Development of the Abdomen Flashcards by Lucas Bracero

during third week of development what does the embryo become and what are the layers called

trilaminar disc
three layers of disc (germ layers)
ectoderm (continuous with amnion)
mesoderm (single horseshoe shaped canal- intraembryonic coelom)
endoderm (continuous with yolk sac)

How well did you know this?

Not at all

Perfectly

what directions does the embryo fold and what does this do

craniocaudally
laterally
canals and part of yolk sac are incorporated into embryo

How well did you know this?

Not at all

Perfectly

what is the result of embryonic folding

gut tube (endoderm surrounded by support mesoderm) suspended inside cavity b/w a dorsal and a ventral connection to the body wall

How well did you know this?

Not at all

Perfectly

by the 5th week of development there is a single gut tube suspended by what?

THE dorsal mesentery

How well did you know this?

Not at all

Perfectly

Major developmental events of the gastrointestinal system occur when in embryonic life (and what marks the beginning and the end

between
4th week- initial dilation of stomach
and 10th week- return of herniated loops of intestine

How well did you know this?

Not at all

Perfectly

foregut derivatives are suppled by what artery

celiac artery

How well did you know this?

Not at all

Perfectly

foregut derivaties are (name the organs)

esophagus
stomach (gaster)
proximal half of duodenum
liver (hepar)
gall pladder
pancrease

How well did you know this?

Not at all

Perfectly

the respiratory diverticulum is an outgrowth of what section of the gut and forms what?

foregut outgrowth

forms: larynx, trachea, and lungs

How well did you know this?

Not at all

Perfectly

the foregut includes what (name of the gut and its extension from where to where)?

pharyngeal gut from buccopharyngeal membrane to respiratory diverticulum

How well did you know this?

Not at all

Perfectly

the foregut forms part of what cavity and what other structures (not abdominal organs)

oral cavity
pharynx
directs of the pharyngeal arches

How well did you know this?

Not at all

Perfectly

midgut derivatives are supplied by what artery

Superior Mesenteric Artery

How well did you know this?

Not at all

Perfectly

midgut derivaties (name the organs)

distal half of duodenum
jejunum and ileum
cecum and vermiform appendix
ascending colon
proximal 2/3 of transverse colon

How well did you know this?

Not at all

Perfectly

hindgut derivatives are supplied by what artery

inferior mesenteric artery

How well did you know this?

Not at all

Perfectly

hindgut derivaties (name the organs)

distal 1/3 of transverse colon
descending and sigmoid coon
superior 1/2 of rectum

How well did you know this?

Not at all

Perfectly

the esophagus is formed by what?

a partition that develops in the foregut tube called the tracheoesophageal septum

How well did you know this?

Not at all

Perfectly

formation of esophagus begins as what?

respiratory diverticulum (lung buds) that expand caudally forming the esophagotracheal ridge- this later forms the septum that separates pharynx into esophagus and trachea

How well did you know this?

Not at all

Perfectly

the stomach starts as?

dilation (swelling) in tube (foregut)

How well did you know this?

Not at all

Perfectly

what surface of the stomach grows faster?

dorsal surface grows faster than ventral surface

How well did you know this?

Not at all

Perfectly

what surface becomes the greater curvature and why

dorsal surface

because it grows faster than the ventral surface

How well did you know this?

Not at all

Perfectly

rotation of stomach during development does what?

causes the original ventral surface to move to the right and the original dorsal surface to move to the left
this makes the greater curvature end up on the left side in adults

How well did you know this?

Not at all

Perfectly

rotation of stomach during development results in what structure?

lesser sac (omental bursa)

How well did you know this?

Not at all

Perfectly

the composition of vagal trunks (left being anterior and right being posterior) can be explained by?

90 degree rotation of stomach on its longitudinal axis

How well did you know this?

Not at all

Perfectly

the liver develops as what?

a bud (hepatic diverticulum) off the foregut

How well did you know this?

Not at all

Perfectly

the liver grows in what direction pushing through what?

grows out ventrally

pushes through the inferior part of the septum transversum (later becomes ventral mesentery)

How well did you know this?

