1 F: The Esophagus & Deglutition (swallowing) Flashcards
Describe the gross anatomy of the esophagus
Flattened muscular tube of 18-26 cm from upper sphincter to lower sphincter.
What happens between swallows?
The esophagus is collapsed but the lumen can distend to approx. 2 cm in the anterior-posterior dimension & up to 3 cm laterally to accommodate a swallowed BOLUS
What does the esophagus connect?
Connects the pharynx to the stomach
Where does the Esophagus begin?
Begins at the neck at the Pharyngoesophageal junction (C5-6 interspace of the cricoid cartilage)
Where does the esophagus descend?
Descends anteriorly to the vertebral column through the superior and posterior mediastinum.
After traversing the diaphragm at the diaphragmatic hiatus (T10 vertebral level) where does it extend?
It extends thru the gastroesophageal junction to end at the orifice of the cardia of the stomach (T11 vertebral level)
Describe the histology of the esophagus
Non-keratinized stratified squamous
Why is the epithelial continuity critical for function?
A breach in the epithelium creates an ulcer
What does the Esophageal submucosa include? What does this help do?
Includes scattered esophageal glands.
**This provides mucus for lubricating the passage of food down the esophagus, augmenting that role of the salivary glands
What is the wall of the esophagus made up of?
1) The mucosa
2) Submucosa
3) Muscularis
Unlike the rest of the GI tract, the esophagus has what?
***Unlike the rest of the GI tract, the esophagus has NO TRUE SEROSAL OUTER LAYER, but is covered by a think & poorly defined layer of CT
In the esophagus, the submucosal vascular plexus includes what?
Especially large venous spaces (that drains away from the esophagus)
What does the Collateral of the L. Gastric Vein (a branch of the portal vein) receive venous drainage from?
From the mid and lower esophagus, plus from the submucosal venous plexus
Where are most of the veins in the esophagus found?
In the submucosal layer
What are Esophageal VARICES?
(“Varicose veins of the esophagus”)
-The submucosal venous spaces, along w/ all the other “draining” veins of the mid to lower esophagus may enlarge into esophageal varices.
In an Endoscopic image of perhaps a Cirrhotic patient w/ (portal hypertension), what is prominent?
Esophageal varices w/ red wale spots on the surface
***indicates a high risk of bleeding
In what case is Esophageal VARICES common?
Especially with portal hypertension (an increase in pressure in the portal vein, due to liver cirrhosis)
What is the risk with such varices?
They carry a substantial risk of rupture w/ fatal bleeding into the esophageal lumen
What does swallowing (deglutition) consist of ?
1) Oral or voluntary phase
2) Pharyngeal phase (involuntary)
3) Esophageal phase (involuntary)
What is swallowing initiated by?
Voluntary action of collecting the oral contents on the tongue & propelling them backward to the pharynx (oral phase)
What does the pharyngeal phase start with?
With a wave of involuntary contraction in the pharyngeal muscles that pushes the material into the esophagus, as the upper esophageal sphincter (UES) RELAXES and OPENS
What is part of the reflex response ?
Inhibition of respiration and stimulation of glottic closure
Why does the material tilt the epiglottis backward & down over the closed glottis ?
For further protection from food entering the respiratory airways
What phase is involved once food enters the esophagus, and peristalsis takes over
Esophageal phase
