DIGESTIVE SYSTEM DEVELOPMENT AND ANATOMY Flashcards
(150 cards)
1
Q
epithelium of the GIT and parenchyma of glands develops from…
A
The endoderm
2
Q
muscle, connective tissue and peritoneum develops from…
A
The mesoderm
3
Q
Mesenteries are…
A
double layers of peritoneum
4
Q
The stomach rotates … clockwise around its longitudinal axis.
A
90 degrees
5
Q
Bile starts being produced from… week
A
12th
6
Q
The liver has an important function from 6th week to 7th month:
A
Hematopoyetic function
7
Q
From 4th to 6th week, the … has the hematopoyetic function before the livers gets this function.
A
Splachnic mesoderm from the yolk sac
8
Q
The liver is originated from the…
A
Endoderm (mainly), but part of the sinusoids from the liver are developed from the mesoderm.
9
Q
Bile duct enters in the dudodenum through the…
A
Major dudodenum papilla
10
Q
Uncinate process is developed from…
A
The ventral pancreas
11
Q
Accessory pancreatic duct is a branch from…
A
Main pancreatic duct
12
Q
Lining the abdominal cavity, we have the … mesoderm
A
Somatic/parietal
13
Q
Lining the gut tube, we have the … mesoderm
A
Visceral or splanchnic
14
Q
What are the mesenteries or mesos?
A
Double layers of mesoderm which connect the viscera to the walls.
15
Q
The gut tube is connected to the parietal mesoderm by the…
A
Mesentery/mesos
16
Q
Retroperitoneal viscera such as… are fixed and do not move. They are attached to muscles of the posterior abdominal wall such as…
A
Kidneys
Quadratus lumborum, psoas muscle, transversus abdominis
17
Q
Intraperitoneal viscera is recovered by … and it is attached to the wall by the …
A
Visceral peritoneum, mesos.
18
Q
Mesenteries are also pathways which allow … to access the viscera
A
Vessels, nerves and lymphatics
19
Q
Intraperitoneal viscera have some degree of movement (T/F)
A
True
20
Q
What kind of viscera is initially Intraperitoneal but becomes retroperitoneal?
A
2ary retroperitoneal viscera
21
Q
Example of 2ary retroperitoneal viscera
A
Pancreas. It will become retroperitoneal and fixed as it loses its mesentery.
22
Q
Which 3 branches gives the aorta at the level of the abdominal cavity?
A
- 1st branch for the derivatives of the foregut: CELIAC TRUNK
- 2nd for midgut derivatives: SUPERIOR MESENTERIC ARTERY
- 3rd for hindgut derivatives: INFERIOR MESENTERIC ARTERY
23
Q
FOREGUT DERIVATIVES
A
Abdominal esophagus, stomach, 1st and 2nd portion duodenum, pancreas, liver and gallbladder
24
Q
The derivatives of the foregut are supplied by the….
A
CELIAC TRUNK
25
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
26
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)
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ABDOMINAL AORTA BRANCHES
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Parietal branches of the abdominal aorta
Inferior phrenics, lumbar, common iliac, median sacral
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Visceral branches abdominal aorta
Celiac trunk (T12-foregut)
Superior mesenteric artery (L1-midgut)
Inferior mesenteric artery (L3-hindgut)
Renal arteries (L1)
Gonadal arteries (L2)
30
At the level of …, the IVC enters the thorax through the diaphragm.
T8
31
What is the ENTEROHEPATIC CIRCULATION?
Blood from the digestive system will not go directly into the IVC, but first through the liver.
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Portal hepatic vein is formed by…
The junction of splenic vein and superior mesenteric vein
34
The ICV passes … to the liver
Posterior
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GI VENOUS DRAINAGE - PORTAL SYSTEM
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A drug taken orally can change its conformations and functions because…
It is metabolised in the liver (1st hepatic effect)
37
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).
38
PS INNERVATION DERIVATIVES FOREGUT AND MIDGUT
Vagus nerve
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PS INNERVATION DERIVATIVES HINDGUT
Pelvic splanchnic nerves (S2-S4)
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SYMPATHETIC FIBERS arise from …
Lateral horn of the levels T1 to L2
41
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.
42
Sympathetic nerves of the GI TRACT will follow ….
The abdominal aorta to reach their corresponding derivatives.
