Development Of The Gi Tract

Front 1

The early gut tube is formed by the incorporation of what embryological structure?

Back 1

Part of the yolk sac

Front 2

What is the role of the vitelline duct in the fetus?

Back 2

A connection between the gut tube and the yolk sac.

Front 3

What gene is in charge of the patterning of the regions of the digestive system?

Back 3

Homeobox genes

Front 4

In addition to regionalization, development of the gut tube involves what other characteristics?

Back 4

1. Rotation and folding for efficient packing
2. Histiogenesis of further maturation of the epithelial lining

Front 5

Epithelial lining and glands are derived from what?

Back 5

Endoderm

Front 6

The Lamina propria, muscularis mucosa,submucosa, muscularis externa and seorsa/adventia are derived from what?

Back 6

Splanchnic mesoderm

Front 7

The primitive gut tube is divided into 3 parts, each with an associated artery--what are the parts?

Back 7

Foregut, midgut and hindgut

Front 8

What suspends the primitive tube from the dorsal and ventral body walls?

Back 8

Dorsal and Ventral mesentery (Diaphragm down)

Front 9

What are the derivatives of the foregut?

Back 9

Esophagus
Stomach and 1/2 duodenum
Liver
Gall bladder
Pancreas
Spleen

Front 10

What arty supplies the structures in the foregut?

Back 10

Celiac artery

Front 11

What separates the esophagus from the developing respiratory system?

Back 11

Tracheoesophageal septum

Front 12

What is the most common congenital malformation of the esophagus?

Back 12

Esophageal atresia, usually in combo with tracheoesophageal fistula

Front 13

Esophageal stenosis occurs because of what 2 abnormalities?

Back 13

Incomplete recanalization
Vascular abnormalities or compromised blood flow

Front 14

How is the lesser and greater curvature formed?

Back 14

The dorsal part of stomach grows faster causing greater and lesser.

Front 15

Describe the roation of the stomach and its effects on the vagus nerves.

Back 15

As gut tube grows, stomach undergos a clockwise 90 degree rotation to form the lesser sac. Left vagus=anterior, Right=posterior

Front 16

What is hypertropchic pyloric stenosis?

Back 16

Overgrowth of musculature at the sphincter regulating passage of food from the stomach into the duodenum.

Front 17

What type of vomiting is hypertrophic pyloric stenosis associated with?

Back 17

Non bilious projectile vomiting

Front 18

Non-bilious projectile vomiting tells us what about the location contents?

Back 18

Never made it pass the stomach due to lack of bile in the vomit.

Front 19

Hepatic diverticulum is an outgrowth of what part of the gut tube?

Back 19

Endoderm

Front 20

Hepatic diverticulum grows into the mesoderm of what septum?

Back 20

Septum transversum

Front 21

How are the hepatic sinusoids formed?

Back 21

Hepatic cords of cells coalesce around extraembryonic veins belonging to vitelline and umbilical systems.

Front 22

The liver divides the ventral mesentery into 2 parts, what are they?

Back 22

Falciform ligament and lesser omentum

Front 23

Ligamentum venosum is the firous remnant of what embrylogical structure?

Back 23

Ductus venosum

Front 24

Ligamentum teres hepatics is what obliterated structure?

Back 24

Umbilical vein

Front 25

The connection between liver and forgut narrows to become what structure?

Back 25

Bile duct

Front 26

What are the 2 outgrowths of the bile duct?

Back 26

gallbladder and cystic duct

Front 27

What is extrahepatic biliary atresia?

Back 27

Imcomplete recanalization leads to occlusion of the lumen of the bile duct, associated with jaundice, white clay-colored stool and dark urine.

Front 28

What is the treatment for extrahepatic hiliary atresia?

Back 28

Surgical correction or transplant

Front 29

Describe how the 2 pancreatic buds fuse together.

Back 29

Because the stomach and duodenum (thus pancreas) all rotate 90 degress, the ventral pancreatic bud spins around duodenum, bumps into dorsal bud, fuses to form adult pancreas.

Front 30

What is an annular pancreas?

Back 30

Ventral and dorsal pancreatic buds form a ring around the duodenum, presents with duodenal obstruction.

Front 31

What are the derivatives of the midgut?

Back 31

lower duodenum
jejunum
ileum
cecum and appendix
ascending colon
proximal 2/3 of transverse colon

Front 32

What are the derivatives of the midgut supplied by?

