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Flashcards in Development of the Gut Deck (98):
1

Forms as a result of the lateral, cranial, and caudal body folds

Gut tube

2

Lead to the incorporation of the dorsal portion of the endodermal yolk sac into an endoderm lined tube
within the embryo (3rd to 4th week)

Lateral, cranial, and caudal body folds

3

The gut tube is limited at the
1.) Cranial end by>
2.) Caudal end by?

1.) Buccopharyngeal membrane
2.) Cloacal membrane

4

In the 4th week, the buccopharyngeal membrane ruptures and establishes communication with the

Ectodermally lined oral cavity

5

In the 7th week, the cloacal membrane ruptures and establishes communication with the

Ectodermally lined anal canal

6

Initially, the gut tube retains its communication with the yolk sac by way of the

Vitelline duct

7

The vitelline duct narrows and subsequently is obliterated, thus separating the

Gut tube from yolk sac

8

Failure of the vitelline duct to obliterate can result in an open communication between the gut tube and the outside environment at the umbilicus. This is called a

Vitelline fistula

9

An open communication between the gut tube and the outside environment at the umbilicu

Vitelline Fistula

10

Meconium and fecal material may emerge at the umbilicus through a

Vitelline Fistula

11

What three things may result from incomplete closure of the vitelline duct?

1.) Vitelline cyst
2.) Vitelline sinus
3.) Meckel's diverticulum

12

A cyst within a fibrous remnant of the vitelline duct

Vitelline cyst

13

Similar to a cyst, except it communicates with the external environment

Vitelline sinus

14

A diverticulum from the wall of the ileum that does not communicate with the outside environment

Meckel's Diverticulum (ileal diverticulum)

15

Reportedly present in 2-3% of the population and is usually asymptomatic, although it may become inflamed and it may contain ectopic tissue

Meckel's diverticulum

16

When present, Meckel's diverticulum is usually found on the antimesenteric side of the illeum, about

2-3 ft. from the ileocecal junction

17

When ectopic tissue is present, it is often gastric mucosa. What does the gastric mucosa secrete that may be the cause of inflammation?

HCL

18

If the lateral body folds do not completely meet and fuse correctly, there may be a weakness of the anterior abdominal wall which may lead to

Gastroschisis

19

Provides an open communication between the abdominal cavity and the outside environment

Gastroschisis

20

Gastroschisis typically occurs to the

Right of the umbilicus

21

Failure to recanalize the gut tube results in a segment of the gut tube without a

Lumen (called atresia)

22

Atresia occursmost commonly in the

Duodenum

23

Evidence suggests that atresias in the jejunum and ileum are the result of vascular insult to a segment of the gut tube during

Development

24

Obstruction of the digestive tract distal to the stomach results in severe vomiting after feeding because of the
inability to

Empty the stomach

25

The presence or absence of bile in vomit will tell us if the obstruction is

Proximal (non-bilious) or Distal (bilious) to the entry of the common bile duct

26

The gut tube is divided into the

Pharynx, foregut, midgut, and hindgut

27

The portion of the gut tube from the buccopharyngeal membrane to the respiratory diverticulum

Pharynx

28

Envaginations of the pharynx include the

Pharyngeal pouches, thyroglossal duct, and respiratory diverticulum

29

Abnormalities in the formation of the respiratory
diverticulum may result in

Esophageal atresia, esophageal stenosis, or tracheoesophageal fistula

30

Prevents the fetus from swallowing amniotic fluid and results in an abnormally high volume of amniotic fluid (polyhydramnios)

Esophageal atresia

31

May result in thyroglossal cyst (median cervical cyst),
lingual thyroid or other ectopic thyroid tissue

Thyroglossal duct abnormalities

32

The foregut is supplied by the celiac trunk and vagus nerve and gives rise to the

Esophagus, stomach, and part of the duodenum

33

Which part of the duodenum does the foregut giverise to?

