DIGESTIVE SYSTEM DEVELOPMENT AND ANATOMY Flashcards
epithelium of the GIT and parenchyma of glands develops from…
The endoderm
muscle, connective tissue and peritoneum develops from…
The mesoderm
Mesenteries are…
double layers of peritoneum
The stomach rotates … clockwise around its longitudinal axis.
90 degrees
Bile starts being produced from… week
12th
The liver has an important function from 6th week to 7th month:
Hematopoyetic function
From 4th to 6th week, the … has the hematopoyetic function before the livers gets this function.
Splachnic mesoderm from the yolk sac
The liver is originated from the…
Endoderm (mainly), but part of the sinusoids from the liver are developed from the mesoderm.
Bile duct enters in the dudodenum through the…
Major dudodenum papilla
Uncinate process is developed from…
The ventral pancreas
Accessory pancreatic duct is a branch from…
Main pancreatic duct
Lining the abdominal cavity, we have the … mesoderm
Somatic/parietal
Lining the gut tube, we have the … mesoderm
Visceral or splanchnic
What are the mesenteries or mesos?
Double layers of mesoderm which connect the viscera to the walls.
The gut tube is connected to the parietal mesoderm by the…
Mesentery/mesos
Retroperitoneal viscera such as… are fixed and do not move. They are attached to muscles of the posterior abdominal wall such as…
Kidneys
Quadratus lumborum, psoas muscle, transversus abdominis
Intraperitoneal viscera is recovered by … and it is attached to the wall by the …
Visceral peritoneum, mesos.
Mesenteries are also pathways which allow … to access the viscera
Vessels, nerves and lymphatics
Intraperitoneal viscera have some degree of movement (T/F)
True
What kind of viscera is initially Intraperitoneal but becomes retroperitoneal?
2ary retroperitoneal viscera
Example of 2ary retroperitoneal viscera
Pancreas. It will become retroperitoneal and fixed as it loses its mesentery.
Which 3 branches gives the aorta at the level of the abdominal cavity?
- 1st branch for the derivatives of the foregut: CELIAC TRUNK
- 2nd for midgut derivatives: SUPERIOR MESENTERIC ARTERY
- 3rd for hindgut derivatives: INFERIOR MESENTERIC ARTERY
FOREGUT DERIVATIVES
Abdominal esophagus, stomach, 1st and 2nd portion duodenum, pancreas, liver and gallbladder
The derivatives of the foregut are supplied by the….
CELIAC TRUNK
MIDGUT DERIVATIVES + ARTERY AND NERVE WHICH SUPPLIES THEM
Remaining duodenum, jejunum, ileum, cecum/appendix, ascending colon, 2/3 TC
Superior mesenteric artery and vagus nerve
HINDGUT DERIVATIVES + ARTERY AND NERVE SUPPLY
- Remaining 1/3 of the TC
- Descending colon
- Sigmoid colon
- SUPERIOR portion of the rectum
Inferior mesenteric artery+ pelvic splanchnic nerves (S2-S4)
ABDOMINAL AORTA BRANCHES
Parietal branches of the abdominal aorta
Inferior phrenics, lumbar, common iliac, median sacral
Visceral branches abdominal aorta
Celiac trunk (T12-foregut)
Superior mesenteric artery (L1-midgut)
Inferior mesenteric artery (L3-hindgut)
Renal arteries (L1)
Gonadal arteries (L2)
At the level of …, the IVC enters the thorax through the diaphragm.
T8
What is the ENTEROHEPATIC CIRCULATION?
Blood from the digestive system will not go directly into the IVC, but first through the liver.
Portal hepatic vein is formed by…
The junction of splenic vein and superior mesenteric vein
The ICV passes … to the liver
Posterior
GI VENOUS DRAINAGE - PORTAL SYSTEM
A drug taken orally can change its conformations and functions because…
It is metabolised in the liver (1st hepatic effect)
Drugs administered rectally ….
will not pass through the enterohepatic circulation (they are drained into inferior rectal veins, these go directly into the common iliac veins and the IVC).
PS INNERVATION DERIVATIVES FOREGUT AND MIDGUT
Vagus nerve
PS INNERVATION DERIVATIVES HINDGUT
Pelvic splanchnic nerves (S2-S4)
SYMPATHETIC FIBERS arise from …
Lateral horn of the levels T1 to L2
Sympathetic innervation GI SYSTEM
- For foregut and midgut derivatives: greater, lesser and inferior splanchnic nerves.
- For HINDGUT derivatives: lumbar splanchnic nerves.
They synapse in PREAORTIC GANGLIA.
Sympathetic nerves of the GI TRACT will follow ….
The abdominal aorta to reach their corresponding derivatives.
Hiatus of ICV in diaphragm
T8
Esophageal hiatus in diaphragm
T10
Aortic hiatus in diaphragm
T12
Structures passing through the diaphragm
Phrenic nerves, azygos and hemiazygos (which transition into ascending lumbar veins), inferior phrenic arteries
…. Veins drain the derivatives of the midgut and HINDGUT into the portal system
Superior and inferior mesenteric
All the venous drainage from the GI tract enters into the … to become metabolised, and through the … into the IVC
liver, hepatic veins
Primitive gut is formed between the … week of development
4th and 5th
epithelium of the GIT and parenchyma of glands is derived from the …
Endoderm
muscle of the viscera, connective tissue and peritoneum is derived from…
The mesoderm
From the ventral wall of the foregut arises the respiratory diverticulum, which will be separated from the esophagus by the…
TRACHEOESOPHAGEAL SEPTUM
Communication between esophagus and trachea causes:
Esophageal atresia and/or traqueoesophageal fistula
1/3000 births
Prenatal: polyhydramnios
Postnatal: regurgitation
after feeding
Recanalization is a process in which…
There is apoptosis of the growing epithelium/endoderm during the 5th and 6th week
Incomplete recanalization causes…
Stenosis
If the esophagus does not grow properly, the stomach protrudes into the thoracic cavity causing…
CONGENITAL HIATAL HERNIA
Mesenteries are…
double layers of peritoneum
The stomach rotates 90ºclockwise around its longitudinal axis, leaving the … side facing anteriorly and the … portion facing posteriorly.
Left, right
That is why the left vagus nerve comes anteriorly and the right one posteriorly.
The greater curvature of the stomach is cause because…
The posterior wall of the stomach grows faster.