LObs Flashcards
Describe the peritoneum and its parts
The peritoneum is a continuous membrane which lines the abdominal cavity and covers the abdominal organs (abdominal viscera).
The parietal peritoneum lines the internal surface of the abdominopelvic wall.
It receives the same somatic nerve supply as the region of the abdominal wall that it lines; therefore, pain from the parietal peritoneum is well localised.
The Visceral peritoneum invaginates to cover the majority of the abdominal viscera.
Pain from the visceral peritoneum is poorly localised and the visceral peritoneum is only sensitive to stretch and chemical irritation.
Pain from the visceral peritoneum is referred to areas of skin (dermatomes) which are supplied by the same sensory ganglia and spinal cord segments as the nerve fibres innervating the viscera.
What is the peritoneal cavity?
The peritoneal cavity is a potential space between the parietal and visceral peritoneum. It normally contains only a small amount of lubricating fluid.
What is a Carcinoma?
Carcinoma is a type of cancer that starts in cells that make up the skin or the tissue lining organs, such as the liver or kidneys.
What does the ‘Adeno’ in Adenocarcinoma indicate?
That the carcinoma is derived from Glandular Mucosa
What is dysphagia?
Difficulty in swallowing
Draw the structure of the GI Tract histological layers:
- What is different in the layers of the oesophagus and lower part of the rectum?
They have adventitia instead of serosa, as they are located outside the peritoneal cavity
What is the structural difference between the oesophageal epithelium compared to that of the Small/Large intestine and stomach?
The oesophageal epithelium consists of squamous cells, as opposed to the columnar epithelium in the rest of the GI Tract
Cells with rounder shape and intercellular bridges are found toward the basal layer or surface of the squamous epithelium?
The basal layer, they flatter as they mature and rise toward the surface.
What is GORD?
Gastroesophageal reflux disease occurs when the amount of gastric juice that refluxes into the esophagus exceeds the normal limit.
Highly acidic (as low as pH 1) gastric contents damage unprotected squamous mucosa, leading to:
- Infiltration of the damaged surface epithelium by neutrophil polymorphs and eosinophils.
- Basal cell hyperplasia as epithelium proliferates to replace damaged cells
What is the main aetiological cause of GORD?
For more details, visit https://emedicine.medscape.com/article/176595-overview#a2
What are the four main complication of GORD?
Draw a diagram of a peptic ulcer and discuss its possible complications if present in the stomach or duodenum?
Give a definition of Barrett’s oesophagus:
What is metaplasia? And why does it occur secondary to GORD?
Metaplasia is the reversible replacement of the one mature type of epithelium by another in response to adverse circumstance. It is reversible if the stimulus is removed.
The mucus barrier of columnar epithelium protects against acid better than the squamous, hence the metaplasia.
What is dysplasia?
(Atypical NF can include nuclear enlargement, and pleomorphism - which is variation in shape and size of the nuclei)
How does carcinoma of the oesophagus present in patients?
What are the two types of adenocarcinoma in the oesophagus?
In what parts of the body/the world are squamous vs adeno carcinoma more common?
What are the principal features of the specialised gastric mucosa?
Parietal cells: Secrete gastric acid
Chief cells: Secrete pepsinogen which is activated by acid in the gastric lumen to form the active protease enzyme Pepsin.
What are the normal formed in the stomach, and what are some factors that might interfere with their function?
What are the two main irritants of the gastric mucosa that lead to gastritis?
H. Pylori and NSAIDs
Draw a diagram explaining how the stomach secretes acid: