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

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

A

Gut tube

2
Q

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)

A

Lateral, cranial, and caudal body folds

3
Q

The gut tube is limited at the

  1. ) Cranial end by>
  2. ) Caudal end by?
A
  1. ) Buccopharyngeal membrane

2. ) Cloacal membrane

4
Q

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

A

Ectodermally lined oral cavity

5
Q

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

A

Ectodermally lined anal canal

6
Q

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

A

Vitelline duct

7
Q

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

A

Gut tube from yolk sac

8
Q

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

A

Vitelline fistula

9
Q

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

A

Vitelline Fistula

10
Q

Meconium and fecal material may emerge at the umbilicus through a

A

Vitelline Fistula

11
Q

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

A
  1. ) Vitelline cyst
  2. ) Vitelline sinus
  3. ) Meckel’s diverticulum
12
Q

A cyst within a fibrous remnant of the vitelline duct

A

Vitelline cyst

13
Q

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

A

Vitelline sinus

14
Q

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

A

Meckel’s Diverticulum (ileal diverticulum)

15
Q

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

A

Meckel’s diverticulum

16
Q

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

A

2-3 ft. from the ileocecal junction

17
Q

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

A

HCL

18
Q

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

A

Gastroschisis

19
Q

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

A

Gastroschisis

20
Q

Gastroschisis typically occurs to the

A

Right of the umbilicus

21
Q

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

A

Lumen (called atresia)

22
Q

Atresia occursmost commonly in the

A

Duodenum

23
Q

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

A

Development

24
Q

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

A

Empty the stomach

25
Q

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

A

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

26
Q

The gut tube is divided into the

A

Pharynx, foregut, midgut, and hindgut

27
Q

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

A

Pharynx

28
Q

Envaginations of the pharynx include the

A

Pharyngeal pouches, thyroglossal duct, and respiratory diverticulum

29
Q

Abnormalities in the formation of the respiratory

diverticulum may result in

A

Esophageal atresia, esophageal stenosis, or tracheoesophageal fistula

30
Q

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

A

Esophageal atresia

31
Q

May result in thyroglossal cyst (median cervical cyst),

lingual thyroid or other ectopic thyroid tissue

A

Thyroglossal duct abnormalities

32
Q

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

A

Esophagus, stomach, and part of the duodenum

33
Q

Which part of the duodenum does the foregut giverise to?

A

1st part and proximal portion of the 2nd part

34
Q

Envaginations of the foregut give rise to

A

Liver, gall bladder, and the pancreas

35
Q

The midgut is supplied by the

A

Superior mesenteric artery and vagus nerve

36
Q

The midgut gives rise to what 7 things?

A
  1. ) Part of the duodenum
  2. ) jejunum
  3. ) Ileum
  4. ) cecum
  5. ) appendix
  6. ) ascending colon
  7. ) proximal 2/3 of transverse colon
37
Q

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

A

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

38
Q

The hindgut is supplied by the

A

Inferior mesenteric artery and pelvic splanchnic nerves

39
Q

The hindgut gives rise to what 5 things?

A
  1. ) distal 1/3 of transverse colon
  2. ) descending colon
  3. ) sigmoid colon
  4. ) rectum
  5. ) upper part of anal canal
40
Q

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

A

Endoderm

41
Q

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

A

Splanchnic mesoderm

42
Q

The inner layer of the lateral plate mesoderm

A

Splanchnic meoderm

43
Q

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

A

Peritoneal covering of the gut tube and the mesenteries

44
Q

Peritoneal membranes that connect the visceral peritoneum with the parietal peritoneum

A

Mesenteries

45
Q

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

A

Mesenteries

46
Q

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

A

Dorsal mesentery

47
Q

The only vessel to traverse the ventral mesentery is the

A

Umbilical vein

48
Q

The adult remnant of the umbilical vein is the

A

Ligamentum teres

49
Q

The adult mesenteries derived from the ventral mesentery are the

A

Falciform ligament, and the lesser omentum

50
Q

Contains the ligamentum teres

A

Falciform ligament

51
Q

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

A

Lesser omentum

52
Q

What are two adult mesenteries derived from the dorsal mesentery?

A
  1. ) Greater omentum (includes gastrocolic ligament)

2. ) Mesentery proper (attached to jejunum and ileum)

53
Q

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

A

Hepatic Diverticulum

54
Q

The site of the hepatic diverticulum marks the termination of the

A

Foregut

55
Q

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

A
  1. ) Distal: liver and gall bladder

2. ) Proximal: biliary duct system

56
Q

The portion of the ventral mesentery covering the liver becomes the

A

Visceral peritoneum of the liver

57
Q

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

A

Lesser omentum

58
Q

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

A

Falciform ligament

59
Q

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

A

Bare area of the liver

60
Q

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

A

Bare area

61
Q

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

A

Coronary ligament

62
Q

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

A

Pancreas

63
Q

Arises in common with the hepatic diverticulum

A

Ventral pancreatic bud

64
Q

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

A

Ventral pancreatic bud

65
Q

The ventral pancreatic duct gives rise to which three things?

A
  1. ) Major pancreatic duct (of Wirsung)
  2. ) lower portion of the head of the pancreas
  3. ) Uncinate process
66
Q

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

A

Dorsal pancreatic duct

67
Q

Malrotation of the ventral pancreatic bud may result in

-may present symptoms of bowel obstruction

A

Anular pancreas

68
Q

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

A

Anular pancreas

69
Q

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

A

Spleen

70
Q

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

A

Spleen

71
Q

The mesentery covering the spleen becomes the

A

Visceral peritoneum of the spleen

72
Q

The mesentery between the spleen and the gut tube becomes the

A

Gastrosplenic ligament

73
Q

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

A

Splenorenal ligament

74
Q

Most of the splenorenal ligament fuses to become

A

Parietal peritoneum

75
Q

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

A

Splenorenal ligament

76
Q

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

A

Spleen

77
Q

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

A

Mobility of the gut

78
Q

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

A

Visceral peritoneum with parietal peritoneum

79
Q

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

A

Parietal peritoneum

80
Q

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

A

Secondarily retroperitoneal

81
Q

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

A

Abdominal foregut

82
Q

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

A

Greater curvature of the stomach

83
Q

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

A

Lesser curvature of the stomach

84
Q

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

A

Greater omentum

85
Q

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

A

Lesser omentum

86
Q

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

A

Epiploic formamen (of Winslow)

87
Q

The midgut develops an intestinal loop which herniates into the

A

Umbilical cord (6th week)

88
Q

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

A

Superior mesenteric artery

89
Q

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

A

Right

90
Q

It also causes the colon to assume the shape of an

A

Inverted U

91
Q

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

A

Omphalocele

92
Q

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

A

Omphalocele

93
Q

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

A

Omphalocele

94
Q

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

A

Gastroschisis

95
Q

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

A

Omphalocele

96
Q

Is more often associated with chromosomal

abnormalities and other congenital defects and has an increased incidence with older maternal age (>40 years)

A

Omphalocele

97
Q

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

A

Gastroschisis

98
Q

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

A

Heart and Kidneys

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