Drive - embryology Flashcards
What layer of the embryo is mainly responsible for the development of the GI tract?
Endoderm
What does endoderm give rise to? (associated with the GI tract) =3
Epithelial lining of the digestive tract
Hepatocytes of the liver
Endocrine and exocrine cells of the pancreas
What does the visceral mesoderm give rise to? (associated with the GI tract) = 2
Muscle, connective tissue and peritoneal components of the wall of the gut
Connective tissue for the glands
When does the mouth form?
At 4 weeks
When does the anus form?
At 7 weeks
How many pharyngeal arches are there and what are these called?
5 arches: 1, 2, 3, 4, 6
What provides innervation to the 1st pharyngeal arch?
Mandibular branch of the trigeminal nerve.
What provides innervation to the 2nd pharyngeal arch?
Facial nerve
What provides innervation to the 3rd pharyngeal arch?
Glossopharyngeal nerve
What provides innervation to the 4th pharyngeal arch?
Superior laryngeal nerve branch of the vagus nerve
What provides innervation to the 6th pharyngeal arch?
Recurrent laryngeal nerve branch of the vagus nerve
What is a mesentery?
Double layers of peritoneum that surrounding an organ and connect it to the body wall
What is a ligament?
Double layers of peritoneum which pass from one organ to another (or from one organ to the body wall)
What do mesenteries and ligaments provide?
Provide pathways from blood vessels, lymphatics and nerves to go to and come from the abdominal viscera.
What part of the GI tract is ventral mesentery and dorsal mesentery located?
Ventral mesentery = Foregut only
Dorsal mesentery = Foregut, midgut and hindgut
What does the free lower margin of the ventral mesentery contain? (3)
Hepatic artery, portal vein and bile duct
What causes the formation of the lesser omentum and the falciform ligament?
The development of the liver in the ventral mesentery.
What causes the signature curvatures of the stomach?
The dorsal wall (the part attached to the dorsal mesentery) grows faster than the ventral wall (the part attached to the ventral mesentery).
During what week is the lesser sack formed and why?
7th week - as the stomach rotates 90o clockwise.
Through what do the greater and lesser sacs communicate?
epiploic foramen
From what do hepatocytes originate from?
Endoderm
From what do the exocrine and endocrine cells of the pancreas originate from?
Endoderm