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Hiatus of ICV in diaphragm
T8
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Esophageal hiatus in diaphragm
T10
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Aortic hiatus in diaphragm
T12
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Structures passing through the diaphragm
Phrenic nerves, azygos and hemiazygos (which transition into ascending lumbar veins), inferior phrenic arteries
48
…. Veins drain the derivatives of the midgut and HINDGUT into the portal system
Superior and inferior mesenteric
49
All the venous drainage from the GI tract enters into the … to become metabolised, and through the … into the IVC
liver, hepatic veins
50
Primitive gut is formed between the … week of development
4th and 5th
51
epithelium of the GIT and parenchyma of glands is derived from the …
Endoderm
52
muscle of the viscera, connective tissue and peritoneum is derived from…
The mesoderm
53
From the ventral wall of the foregut arises the respiratory diverticulum, which will be separated from the esophagus by the…
TRACHEOESOPHAGEAL SEPTUM
54
Communication between esophagus and trachea causes:
Esophageal atresia and/or traqueoesophageal fistula
1/3000 births
Prenatal: polyhydramnios
Postnatal: regurgitation
after feeding
55
Recanalization is a process in which…
There is apoptosis of the growing epithelium/endoderm during the 5th and 6th week
56
Incomplete recanalization causes…
Stenosis
57
If the esophagus does not grow properly, the stomach protrudes into the thoracic cavity causing…
CONGENITAL HIATAL HERNIA
58
Mesenteries are…
double layers of peritoneum
59
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.
60
The greater curvature of the stomach is cause because…
The posterior wall of the stomach grows faster.
61
In stomach development, the … is going to move downwards while the …. moves upwards.
Cardiac portion, pyloric portion.
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The stomach is connected and attached by…
Mesogastriums
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The liver arises and develops in the… mesogastrium
Ventral
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The pancreas appears within the … mesogastrium
Dorsal
66
The spleen develops from…
The mesoderm within the dorsal mesogastrium
67
Secondary retroperitoneal structures
Duodenum and pancreas
68
Behind the stomach appears a space, just dorsal to it, which corresponds to …
The omental bursa/lesser sac.
69
The lesser peritoneal sac and the greater peritoneal sac connect at…
FORAMEN OF WINSLOW (located posterior to the portal vein)
70
Dorsal mesogastrium grows and gives rise to…
The greater omentum (fat accumulates at the level of the greater omentum).
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The greater omentum is 4 layers of mesoderm, separated in 2 and 2 by the space. In the end, the … will become very reduced and small so the 4 layers willl become in contact.
omental bursa space
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The liver is not mobile, the …. become ligaments.
mesenteries
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Tumours in the …. are difficult for surgery
Lesser sac
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The greater omentum in the adult hangs from…., the lesser is attached to the … and connects it to the …
greater curvature, lesser curvature, liver
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The 2 double layers of dorsal mesoderm come in contact forming a 4 layered….
Greater omentum
76
Bike starts to be secreted … week
12th
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Liver arises from a liver bud which protrudes into…
The ventral mesogastrium
80
Ventral mesogastrium will divide into:
- Piece which connects stomach to liver:…
- Piece which connects liver to the ventral wall:….
- Gastrohepatic omentum/lesser omentum
- Falciform ligament
81
During development, the liver has…
Hematopoietic function
82
Other functions of the liver
Accumulate glucose in the form of glycogen, produce albumin, carry out protein metabolism, produce and secrete bile.
83
The bile is stored at the…, and it reaches the duodenum through the…
gallbladder, common bile duct
84
Together, … and … duct join the pancreatic duct to form the …. which enters the duodenum
hepatic, cystic, common bile duct
85
The pancreas originates from 2 buds: the … and … pancreatic bud.
The duodenum rotates to the right and forms a C-shaped loop, carrying with it the …. and the … into the dorsal mesentery.
The ventral pancreas arises from the …. Therefore its duct, the main pancreatic duct, will remain connected to the hepatic and cystic ones to enter the duodenum.
The dorsal pancreas’s duct will persist as a little …, which functions when the other is blocked.
- ventral, dorsal
- ventral pancreas, common bile duct
- common bile duct
- accessory pancreatic duct
86
The main pancreatic duct opens through the … into the 2nd portion of the duodenum, so both hepatic and pancreatic secretions enter here to participate in digestion.
Common bile duct
87
At the level of the … , a line marks the separation between the derivatives of the foregut and the derivatives from the midgut. It is also the point at which the main pancreatic duct + bile duct drain into the duodenum.
We also find the …., point at which the accessory pancreatic duct drains into the duodenum in case of blockage of the main one.
major duodenal papilla or Ampulla of Vater
minor duodenal papilla
88
2ary retroperitoneal organs
Pancreas and duodenum
89
90
Midgut begins …. and ends at the …
inferior to the major duodenal papilla , junction between the proximal 2/3 and distal 1/3 of the TC.
91
Midgut includes…
Part of the duodenum, jejunum and ileum, cecum, appendix, ascending colon and the proximal 2/3 of the TC.
92
Midgut derivatives are supplied by…
Branches of the superior mesenteric artery
93
The midgut is connected to the abdominal wall by a double layer of mesoderm:
Dorsal mesentery (through which the artery accesses to supply the structures).
