Abdomen/GIT Flashcards
What muscle is the most superficial muscular layer and in which direction do its fibres fun?
External oblique and its fibres run inferiorly from lateral to medial
All the muscular layers of the abdominal wall form apopneuroses across the medial part of the abdominal anterior wall - what do they form?
The linea alba (white line)
What muscle lies beneath external oblique and in what direction do its fibres run?
Internal oblique and at 90 degrees to external oblique fibres
What is the deepest muscular layer in the abdomen? What direction does its fibres run?
Transverse abdominus - fibres run transversely
What muscle forms the “six pack”? What is it enveloped by?
Rectus abdominus rectus sheath (the apopneuroses)
What blood vessel supplies the inferior abdominal wall?
Inferior epigastric artery, deep circumflex iliac arteries - branches of the external iliac artery
What blood vessel supplies the superior abdominal wall?
Superior epigastric artery
What is the venous drainage of the inferior part of the abdominal wall?
3 inguinal veins (superficial) drain into the greater saphenous vein
What is the venous drainage of the superior part of the abdominal wall?
Superficial epigastric vein
What is peritoneum?
Thin single celled layer of mesothelium
What is parietal peritoneum?
The mesothelium that covers the internal surfaces of the abdominal wall
What is visceral peritoneum?
The mesothelium that envelops the abdominal viscera
What is mesentery?
A double layered flap of peritoneum connects viscera to abdominal wall - contains blood vessels, nerves and lymphatics and fat stores
What is an omentum and what are the two omentums?
Double layered peritoneum that connects stomach to other organs: greater and lesser
Where does the greater omentum run?
Starts from greater curvature of the stomach and proximal part of duodenum –> hangs like an apron and passes back up to the transverse colon
Where does the lesser omentum run?
Between the liver and the lesser curve of the stomach
What does the inguinal canal connect and why is it clinically significant?
Connects the abdomen to the scrotum and is significant as it is a weak spot prone to herniation
What are the four main layers of the GIT moving from the lumen outwards?
Mucosa, sub-mucosa, Muscularis and Serosa
Briefly describe the mucosal layer of the GIT
Epithelial layer, underneath which is a connective tissue layer called the lamina propria - contains GALT, the innermost layer is the muscularis mucosa and is the innermost layer of smooth muscle.
Describe the submucosa of the GIT
Layer of dense connective tissue, contains nervous plexuses as well as main blood and lymph vessels
Describe the muscularis layer of the GIT
Two layers of smooth muscle: inner circular and outer longitudinal layer
Describe the serosa of the GIT
Loose connective tissue, adipose tissue and blood and lymph vessels surrounded by mesothelium
What type of epithelium lines the oesophagus?
Non-keratinised squamous epithelium
Describe the epithelium of the stomach
Single layered columnar epithelium with main invaginations that extend into the lamina propria (gastric pits)
What is the name for the folds in the stomach area and what is their function?
Rugae - to increase SA
What are the 4 sections of the stomach?
The cardia, fundus, body and pylorus