ANATOMY AND PHYSIOLOGY OF THE OESOPHAGUS.pptx

ANATOMY AND PHYSIOLOGY OF THE OESOPHAGUS

1. ANATOMY AND PHYSIOLOGY OF THE OESOPHAGUS

2. Oesophagus Muscular and tubular conduit extending from the caudal end of the pharynx( cricopharyngeus , C6 or level of the lower border of the cricoid cartilage) to the stomach(cardiac orifice or T11) Measures 25cm in adults with luminal diameter of 20-30mm Descends in the middle with deviation to the left by the effect of the thoracic arch of aorta and returns to the midline in the posterior mediastinum Anterior to the spine and posterior to the trachea in the neck with the recurrent laryngeal nerve in the tracheoesophageal groove

3. Has constriction caused/produced by Cricopharyngeal sphincter…………15cm from the incisor tooth Arch of Aorta ……….22cm Left main Bronchus… …….28cm Diaphragmatic hiatus… …37cm Cardiac sphincter ……40cm

4. Wall of the Oesophagus Mucous membrane layer Submucosa layer Muscular coat Outer Fibrous layer

5. MUCOUS MEMBRANE LAYER Stratified squamous cell epithelium continuous with that of the pharynx Lamina propria (loose connective tissue) has elastic fibres and GALT(gut associated lymphoid tissue) Muscularis mucosa

6. SUBMUCOSA LAYER Loosely connected to the mucous membrane Contains: >Blood vessel >lymphatics >Meissner’s plexuses of postganglionic parasympathetic nerve fibre >Minor mucus glands

7. MUSCULAR COAT LAYER Consist: Outer longitudinal muscle which is complete but diverge from the midline(laterally) at the upper end of the oesophagus , goes around anteriorly to insert to the posterior lamella of the cricoid cartilage Inner circular muscle which is continuous with the cricopharyngeus and continuous of the oblique fibres of the stomach Upper 3 rd striated muscle Middle 3 rd transition Lower 3 rd smooth muscle

8. OUTER FIBROUS LAYER External adventitia layer –dense connective tissue Phreno-oesophageal ligment is a condensation of this layer, attaches the oesophagus to the diaphragmatic opening

9. NERVE SUPPLY Recurrent laryngeal nerve to striated muscle Vagus nerve via parasympathetic to the smoothe muscle Cardiac Sympathetic trunk

10. BLOOD SUPPLY Inferior thyroid artery Left Subclavian artery Descending aorta Branches of bronchial artery Posterior intercostal artery Left gastric artery

11. PHYSIOLOGY Conduit for substances(food/fluid/gas): oesophageal phase of deglutition. Decompression of stomach Alaryngeal speech

12. CONCLUSION Knowledge of the anatomy of the oesophagus equips the physcian of The areas of narrowing where foreign bodies/food bolus(steak house syndrome) may lodge As a guide during instrumentation Pathologies that may arise from it