94
Physiological umbilical hernation occurs the … week
Reduction of physiological midgut hernia occurs the … week
- 6th
- 10th
95
Scheme of midgut development
96
Anomalies of the midgut
Non-rotation causes:
-Left side colon
97
Anomalies of the midgut
Midgut volvolus is caused because of…
Twisting of intestines
98
Anomalies of the midgut
If the second rotation is done clockwise instead of counter-clockwise, the … compresses the colon
SUPERIOR MESENTERIC ARTERY
99
… is an anomaly in about 2-4% of the population and is cause by the persistence of the vitelline duct (connection with the yolk sac)
100
If the abdominal musculature does not close properly, part to the small intestine loops to herniate into the umbilicus causing…
UMBILICAL HERNIA (repaired easily)
101
Failure of the reduction of the physiological umbilical herniation into the abdominal cavity at the 10th week is called …
OMPHALOCELE
102
If at the 4th week, during the lateral folding of the embryo, the walls do not close properly, part of the visceral in the abdominal cavity can herniate into the amniotic cavity and they will be bathed by amniotic fluid. This condition is known as…
GASTROSCHISIS (severe)
103
HINDGUT begins ….(after the junction between the proximal 2/3 and the distal 1/3 of the TC) and ends midway through the…
Colic/splenic flexure, anal canal
104
HINDGUT includes:
Last third TC, descending and sigmoid colon, rectum, upper part of the anal canal.
105
HINDGUT is supplied by the…
Inferior mesenteric artery
106
Urorectal septum grows caudally and separates the cloaca into:
And the cloacal membrane into:
It also forms the …, muscles at the pelvic floor
-allantois anteriorly
- rectum and anal canal posteriorly
- urogenital membrane
- anal membrane (proctodeum)
-perineum
107
Cloacal membrane will give rise to the last portion of the anal canal:
PROCTODEUM
108
The first 2/3 of the anal canal will derive from the …
HINDGUT (endoderm in origin, IMA, ANS)
109
The last 1/3 of the anal canal is derived from the …
PROCTODEUM (an invagination of ectoderm from the cloacal membrane, inferior and middle rectal veins, somatic innervation).
110
The anal membrane will be ruptured at…
8th week
111
Incorrect development of the urorectal septum causes:
Imperforate anus (persistent anal membrane), recrovaginal fistula, fistula (communication) between ureters and rectum, rectal atresia (cierre)
112
If there is not migration of the neural crest cells and the large intestine has no PS ganglia, it becomes dilated causing…
MEGACOLON or Hirsprung disease
113
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Superior mesenteric artery arises at…
L1
115
116
Jejunum has …. at the mucosa
Prominent folds (for absorption) and lymphoid nodules
117
Parts of the JEJUNUM
118
The ileum does not have the … the jejunum has
Prominent folds
119
Cecum and appendix are …peritoneal
Intra
120
Ascending colon is …peritoneal
Retro
121
Transverse colon is …peritoneal
Intra
122
Sigma is …peritoneal
Intra
123
Origin of inferior mesenteric vein
Posterior to pancreas
124
Rectum begins anterior to … level
S3 (at the level of rectosigmal junction)
125
The end of the rectum is at the …
Tip of the coccyx
126
Peritoneum in females covers…
Uterus and the rectum partially (sac of Douglas)
127
128
129
Continuity between lesser and greater sac is done by the…
OMENTAL FORAMEN
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131
large apron-like peritoneal fold that
attachs to the greater curvature of the
stomach and first part of the duodenum.
Greater omentum
Remember that it is It consists of a double
sheet of peritoneum, folded on itself so that it
has four layers
132
The greater omentum fuses with the…
Transverse mesocolon
133
Greater omentum drapes inferiorly over the … and the ….
transverse colon, coils of the jejunum and ileum
134
Two-layer peritoneal omentum. It extends from the lesser curvature of the stomach and the first part of
the duodenum to the inferior part of the liver
Lesser omentum
135
Lesser omentum is divided in … and … ligaments
Hepatoduodenal and hepatogastric
136
137
Mesentery: suspends small intestine loops from the …
Posterior wall
138
139
Innervation of the peritoneum
THERE IS NO MOTOR INNERVATION AS THERE IS NO MUSCLE
- Visceral afferents: pain travels with sympathetic fibers for thoracic or lumbar splanchnic nerves. Distension with PS fibers from the vagus or pelvic splanchnic nerves.
- Somatic afferents: phrenic nerves and spinal nerves from T6-L2 roughly (well localised pain)
140
The foregut derivatives are supplied by the… trunk
Celiac
141
Right vagus nerve is … to esophagus, the left vagus nerve is …
Posterior, anterior
142
Abdominal esophagus starts at..
T10
143
144
145
*IMPORTANTE*
146
147
Left and right gastric veins drain into the…
PORTAL VEIN
148
Left gastro-omental vein drains into…
Splenic vein (which joins the superior mesenteric vein to form the portal vein)
149
Right gastro-omental vein drains into…
The superior mesenteric vein
150
STOMACH INNERVATION
- Sympathetic: Greater splachnic nerve (T5-T9) + Lesser splachnic nerve (TX-TXI) SYNAPSE IN CELIAC GANGLION
- PS: Vagus nerves
