OESOPHAGUS
OESOPHAGUS
- It is a narrow muscular tube measuring 25 cm long connecting pharynx with stomach.
- It begins as a continuation of laryngopharynx at the level of lower border of cricoid cartilage at the level of C6 vertebrae & passes through the diaphragm at the level of T10 through esophageal hitus of diaphragm.
- It ends at T11 level by opening into cardiac orifice of stomach.
- Oesophagus does not have straight course rather it presents anteroposterior curvatures.
- It is lined by stratified squamous non-keratinised epithelium.
- Esophagus is divided into three parts: 1) Cervical part (4 cm) 2) Thoracic part (20 cm) 3) Abdominal part (1-2 cm).
- Approximately 2 cm of the esophagus lie below the diaphragm in the abdomen (abdominal part of esophagus).
- Within this portion of esophagus the abdominal part of LES is located. Another 1-2 cm of LES lie above the diaphragm in mediastinum, i.e. thoracic part of LES.
- Thus total length of LES is 3-4 cm.
CONSTRICTIONS OF ESOPHAGUS
- Oesophagus shows 4 constrictions-
- At its begining at C6 vertebra:- 15 cm (6 inches) from incisor.
- At the level of T4 vertebra where it is crossed by arch of aorta:- 22.5 cm (9 inches) from incisor.
- At the level of T6 vertebra where it is crossed by left principal bronchus:- 27.5 cm (11 inches) from incisor.
- At the level of T10 vertebra, its pasage through esophagal hiatus of diaphragm (lower esophageal sphincter):- 37.5-40 cm (15-16 inches) from incisor.
- The narrowest part of the oesophagus is its commencement at the cricopharyngeal sphincter.
|
SITE |
VERTEBRAL LEVEL |
DISTANCE FROM CENTRAL INCISOR |
|
CRICOPHARYNX |
C6 |
15 |
|
AORTIC ARCH |
T4 |
25 |
|
LEFT MAIN BRONCHUS |
T6 |
28 |
|
OESOPHAGEAL HIATUS |
T10 |
40 |
BLOOD SUPPLY & LYMPHATIC DRAINAGE
- Arterial supply of cervical part is by inferior thyroid artery, thoracic part by azygous vein, & abdominal part by left gastric artery & left inferior phrenic artery.
- Venous drainage of cervical part is through inferior thyroid veins, thoracic part by azygous vein, & abdominal part by left gastric vein.
- Lymphatic drainage of cervical part is by deep cervical nodes, thoracic part is by posterior mediastinal nodes & abdominal part is by left gastric nodes.
Exam Important
- 3rd constriction of the oesophagus is at the level of Where it pierces the diapharm.
- Barrett’s oesophagus is Lower esophagus lined by columnar ephithelium.
- Ilnd constriction in oesophagus is seen at the Crossing of Aorta
- Oesophagus crosses the diaphragm at the level of T10.
- Arterial supply of cervical part is by inferior thyroid artery, thoracic part by azygous vein, & abdominal part by left gastric artery & left inferior phrenic artery.
Don’t Forget to Solve all the previous Year Question asked on OESOPHAGUS
Click Here to Start Quiz
Click Here to Start Quiz