Not at all

Perfectly

as the liver grows it does what (in relation to abdominal cavity) and this causes what

bulges into abdominal cavity pulls the septum transversum with it causes liver to be suspended b/w foregut and anterior abdominal wall by ventral mesentery (septum transversum)

the septum transversum (other than ventral mesentery) is a main component of what and is formed from what germ layer?

diaphragm | mesoderms

the falciform ligament (derived from what, connects what, carries what)

derived from ventral mesentery liver to anterior abdominal wall free margin carries umbilical vein (ligamentum teres)

lesser omentum (derived from what, what does it connect)

derived from ventral mesentery | connects liver to foregut

lesser omentum (named parts and what they connect)

hepatogastric ligament- liver to stomach | hepatoduodenal ligament- liver to duodenum (carries portal triad)

the septum transversum ultimately becomes what (in relation to liver and diaphragm)?

visceral peritoneum of liver | central tendon of diaphragm

the liver is enclosed in what?

visceral peritoneum of ventral mesentery

the part of the liver not covered by visceral peritoneum is called what

bare area

the gallbladder and ventral pancreatic bud arise from what?

hepatic diverticulum

dorsal pancreas develops as a bud off of what?

dorsal surface of developing duodenum

the common stay of the liver and gall bladder becomes what?

common bile duct

as the foregut rotates to the right what happens to duodenum

duodenum becomes C-shaped and ends up to the right of midline

as the foregut rotates to the right what happens to pancreas and bile duct and why

the pancreas and bile duct migrate dorsally | due to duodenum growing more quickly on the dorsal wall coupled with rotation

during what week do the two pancreatic buds fuse

6th week

the ventral pancreatic bud becomes what?

head and uncinate process

the dorsal pancreatic bud becomes what.

body and tail of pancreas

when the pancreatic buds fuse the ducts anastomose; what does each duct from each bud become (respectfully)

ventral bud- main pancreatic duct | dorsal bud- accessory pancreatic duct

Annular pancreas (what is it, what causes it, why is it significant)

rare congenital abnormality characterized by a ring of pancreatic tissue that encircles the descending portion of the duodenum thought to originate from incomplete rotation of the pancreatic ventral bud pancreatic tissue can constrict the duodenum and obstruct the intestine

Spleen (formation)

as an independent condensation of mesoderm between layers of the dorsal mesentery of the stomach

what abdominal organ is not an outgrowth of the gut

spleen

the part of the dorsal mesentery that extends posterior to the spleen does what

fuses to the posterior abdominal wall

the part of the dorsal mesentery between the spleen and the stomach becomes what?

gastrosplenic ligament

the confused part of the dorsal mesentery that extends posterior to the spleen becomes what?

splenorenal ligament

physiological umbilical herniation

normal | as the midgut elongates the intestinal loops project into the umbilical cord

Gastroschisis

ventral body wall defect that results in herniation of intestinal loops into the amniotic cavity due to failure of the body wall to close

Omphalocele

ventral wall defect | caused when parts of the guy tube that normally hornet into the umbilical cord fail to return to the abdominal cavity

when the intestines project into the umbilical cord what happens to the midgut?

rotates 90 degrees counter clockwise

what type of rotation does the midgut undergo (and around what)

90 degree counter clockwise rotation along the axis of the superior mesenteric artery and vitelline duct

the cecum forms as what?

a swelling on the distal (caudal) loop

as the intestines return to the abdomen during the 10th week what happens?

they rotate another 180 degrees counterclockwise

what is the total degrees of rotation the intestines undergo

270 degrees

where does the cecum end up after intestinal rotation

lower right

where does the proximal end of the intestine end up after rotation

upper left part of abdominal cavity | goes back first

Meckle's Diverticulum

persistence of vitelline duct | about 50 cm from ileocecal valve

what organs are secondarily retroperitoneal

2nd and 3rd parts of duodenum head and body of pancreas ascending colon descending colon

midgut-hindgut transition (where does it occur)

2/3 of the way through the transverse colon near the left colic (splenic) flexure

midgut-hindgut transition (where does it get blood)

superior and inferior mesenteric arteries via the marginal artery of Drummond

cloaca (what is it and where)

part of hindgut | just proximal to the cloacal membrane

the cloaca is divided into what?

``` urogenital sinus (anterior) anorectal canal (posterior) ```

what divides the cloaca

growing urogenital septum between the hindgut and allantois

proctodeum (what is it)

an indentation of the body wall | forms distal opening of tube as septum grows

what happens to the proctodeum as the septum grows

pushes inward toward the anorectal cannot form the distal opening of the tube

fully formed anal canal is derived from what

cloaca (part of embryonic hindgut) | proctodeum (part of body wall)

the separation of the two region of the anal canal is called what?

the pectinate line

below the pectinate line where does the anal canal receive blood and innervation from?

branches of internal iliac artery | innervated by spinal nerves

above the pectinate line where does the anal canal receive blood and innervation from?

inferior mesenteric artery | autonomic nerves

what about the anal canal is important in understanding a variety of clinical conditions from rectal cancer to hermorrhoids

knowing about dual innervation, blood supply, and lymphatic drainage