Overview of Micro & Macro Anatomy on Esophagus and Upper

GI tract

29 December 2016 (Thursday)

Association of Hong Kong Operating Room Nurses

Certificate Course in Upper Gastrointestinal Surgery & Perioperative Nursing

Where exactly is Upper GI Tract?

• Concentrate on the ESOPHAGUS and STOMACH today

Esophagus

• Around 25cm long

• Divided into 3 parts

• Cervical

• Thoracic

• Abdominal, 2cm in length

Esophagus

• Just anterior to the spine and posterior to the trachea

• Thoracic aorta crosses in front and to the left in the thorax

Esophagus

• Muscular tube

• Inner circular fibers

• Outer longitudinal fibers

Esophagus

• Muscular tube

• Inner circular fibers

• Outer longitudinal fibers

Esophagus

• Ends at the gastro-esophageal junction

• Landmark is the phreno-esophageal ligment

Arterial Supply

• Cervical part from inferior thyroid arteries

• Thoracic part directly from the aorta

• Abdominal part from the left gastric artery and inferior phrenic arteries

Venous Drainage

• Cervical part to inferior thyroid veins

• Thoracic part to azygous and hemiazygous vein

• Abdominal part to the coronary vein

Lymphatic Drainage

Nerve Supply

• Sympathetic and Para-sympathetic

• Sympathetic from Middle cervical ganglion and sympathetic chain

Nerve Supply

• Parasympathetic from the vagusnerve

Stomach

• Cardia

• Fundus

• Body

• Antrum

• pylorus

Stomach

Close relationship to:

• Pancreas

• Spleen

• Transverse colon

Stomach

Close relationship to:

• Pancreas

• Spleen

• Transverse colon

Arterial Supply

• Originate from the abdominal aorta celiac trunk

• Celiac trunk gives out 3 branches

Arterial Supply

• Left gastric artery

• Splenic artery

• Common hepatic artery

Arterial Supply

• Common hepatic arterygastroduodenalartery right gastroepiploicartery

Arterial Supply

• Splenic artery gives off the short gastric arteries + left gastroepiploicartery

Venous Drainage

• Same as the arterial supply

Venous Drainage

• Left gastric vein (coronary vein)

• Right gastric vein

• Left gastroepiploicvein

• Right gastroepiploicvein

• Short gastric veins

Lymphatic Drainage

Lymphatic Drainage

Nerve Supply

• Parasympathetic via the vagusnerve

• Anterior and posterior vagal trunks

Nerve Supply

• Sympathetic via the celiac ganglia and plexus

• Hepatic branch of the vagus nerve supplies the pylorus and the gallbladder

Nerve Supply

• Parasympathetic via the vagusnerve

• Anterior and posterior vagal trunks

• Sympathetic via the celiac ganglia and plexus

Nerve Supply

• Vagus nerve is a cord like structure on the surface of the esophagus

Histology of Esophagus

4 layers

• Mucosa

• Submucosa

• Muscularispropria

• Adventitia

Histology of Esophagus

Mucosa can be further divided into 4 layers

• Epithelium

• Basement membrane

• Lamina propria

• Muscularismucosa

Histology of Esophagus

• Epithelium is made of non-keratinized, stratified squamous epithelium

• protective function against the abrasive effects of food

Histology of Esophagus

• 2 layers of muscle

• Inner circular muscle

• Outer longitudinal muscle

Histology of Stomach

4 layers

• Mucosa

• Submucosa

• Muscularispropria

• Adventitia

Histology of Stomach

• Many different cells on the epithelium

• Parietal cells secrete hydrochloric acid + intrinsic factor

• Chief cells secrete pepsinogen + lipase (enzymes)

Histology of Stomach

• 3 layers of muscle

Histology of Stomach

• Oblique muscle

• Circular muscle

• Longitudinal muscle

Questions?