1. DEMO – II Esophagus Ali Jasim Alhashli Year III – Unit V (GI & Renal Systems)

2. STATION – 1 (Peritoneum & Peritoneal cavity) The peritoneum has two layers: The peritoneum has two layers: -An outer parietal layer: sensitive to touch, hot, cold, pain (localized). In its central portion it is innervated by the phrenic nerve (originating from C3, C4, C5). It its lateral portions, it is innervated by the lower T6 thoracic nerve. -An inner visceral layer: which is insensitive and innervated by the autonomic nervous system. Note: there is a space between the two layers filled with serous peritoneal fluid which prevents friction of organs.

3. The peritoneum has two folds: The peritoneum has two folds: -Omental fold: which extends from the greater curvature of the stomach to the colon (greater omentum). It is composed of fat, vessels, lymphatics and nerves. Note: 3 ligaments are found within the greater omentum: *Gastro-phrenic ligament. *Gastro-splenic ligament. *Gastro-colic ligament. -Lesser omentum: extending from the lesser curvature of the stomach to the liver Note: 2 ligament are found within the lesser omentum: *Hepato-gastric ligament. *Hepato-duodenal ligament. Gastro-colic ligament Gastro-splenic ligament Hepato-duodenal ligament Hepato-gastric ligament STATION – 1 (Peritoneum & Peritoneal cavity)

4. The peritoneum has 2 sacs: The peritoneum has 2 sacs: -The greater sac: which is connected to: -The lesser sac (omental bursa) by the epiploic (omental) foramen. Note: the lesser sac in posterior to the stomach. Paracolic gutters: these are empty spaces which will be filled with fluid in case of peritonitis. Therefore, peritoneal cavity will be reduced resulting in more friction between organs. Mesocolon --- < large intestines. Mesentery --- < small intestines. Intraperitoneal organs: stomach, spleen Retroperitoneal organs: kidneys, suprarenal glands, pancreas & part of the duodenum. Note:infemales,infectionofthe peritoneum is more common because it is connected to the exterior of the body. 1.The lesser omentum 2.Transverse mesocolon 3.Small bowel mesentery 4.Sigmoid mesentery STATION – 1 (Peritoneum & Peritoneal cavity)

6. STATION – 2 (Esophagus Anatomy) It starts from C6/ lower border of It starts from C6/ lower border of the cricoid cartilage. level of T10. It passes through the diaphragm (esophageal hitus) at the level of T10. is 25 The length of the esophagus is 25cm. It has 2 sphincters: It has 2 sphincters: - The upper esophageal sphincter (UES):formedbythe cricopharyngeal muscle. - The lower esophageal sphincter (LES): it is a physiologic sphincter. The esophagus has 4 constrictions The esophagus has 4 constrictions (see the picture).

7. Cervical esophagus: Cervical esophagus: -Anterior: trachea. Between the esophagus & trachea is recurrent laryngeal nerve. -Posterior: cervical vertebrae. -Lateral: lobes of the thyroid gland. Thoracic esophagus: Thoracic esophagus: -Arch of the aorta. -Left main bronchus. -Left atrium of the heart. Abdominal esophagus: Abdominal esophagus: - Very short part (1.5cm). Note: cervical part of the esophagus is innervated by the recurrent laryngeal nerve. Middle & lower parts are innervated by esophageal plexus of nerves (vagus) and greater splanchnic nerve (sympathetic). STATION – 2 (Esophagus Anatomy)

8. : fibro-optic endoscopy. Diagnosis of pathologic conditions in the esophagus is done using: fibro-optic endoscopy. Barium swallow: Barium swallow: is also done using barium sulfate (contrasting medium). Picture: bird-beak showed with barium swallow in case of achalasia (failing to relax LES + loss of motility). GERD (Gasto-Esophageal Reflux Disease) might cause Barret esophagus which is a risk factor for esophageal adenocarcinoma. GERD (Gasto-Esophageal Reflux Disease) might cause Barret esophagus which is a risk factor for esophageal adenocarcinoma. Note: squamous cell carcinoma is more common worldwide. Gastroesophageal region. Barrett's esophagus, demonstrating proximal extension of columnar-lined mucosa well into the tubular esophagus. This columnar- lined mucosa extends more than 2 cm from the proximal gastric folds ( arrows ). STATION – 2 (Esophagus Anatomy)

9. STATION – 3 (Histology of The Esophagus)

15. The pharynx is a 12 cm muscular tube extending from the cranial base to the inferior border of the cricoid cartilage anteriorly and the inferior border of C6 vertebra posteriorly. STATION – 4 (Pharynx) Interior of The Pharynx Nasopharynx Relations: -Anterior: choanae -Posteior: occipital bone & 1 st cervical vertebra. -Superior: occipital bone & sphenoid bone. -Inferior: soft palate. -Lateral: tubal fold, tubal fossa with tubal tonsils & the opening of the auditory tube. Note: The pharyngeal tonsils (commonly called adenoids when enlarged) are in the mucous membrane of the roof and posterior wall of nasopharynx. Oropharynx Relations: -Posterior: 2 nd & 3 rd cervical vertebrae. -Superior: soft palate. -Inferior: base of the tongue. -:Lateral palatoglossal & palatopharyngeal arches. -Note: the palatine tonsils are collections of lymphoid tissue on each side of the oropharynx that lie in the tonsillar sinus. The sinus is between the palatoglossal and the palatopharyngeal arches. Laryngopharynx -It lies posterior to the larynx, extending from the superior border of epiglottis to the inferior border of cricoid cartilage (C4-C6 vertebrae). -Note: the piriform fossa is a small depression of the laryngopharyngeal cavity on each side of the inlet.

16. STATION – 4 (Pharynx)

17. Superior constrictor muscle Hyoid bone Thyro-hyoid membrane Thyroid cartilage Cricoid cartilage Trachea Styloid process Stylo-hyoid ligament Middle constrictor muscle Inferior constrictor muscle STATION – 4 (Pharynx)

18. The overlapping of the constrictor muscles leaves four gaps in the musculature for structures to enter or leave the pharynx Superior to the superior constrictor 1Levator veli palatini 2Pharyngotympanic tube. 3- Ascending palatine artery. A gap between the superior and the middle pharyngeal constrictors 1Stylopharyngeus. 2Glossopharyngeal nerve. 3Stylohyoid ligament. A gap between the middle and the inferior pharyngeal constrictors 1Internal laryngeal nerve. 2Superior laryngeal artery and vein. A gap inferior to the inferior pharyngeal constrictor 1- Recurrent laryngeal nerve. 2- Inferior laryngeal artery. STATION – 4 (Pharynx)

19. STATION – 5 (Same as what was mentioned in previous stations) Good Luck!