1st part and proximal portion of the 2nd part

34

Envaginations of the foregut give rise to

Liver, gall bladder, and the pancreas

35

The midgut is supplied by the

Superior mesenteric artery and vagus nerve

36

The midgut gives rise to what 7 things?

1.) Part of the duodenum
2.) jejunum
3.) Ileum
4.) cecum
5.) appendix
6.) ascending colon
7.) proximal 2/3 of transverse colon

37

What part of the duodenum does the midgut give rise to?

distal portion of 2nd part, and 3rd and 4th parts

38

The hindgut is supplied by the

Inferior mesenteric artery and pelvic splanchnic nerves

39

The hindgut gives rise to what 5 things?

1.) distal 1/3 of transverse colon
2.) descending colon
3.) sigmoid colon
4.) rectum
5.) upper part of anal canal

40

Gives rise only to the epithelium of the gut tube, epithelium of the gut tube derivatives and glands derived from the epithelium

Endoderm

41

The other layers of the gut tube organs (e.g. smooth muscle, connective tissue) are derived from

Splanchnic mesoderm

42

The inner layer of the lateral plate mesoderm

Splanchnic meoderm

43

During the formation of the gut tube by body folding, the splanchnic mesoderm is carried inward along with the endodermal gut tube and becomes the

Peritoneal covering of the gut tube and the mesenteries

44

Peritoneal membranes that connect the visceral peritoneum with the parietal peritoneum

Mesenteries

45

Serve as "bridges" to carry blood vessels, lymphatics and nerves from retroperitoneal positions to the gut tube

Mesenteries

46

Serves as the pathway for branches of the abdominal aorta to provide blood supply to the gut, as well as a pathway for veins, lymphatics, and nerves

Dorsal mesentery

47

The only vessel to traverse the ventral mesentery is the

Umbilical vein

48

The adult remnant of the umbilical vein is the

Ligamentum teres

49

The adult mesenteries derived from the ventral mesentery are the

Falciform ligament, and the lesser omentum

50

Contains the ligamentum teres

Falciform ligament

51

Contians the common bile duct, the proper hepatic artery, and the portal vein

Lesser omentum

52

What are two adult mesenteries derived from the dorsal mesentery?

1.) Greater omentum (includes gastrocolic ligament)
2.) Mesentery proper (attached to jejunum and ileum)

53

Evaginates from the endodermal lining of the ventral wall of the gut tube in the region of the 2nd portion of the duodenum

-enters the ventral mesentery

Hepatic Diverticulum

54

The site of the hepatic diverticulum marks the termination of the

Foregut

55

What do the distal and proximal ends of the hepatic diverticulum become?

1.) Distal: liver and gall bladder
2.) Proximal: biliary duct system

56

The portion of the ventral mesentery covering the liver becomes the

Visceral peritoneum of the liver

57

The portion of the ventral mesentery between the liver and gut tube becomes the

Lesser omentum

58

The portion of the ventral mesentery between the liver and ventral body wall becomes the

Falciform ligament

59

The part of the liver that comes into contact with the diaphragm and is not covered by peritoneum is the

Bare area of the liver

60

The hepatic veins exit the liver and enter the inferior vena cava through the

Bare area

61

The bare area is surrounded by a reflection of peritoneum from visceral peritoneum of the liver onto the parietal peritoneum on the diaphragm. This is called the

Coronary ligament

62

Develops from two pancreatic diverticula (buds) which evaginate from the endodermal lining of the gut tube in the region of the 2nd portion of the duodenum

Pancreas

63

Arises in common with the hepatic diverticulum

Ventral pancreatic bud

64

Initially grows into the ventral mesentery but subsequently leaves the ventral mesentery, rotates around the gut tube to enter the dorsal mesentery

Ventral pancreatic bud

65

The ventral pancreatic duct gives rise to which three things?

