MECHANISMS OF CARDIAC ARRHYTHMIAS. DR AMNA TAHIR PHYSIOLOGY DEPARTMENT. KEMU.
HISTOLOGY OF ESOPHAGUS & GASTRO ESOPHAGEAL JUNCTION By Dr. Sobia Ibrahim Assistant Professor...
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Transcript of HISTOLOGY OF ESOPHAGUS & GASTRO ESOPHAGEAL JUNCTION By Dr. Sobia Ibrahim Assistant Professor...
HISTOLOGY OF ESOPHAGUS &GASTRO ESOPHAGEAL JUNCTION
By Dr. Sobia Ibrahim
Assistant Professor Anatomy,
KEMU
ESOPHAGUS
Is muscular tube
Extends from pharynx
to stomach
Wall has four layers:
Mucosa
Epithelium
Lamina propria
Muscularis interna or
muscularis mucosae
Submucosa
Muscularis externa
Adventitia / Serosa
UPPER 1/3 OF ESOPHAGUS MUCOSA
Epithelium: Stratified squamous non-keratinized
Lamina propria: scattered lymphocytes, few lymphatic nodules, mucous glands, blood vessels
Muscularis mucosae: Thick, smooth muscles
longitudinally arranged
SUB-MUCOSA Collagen & elastic fibres,
mucous glands, blood vessels, nerves
MUSCULARIS EXTERNA Skeletal (striated) muscles
ADVENTITIA Collagen & elastic fibers,
blood vessels
MIDDLE 1/3 OF ESOPHAGUS MUCOSA Epithelium: stratified squamos non-
keratinized Lamina propria: : scattered lymphocytes,
few lymphatic nodules, mucous glands, blood vessels
Muscularis mucosae: thick, smooth muscles longitudinally
arranged
SUB-MUCOSA Collagen & elastic fibres, mucous glands,
blood vessels, nerves
MUSCULARIS EXTERNA Skeletal (striated) muscles, Smooth muscles
ADVENTITIA Collagen & elastic fibers, blood &
lymphatic vessels
LOWER 1/3 OF ESOPHAGUS
MUCOSA Epithelium: Simple columnar
Lamina propria: scattered lymphocytes, few lymphatic nodules, mucous glands, blood vessels
Muscularis mucosae: thick, smooth muscles
longitudinally arranged
SUB-MUCOSA Collagen & elastic fibres, mucous
glands, blood vessels, nerves
MUSCULARIS EXTERNA Smooth muscles
ADVENTITIA/ SEROSA Collagen & elastic fibers, blood &
lymphatic vessels
GASTROESOPHAGEAL REFLUX DISEASE
It is associated with incompetent barriers at this junction; caused by hiatal hernia, decrease in lower esophageal sphincter tone.
Results in reflux esophagitis as mucosal barriers are not sufficient to protect esophagus from acids, pepsin & bile
causing heart burns/atypical chest pain
BARRETT’S ESOPHAGUS
Reflux of gastric contents throu lower esophageal sphincter Gastric acid in esophagus Heart burn With time, metaplasia of epithelium (protective) Barrett’s esophagus High risk for carcinoma
STOMACH
PARTS OF STOMACH
Cardia
Fundus
Body
Pylorus
Rugae
Three histological zones
CARDIOESOPHAGEAL JUNCTION
Esophageal cardiac junction
MUCOSA:1:Epithelium changes from: Startified squamous non keratinised into simple columnar.2: Lamina propria: esophageal cardiac glands but in stomach (cardiac, fundic and pyloric glands).They are tubular and deep.3:Muscularis mucosae: thick longitudinal in esophagus but thin and two layered in stomach.Submucosa: esophageal glands proper disappear. No glands in submucosa of stomach.Muscularis externa: three layered in stomach an additional oblique layer is there
GASTROESOPHAGEAL REFLUX DISEASE
• It is associated with incompetent barriers at this junction; caused by hiatal hernia, decrease in lower esophageal sphincter tone.
• Results in reflux esophagitis as mucosal barriers are not sufficient to protect esophagus from acids, pepsin & bile
• causing heart burns/atypical chest pain