Physiology and Pathology: The Esophagus Flashcards
Where esophagus passes through the diaphragm?
Esophageal hiatus
Esophageal Epithelium?
- Nonkeratinized stratified squamous epithelium
- Langerhans cells present
Esophageal Lamina Propria? (2)
- Esophageal cardiac glands (2 clusters) - secrete mucous
- Lymphoid nodules
Esophageal Muscularis Mucosa?
- Single layer of longitudinally smooth muscle
Esophageal Submucosa?
- Dense, irregular fibroelastic CT
- Mucous and serous cells
Esophageal Muscularis Externa?
- upper 1/3 mostly skeletal
- middle 1/3 mixed
- lower 1/3 mostly smooth muscle
When does the esophagus go from adventitia to serosa?
Once it passes through the esophageal hiatus (diaphragm)
Major arteries around esophagus? (2)
- Thoracic branches of aorta superiorly
- Branches of the left gastric artery inferiorly
Major venous drainage of esophagus?
- Azygous vein
- Left gastric vein
This interface is a pathologically important site of bleeding if the veins here rupture?
Where the portal circulation overlaps with systemic circulation
Esophageal branches => azygous vein
What muscles compress the esophagus superiorly?
Muscles that move the larynx and hyoid upwards and anteriorly
What are the major muscles for “pushing food down”?
- Cricopharyngeus muscle
- The rest of the inferior pharyngeal constrictor muscle
What can happed in the “weak spot” just above the cricopharyngeus muscle?
Zencker Diverticulum = outpouching develops that food gets stuck in
3 stages of swallowing?
- Voluntary stage
- Pharyngeal stage
- Esophageal stage
After the voluntary stage, swallowing becomes almost entirely _______
Automatic
What type of stimulation is food in the larynx?
Tactile stimulation
Why is it good that the soft palate is pulled upward in the pharyngeal stage of swallowing?
Blocks the nasal cavity
Swallowing center?
Medulla
What 2 nerves are mainly responsible for swallowing?
Vagus and Glossopharyngeal
What does the swallowing center temporarily inhibit?
Respiratory center = halts respiration at any point in the cycle
What results from distention of the esophagus by retained food, or by reflux of gastric contents into the esophagus?
Secondary peristalsis
How long does secondary peristalsis happen for?
Until all the food has emptied into the stomach
The lower esophageal sphincter normally remains _______ and _______
Tonic and constricted
Is the resting pressure of the upper esophageal sphincter high or low?
High
Is the resting pressure of the lower esophageal sphincter high or low?
Low
When is the pressure in the lower esophageal sphincter higher?
After food has passed into the stomach
What is relaxation of the lower esophageal sphincter mainly due to?
NO and VIP secreting branches of Vagus nerve
Basic groups of esophageal pathologies? (4)
- Dysphagic/Motility disease
- Inflammatory disease
- Metaplastic/neoplastic disease
- Vascular disease
Visceral pain from the esophagus is well-localized, and excess distention cause relatively intense, brief chest pain
Nutcracker esophagus
In nutcracker esophagus, outer longitudinal layer of smooth muscle ______ _______ inner circular layer
Contracts before
What do the high-amplitude esophageal contractions of nutcracker esophagus cause?
Short-lived esophageal obstruction
What is Diffuse Esophageal Spasm caused by?
Dysfunction in inhibitory nerves
Is diffuse esophageal spasm common?
Yes
What is characterized by incomplete LES relaxation, increased LES tone, and aperistalsis of the esophagus?
Achalasia
Primary achalasia?
- Idiopathic
- Caused by failure of distal esophageal inhibitory neurons
If inhibitory neurons do not release NO or VIP after swallowing, what happens?
The lower esophageal sphincter won’t relax
Secondary achalasia? (2)
- Diabetic autonomic neuropathy
- Malignancy
What can the tropical infection Trypanosoma cruzi cause?
Secondary achalasia
Clinical features of Achalasia? (3)
- Dyspepsia
- Chest pain
- Regurgitation
Treatment for Achalasia?
- Botox
- Myotomy
What can iron-deficiency anemia or chronic reflux disease sometimes cause?
Fibrosis or non-malignant growths that obstruct the esophagus
What can cause Infectious Esophagitis? (3)
- HSV (small “punched-out” lesions)
- Cytomegalovirus (CMV)
- Fungal organisms
Autoimmune esophagitis causes? (3)
- Crohn’s (rare)
- Scleroderma
- Eosinophilic esophagitis
What are the more common findings of scleroderma?
Mostly obstructive and regurgitation (vs inflammatory findings)
Population that Eosiniphilic esophagitis typically affects?
Children and Adults
Esophagitis that is usually distributed throughout the length of the esophagus, with primarily esosinophilic inflammation
Eosinophilic Esophagitis
Eosinophilic esophagitis has marked _____ cell hyperplasia and ________ of the submucosal papillae
Basal; Elongation
In eosinophilic esophagitis, Th2 cells are responsible for an abundance of what in the serum of effected tissue?
IL-4, IL-5, IL-13
Patients often have a Hx of what before GI Sx of Eosinophilic eso.?
Atopic illness
Clinical features for children with eosinophilic eso.? (3)
- Nausea and vomiting
- Small for age
- Weight loss if severe
Clinical features for adults with eosinophilic eso.? (3)
- Dysphagia
- Food impaction
- Chest pain
Diagnosis of eosinophilic eso.? (2)
- Endoscopy
- IgE levels often elevated
What is the most common cause of esophagitis?
Reflux of gastric contents into lower esophagus
Decreased LES tone or increased abdominal pressure likely contribute to ______
GERD
Common findings of Reflux Esophagitis? (4)
- Hyperemia
- Mild eosinophilic infiltration
- Basal zone hyperplasia
- Barrett’s Esophagus
Patches of red, velvety mucosa extending upward from the gastroesophageal junction that alternate with the smooth, pale normal esophageal mucosa
Barrett’s esophagus
In Barrett’s Esophagus, metaplasia looks similar to _______ ________ _______– goblet cells are present – with time many will progress to dysplasia
Intestinal glandular epithelium
Clinical features of Reflux esophagitis? (3)
- Dysphagia
- Heartburn
- Regurgitation (sometimes)
Treatment for Reflux esophagitis?
PPIs or H2 Histamine receptor antagonists
