Esophageal Diseases

5 Esophageal Diseases



Anatomy of the Esophagus



image

Esophagus in Situ


• Fibromuscular tube (~25 cm) running from the pharynx in the neck, through the thorax and diaphragm, to the stomach in the abdomen

• Runs just posterior to the trachea and anterior to vertebral bodies in the neck and superior mediastinum

• Runs just posterior to the heart (left atrium and left ventricle) in the posterior mediastinum

• Tends to run to the left below T4 but is pushed to the center by the arch of the aorta and the root of the left lung

• Esophageal hiatus of the diaphragm is to the left of midline, at the level of the T10 vertebra.

• Upper esophageal sphincter: circular muscle of the superior esophagus, including the cricopharyngeus, the first region of anatomical constriction

• Also compressed in its course by 3 structures, as seen on barium swallow (when expanded)
image Arch of the aorta

image Left main bronchus

image Diaphragm: passes between the superior fibers of the right crus

• Ends at the cardial orifice of the stomach, left of midline

• Retropharyngeal danger space: possibility of infection spreading retroesophageally into the thorax


Microscopic Anatomy



Mucosa



• Highly folded stratified squamous epithelium, with walls in apposition unless distended by swallowing

• Mucous glands more numerous inferiorly


Tunica Muscularis



• Inner circular: continuous superiorly with the circumferential fibers of the inferior pharyngeal constrictor

• Outer longitudinal
image Upper third is striated (voluntary muscle) like the pharynx.

image Middle third is a combination of striated and smooth muscle.

image Lowest third is smooth muscle.


Tunica Adventitia



• Fibrous, not serous

• Has embedded arterial, venous, and nerve plexuses

image

Nerves of Esophagus



Innervation



• The esophageal nerve plexus is composed of vagal afferent and efferent, sympathetic efferent, and segmental sensory components.

• Parasympathetic preganglionic fibers
image Upper (cervical) portion from the recurrent laryngeal nerve

image Thoracic portion from the vagus via the pulmonary plexus (peribronchial)

image Ganglion cells located in myenteric plexuses

• Sympathetic postganglionic fibers
image Via nerves from cervical and thoracic chains

image From cervical ganglia and thoracic ganglia

• Sensory fibers (visceral afferent)
image Vagus: stretch, chemoreceptor, nociceptor; to vagal ganglia

image Segmental (parallel to sympathetics) with spinal nerves; to cervical and thoracic dorsal root ganglia


Vessels and Lymphatics



• Extensive submucosal vascular plexuses allow mobilization of large extents of the esophagus with reduced risk of ischemia.

image

Arteries of Esophagus



Arterial Supply



• Cervical portion is supplied by branches of the inferior thyroid arteries from thyrocervical trunks of the right and left subclavian arteries.

• Thoracic branches (unpaired) from the adjacent aorta

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Aug 12, 2016 | Posted by in ANATOMY | Comments Off on Esophageal Diseases

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