Back 32

Superior mesenteric artery

Front 33

The rest of the midgut forms a u-shaped loop that herniated into the umbilicus at what time?

Back 33

Week 6

Front 34

What occurs to the u-shaped loop of midgut in the 11th week?

Back 34

Midgut loop rotates 270 degrees counterclockwise around superior mesenteric artery before contents return to abdominal cavity.

Front 35

What is omphalocele?

Back 35

Midgut loop fails to completely return to the abdominal cavity.

Front 36

Malrotation of the midgut contents result in what abnormality?

Back 36

Abnormally positioned abdominal viscera

Front 37

What is gastroschisis?

Back 37

FAilure of anterior wall musculature to close during folding, gut not surround by protective membrane.

Front 38

What is a vitelline fistula?

Back 38

Remnant of vitelline duct persists as an open connection between intestinal lumen and external environment.

Front 39

What is an ilieal or Meckel's diverticulum?

Back 39

A remnant of vitelline duct persists as a blind pouch on the antimesenteric boarder of ileum.

Front 40

What are the hindgut derivatives?

Back 40

distal 1/3 of transverse colon, descending colon
sigmoid colon
rectum and anus

Front 41

What artery supplies the derivatives of the hindgut?

Back 41

Inferior mesenteric artery

Front 42

What is the cloaca?

Back 42

Endoderm-lined pouch located at the terminal end of the hindgut.

Front 43

The Urorectal septa paritions the cloaca into what?

Back 43

Anteriorly-bladder
posteriorly-rectum and upper anal canal

Front 44

What is aganglionic megacolon (Hirschsprung's disease) and what does it result in?

Back 44

Occurs when neural crest cells fail to migrate to walls of the colon, specifically myenteric plexus of the sigmoid colon and rectum. Results in loss of peristalsis, fecal retention and abdominal distention.

Front 45

What changes the size of the 2 original peritoneal cavities?

Back 45

Rotation

Front 46

What happens to any part of the gut tube that is in contact with the wall of the cavity once the gut has returned to abdominal cavity?

Back 46

It will lose its mesentery and will no longer be suspended in the abdominal cavity, making them secondarily retroperitoneal.

Front 47

Any organ developed outside the abdominal cavity which never had a mesentery to beign with is called what?

Back 47

Primary retroperitoneal

Front 48

Organs with a mesentary are called what?

Back 48

Intraperitoneal

Front 49

Failure of the cloaca to divide results in what malformations?

Back 49

Rectourethral fistula, rectoprostatic fistula, rectocloacal canal, rectovaginal fistula

Front 50

Preganglionic cells are found in what vertebral levels of the fore, mid, and hindgut?

Back 50

fore- T5-9
mid- T9-12
hind- T12-L2

Front 51

What are the splanchnic innervation of the fore, mid and hindgut?

Back 51

Greater splanchnic, lesser splanchnic, and least splanchnic, respectively.

Front 52

What are the Preganglionic cells of the parasympathetics for the fore, mid and hindgut?

Back 52

fore and mid=brainstem
hind= S2-S4

Front 53

What are the parasympathetic innervation of fore, mid and hind?

Back 53

fore and mid=vagus
hind=pelvic splanchnic nerves

Front 54

Where is the location of the ganglia of parasympathetics of fore, mid, and hind?

Back 54

Organ Walls

Front 55

What are the 2 types of esophageal replacements?

Back 55

colon interposition
gastric tube esophagoplasty

Front 56

What is gastric transposition?

Back 56

The whole stomach is freed, mobolized and moved into the chest.

Front 57

What is a duplication cysts of the duodenum?

Back 57

tubular structure with
an internal lining of gastrointestinal
epithelium, smooth muscle in its wall and
adherence to some portion of the alimentary
tract.

Front 58

What is apple peel atresia and where is it located?

Back 58

proximal jejunum
Intestine is short &
the portion distal to
the defect is coiled
around the
mesenteric remnant

Front 59

What are the features of Prune Belly?

Back 59

Common triad of features:
– Anterior abdominal wall:
musculature is deficient or
absent.
– Urinary tract anomalies (megaureters,
large bladder).
– Bilateral cryptorchidism
(undescended testicles).

Front 60

What is the difference between anorectal agenesis and anal agenesis?

Back 60

Anorectal- rectum ends as a blind pouch above the pelvic diaphragm
Anal-ends as a blind pouch below the pelvic diaphragm

Front 61

What is an imperforated anus?

Back 61

absence of misplaced anal opening