Anatomy of the Esophagus || Course, Relations, Clinical Correlations скачать в хорошем качестве

Anatomy of the Esophagus || Course, Relations, Clinical Correlations

Anatomy of the Esophagus The esophagus, a vital component of the digestive system, is a fibromuscular tube approximately 25 cm (10 inches) long. It serves as the conduit for food and liquids from the pharynx to the stomach. Understanding its anatomy involves examining its course, relations, and clinical correlations. 📍 Anatomical Course The esophagus begins at the *inferior border of the cricoid cartilage* (C6 level) and extends to the *cardiac orifice of the stomach* (T11 level). It can be divided into three main segments: **Cervical Esophagus**: Extends from the lower pharynx to the thoracic inlet. **Thoracic Esophagus**: Passes through the mediastinum, lying posterior to the trachea and anterior to the spine. It is divided into upper, middle, and lower thoracic sections. *Abdominal Esophagus**: This segment is about 1.25 cm long, entering the abdominal cavity through the **esophageal hiatus* of the diaphragm at T10 and terminating at the stomach at T11[1][3][4]. 🔗 Anatomical Relations The esophagus is closely associated with several anatomical structures, which can lead to specific physiological constrictions where food may become impacted. These constrictions can be remembered using the acronym **ABCD**: **A**rch of the aorta **B**ronchus (left main stem) **C**ricoid cartilage **D**iaphragmatic hiatus The anatomical relations of the esophagus can be summarized in a table: Relation Anterior Posterior Right Left |-----------------|-------------------------------------|-----------------------------------|------------------------|--------------------------| Cervical Trachea Vertebral column N/A N/A Thoracic Heart, aorta Vertebral column Azygos vein Thoracic duct Abdominal Liver N/A N/A N/A ❤️‍🩹 Vascular Supply The esophagus receives its blood supply from different sources depending on its anatomical segment: *Thoracic Esophagus**: Supplied by branches of the **thoracic aorta* and the *inferior thyroid artery**. Venous drainage occurs via the **azygous veins* and **inferior thyroid vein**. *Abdominal Esophagus**: Supplied by the **left gastric artery* (from the celiac trunk) and the *left inferior phrenic artery**. Venous drainage is through the **left gastric vein* (to the portal circulation) and the *azygous vein* (to the systemic circulation), forming a **porto-systemic anastomosis**[1][3][5]. 🔬 Histological Structure The esophagus consists of several layers: **Mucosa**: Non-keratinized stratified squamous epithelium that transitions to columnar epithelium at the gastroesophageal junction. **Submucosa**: Contains esophageal glands that secrete mucus to facilitate food passage. **Muscularis Externa**: Composed of different muscle types: **Upper third**: Voluntary striated muscle **Middle third**: Mixed striated and smooth muscle **Lower third**: Smooth muscle **Adventitia**: The outer connective tissue layer, with a serosal covering only at the distal end[1][3][5]. 🏥 Clinical Correlations Several clinical conditions can affect the esophagus, including: **Gastroesophageal Reflux Disease (GERD)**: A chronic condition where stomach acid flows back into the esophagus, leading to symptoms like heartburn. **Dysphagia**: Difficulty swallowing, often due to esophageal strictures or muscular disorders. **Esophageal Cancer**: Can occur in any segment of the esophagus, with varying prevalence in the upper, middle, and lower thirds. **Esophageal Varices**: Resulting from portal hypertension, these are dilated veins in the esophagus that can rupture and cause significant bleeding. Understanding the anatomy and function of the esophagus is crucial for diagnosing and managing these conditions effectively[2][4][6]. Citations: [1] https://teachmeanatomy.info/abdomen/g... [2] https://my.clevelandclinic.org/health... [3] https://www.kenhub.com/en/library/ana... [4] https://training.seer.cancer.gov/ugi/... [5] https://www.ncbi.nlm.nih.gov/books/NB... [6] https://emedicine.medscape.com/articl... [7] https://radiopaedia.org/articles/oeso... [8] https://en.wikipedia.org/wiki/Esophagus [9] https://www.slideshare.net/slideshow/... Time Chapters 00:00 Intro 01:16 Course 03:38 Constrictions 05:44 Relations 12:16 Lower Esophageal Sphincter 13:26 Blood Supply 14:12 Venous Drainage 17:14 Lymphatic Drainage 17:43 Nerve Supply 19:29 Achalasia Cardia 21:30 Hiatal Hernia 22:25 Esophageal Carcinoma