deck_1369849 Flashcards
What is the key stage which forms the ventral body wall and gets the gut within a cavity?
• Embryonic folding
What happens when the embryo folds laterally?
• Creates ventral body wall• Primitive gut becomes tubular
What happens when the embryo folds cranicaudally?
• Creates cranial a caudal pockets from yolk sac endoderm (beginning of primitive gut development)
What are the three embryonic divisions of the gut?
• Foregut• Midgut• Hindgut
What does the division of the regions of the foregut determine?
• It’s blood and nerve supply
Where is only opening in the developing embryo?
• Mid gut
How do the divisions of the gut tube help us?
• Gives us structures for blood supply and lymphatic drainage in the adult
What is the stomatodeum?
• Future mouth
What is the proctodeum?
• Future anus
What is the opening into the yolk sac?
Vitelline duct
What is the internal lining of the gut derived from?
• Endoderm
What is the external lining of the gut derived from? What does it become?
• Splanchnic mesoderm ○ Future musculature ○ Visceral peritoneum
Where is the primitive gut tube found?
• In intraembryonic coelom, suspended by a double layer of splanchnic mesoderm
Give 7 structures found in foregut
• Oesophagus• Stomach• Foregut• Pancreas,liver&gallbladder•Duodenum(proximaltoentranceofbileduct)
What is the blood supply of the foregut?
• Celiac trunk
Give 6 structures found in midgut
• Duodenum(distaltoentranceofbileduct)• Jejunum• Midgut• Ileum• Cecum• Ascendingcolon• Proximal 2/3 transverse colon
What is the blood supply of the midgut?
• Superior Mesenteric Artery• Superior Mesenteric Vein
Give 7 structures found in hindgut
• Distal1/3transversecolon• Hindgut• Descendingcolon• Sigmoidcolon• Rectum• Upperanalcanal• Internalliningofbladder&urethra
What is the blood supply of the hindgut?
• Inferior Mesenteric Artery• Inferior Mesenteric Vein
Why is embryonic distinction important in terms of arterial blood supply?
• Each segment receives blood supply from a distinct branch of the abdominal aorta
What structures receive a mixed blood supply?
• Those which develop close to the junction between foregut and midgut ○ Duodenum § Proximal to entry of bile duct - Gastroduodenal & superior pancreaticoduodenal artery § Distal to entry of bile duct - Inferior pancreatic duodenal artery (SMA) ○ Pancreas § Head - Superior pancreaticoduodenal artery (CT) § Inferior pancreaticduodenal artery (SMA)
What are the most important arterial trunks for the GI tract?
• The celiac trunk• The superior mesenteric artery• Abdominal aota• Inferior mesenteric artery
How is the intraembryonic coelom divided?
• By the diaphragm into abdominal and thoracic cavities• Peritoneum and peritoneal cavity
What is the mesoderm of the gut split into?
• Somatic mesoderm• Splanchnic mesoderm
What is the primitive gut surrounded by?
• Coelomic cavity
How is the abdominal wall formed?
• Two sides of the anterlateral wall meet in the linea alba• One opening is left, at the umbilicus
What makes up the three layers of the anterolateral abdominal wall?
• The external oblique• The internal oblique• The transversus abdominis
What muscle is located on the anterior aspect of the abdominal wall?
• Rectus abdominis
What structure is deep to all of the muscles of the abdominal wall?
The transversalis fascia
What lines the external surface of the abdominal wall?
• The superficial fascia
What do the muscles and fascia of the abdominal wall develop from?
• Somatic mesoderm
What is the inguinal canal?
• An oblique passage through the layers of the abdominal wall
What does the inguinal canal allow in males?
• Allows the passage of the developing testis into the scrotum
What is a common condition in the inguinal canal?
Hernia
What is found in the inguinal canal in women?
• The round ligament of the uterus and the iliinguinal nerve