations of abdominal Esophagus

  • Anterior: anterior vagal trunk (left vagus) + left lobe of liver
  • Posterior: post vagal trunk (right vagus) + left crus of diagram
• Arterial venous and lymphatic drainage of cervical part of esophagus

  • Arterial: inferior thyroid arteru
  • Veins: into inferior thyroid veins
  • Lymph: deep cervical nodes
• Arterial, venous and lymphatic drainage of thoracic esophagus

  • Arterial: descending thoracic aorta and bronchial arteries
  • Vein: azygous and hemiazygous
  • Lymph: sup and inf mediastenal nodes
• Arterial, venous and lymphatic drainage of abdomjnal esophagus

  • Arterial: left gastric artery+ lest inferior phrenic
  • vein: left gastric vein and inf hemiazygous veins
  • Lymph: celiac group of nodes
• Nerve supply to esophagus

  • Sympathetic: sympathetic trunk: from T5-T9
  • Parasympathetic: right + left vagus + left recurrent laryngeal

  At root of lungs the vagus nerve joins the sympathetic nerves to form esophageal plexus

  
• Motility of esophagus is controlled by autonomic nervous system with parasympathetic stimulation increasing peristaltic activity and sympathetic inhibiting it.
• Cervical Constrictions of esophagus

  • Cerical constriction: 15cm from incisor teeth. Caused by constriction of cricopharyngeal muscles. Function: prevents air from entering stomach during breathing
• Aortic constriction of esophagus

  • Cause by arch of aorta: occurs as esophagus passes behind arch of aorta into posterior mediastenum
  • 9inches from incisor
• Bronchoaortic constriction of esophagus

  • 11inches from incisor
  • when esophagus is crossed by aortic arch and left main bronchus
• Diaphragmatic constriction

  • Where Esophagus passed through oesophageal hiatus of diagram
  • Structure: lower oesophageal sphincter is a segment of circular muscles located at gastroesoohageal junction
  • Prevents reflux of gastric contents into esophagus
• • Oesophageal constrictions are common points where swallowed objects or food can become lodges causing obstruction
  • Pathological narrowing such as peptic strictures, malignancies occurs at or near these natural constriction.
• Constrictions of esophagus.

  1. 15cm from incisors teeth
  2. Aortic constriction: 23cm from incisors
  3. left main bronchus: 28cm from incisors
  4. diaphragmatic constriction: 40cm from incisors

  
• Esophagus is attached to esophageal hiatus via two ligaments known as phrenoesophageal ligaments.

  • these are made up of two limbs
  • asceding limb consists of supradiaphragmatic endothoracic fascia
  • descending limb: infradiaphragmatic transversalis fascia. Abdominal esophagus is an intraperitoneal organ: suspended by grastrophrenic lig.
• Esophagus blood supply

  • cervical esophagus: inferior thyroid a
  • thoracic esophagus: esophageal branches of thoracic aorta + bronchial arteries
  • abdominal esophagus: left gastric artery (celic trunk)

  
• Tunica mucosa of esophagus

  • mucosal infolding: esophagus is colapsed normally
  • stratified squamous non keratinized epithelium

  
• Submucosa of esophagus

  • submucosal glands: esophageal glands: exocrine glands, ompound tuboloexocrine glands. Secrete mucous. Lined with cuboidal epithelium.

  
• muscularis propria os esophagus

  • Upper 1/3: skeletal muscles
  • middle 1/3: skeletal and smooth muscles
  • lower 1/3. Smooth muscles only
  • myenteric (auerbach’s plexus): innervates these muscles.

  
• Adventia or serosa of esophagus

  
• Esophagus slide