1.) Major pancreatic duct (of Wirsung)
2.) lower portion of the head of the pancreas
3.) Uncinate process

66

Gives rise to the minor pancreatic duct (of Santorini) and the upper portion of the head of the pancreas and the neck, body and tail of the pancreas

Dorsal pancreatic duct

67

Malrotation of the ventral pancreatic bud may result in

-may present symptoms of bowel obstruction

Anular pancreas

68

A ring of pancreatic tissue which surrounds the second portion of the duodenum

Anular pancreas

69

Develops in the dorsal mesentery of the stomach (dorsal megogastrium)

Spleen

70

Rrises from cells of the mesentery which delaminate and migrate into the plane between the layers of the mesentery

Spleen

71

The mesentery covering the spleen becomes the

Visceral peritoneum of the spleen

72

The mesentery between the spleen and the gut tube becomes the

Gastrosplenic ligament

73

The mesentery between the spleen and the dorsal body wall becomes the

Splenorenal ligament

74

Most of the splenorenal ligament fuses to become

Parietal peritoneum

75

The blood supply to the spleen (the splenic artery) reaches the spleen by passing within the

Splenorenal ligament

76

Does not develop from an envagination of the gut tube and thus is not connected to the gut by a duct

-not part of the digestive system

Spleen

77

Most of the gut tube retains only a dorsal mesentery. The absence of a ventral mesentery allows for

Mobility of the gut

78

Parts of the gut tube (most of duodenum, ascending colon, descending colon, part of rectum) fuse with the body wall by way of fusion of

Visceral peritoneum with parietal peritoneum

79

This results in the organ becoming secondarily retroperitoneal and the visceral peritoneum covering the organ being renamed

Parietal peritoneum

80

The mesentery attaching to the organ also is renamed parietal peritoneum and the vessels within the mesentery thus become

Secondarily retroperitoneal

81

Rotates 90 degrees around its own long axis such that the dorsal side rotates to the left and the ventral side rotates to the right

Abdominal foregut

82

This results in the dorsal border of the stomach becoming the left border which becomes the

Greater curvature of the stomach

83

The ventral border of the stomach becomes the right border which becomes the

Lesser curvature of the stomach

84

For this reason, the dorsal mesentery of the stomach is attached to the greater curvature and becomes the

Greater omentum

85

The ventral mesentery of the stomach is attached to the lesser curvature and becomes the

Lesser omentum

86

This rotation also creates the omental bursa (lesser sac). The communication between the lesser sac and the greater sac is the

Epiploic formamen (of Winslow)

87

The midgut develops an intestinal loop which herniates into the

Umbilical cord (6th week)

88

While in the umbilical cord and during retraction from the umbilical cord, the midgut rotates 270 degrees around an anteroposterior axis marked by the

Superior mesenteric artery

89

This rotation results in the jejunum being on the left and the ileum and cecum being on the

Right

90

It also causes the colon to assume the shape of an

Inverted U

91

Failure of the intestinal loop to completely retract from the umbilical cord (usually completely retracted by the 12th week), results in

Omphalocele

92

When the loops of bowel are found within the umbilical cord and are separated from the amniotic fluid by
the amniotic membrane covering the umbilical cord

Omphalocele

93

The abdominal organs are within the umbilical cord and therefore covered by the amniotic membrane and
separated from the amniotic fluid with

Omphalocele

94

The abdominal organs are outside of the umbilical cord, are not covered by the amniotic membrane and are in contact with amniotic fluid with

Gastroschisis

95

What is more common (1/4000 vs. 1/8000) omphalocele or gastroschisis?

Omphalocele

96

Is more often associated with chromosomal
abnormalities and other congenital defects and has an increased incidence with older maternal age (>40 years)

Omphalocele

97

Less frequently associated with other abnormalities and has an increased incidence with younger maternal age (<20 years)

Gastroschisis

98

Babies with omphalocele have a much poorer survival rate, primarily because of associated defects of the

Heart and Kidneys

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