Peritoneal cavity Flashcards
Outline the embryological origin of the gut
What is the primitive gut?
Between 2nd and 3rd week of development
Majority of the gut arises from the endoderm (most epithelium and glands of the digestive tract)
Muscular layers arise from the mesoderm and epithelium at extremities of tract (cranial and caudal) arise from the ectoderm.
The primitive gut is formed as a result of two folds (cranial-caudal and lateral). At 4 weeks the c-c ends are still closed by membranes: bucco-pharnygeal and cloacal. It is held in position by mesenteries
Describe the gut division
FOREGUT
Oesophagus, stomach, proximal half duodenum, liver and pancreas
MIDGUT
Distal half duodenum, jejunum, ileum, cecum, asc + 3/4 transverse colon
HINDGUT
1/4 transverse and descending and sigmoid colon and rectum
What is mesentery?
Formed by a double layer of peritoneum. Dorsal or ventral according to it relative position with respect to gut tube
Its role is to:
- suspend organs
- provide a pathways for blood, innervation, lymphatics
- ventral mesentery degenerates during development, except forgery
What is the difference between ventral and dorsal mesentery?
VENTRAL (front)
Exists at foregut only, gives rise to ligaments around liver, falciform ligament and lesser omentum.
DORSAL(back)
Attaches gut organs to posterior abdominal wall.
Gives rise to gastrosplenic ligament, leinorenal ligament, greater omentum, mesentery of small and large intestine
Describe the lesser omentum
The lesser omentum attaches to the lesser curvature of the stomach to the back of the liver and has a free edge
Where does the abdominal trunk lie?
What is the abdominal cavity called?
What is the relationship between the greater and lesser pelvis?
The trunk is below the diaphagm
Abdominopelvic (abdomen proper + greater pelvis)
Greater pelvis is continuous with lesser pelvis
Consider the abdominal muscles. Describe the external oblique
From the outer surface of lower eight ribs to the line alba, iliac crest and
