Embryo Final

Front 1

Prenatal ultrasound showed polyhydramnios at 36 wks, and at birth the infant had excessive fluids in its mouth and difficulty breathing. What is the birth defect?

Back 1

esophageal atresia and/or tracheoesophageal fistula. 90% of time esophagus has blind pouch and fistula connects distal part w/ trachea. Abnormal partitioning of resp.diverticulum from foregut by tracheoesophageal septum

Front 2

Prenatal ultrasoun @ 20 wks shows midline mass w/ intestines and membrane bound. diagnosis & prognosis?

Back 2

omphalocele b/c failure of herniated bowel to return to abdominal cavity @ 10-12 weeks. Normally herniates into umbilical cord so it is covered by amnion. 25% die b4 birth, 40%-88% have assoc. anomalies, 15% chromosomal abnormalities. W/o other defects 100% survival:)

Front 3

Diff between omphalocele and gastroschisis

Back 3

omphalocele herniates into umbilical cord and is covered by amnion. gastroschisis herniates through abdominal wall defect and not covered by amnion and is exposed to amniotic fluid, survival rate is better b/c not assoc. w/ other anomalies

Front 4

Baby girl w/ meconium in vagina & no anal opening. Type of birth defect? Embryological origin?

Back 4

Imperforate anus w/ rectovaginal fistula, part of anorectal atresia complex. High anorectal atresia b/c fistual connects rectum to vagina. Prob. caused b/c cloaca too small so cloacal membrane was shortened posteriorly. Opening of hindgut shifted anteriorly. The smaller the cloaca is post. ant. the hindgut opening shifts, causing higher defect

Front 5

Pancreatic islets consist of alpha, beta and delta cells, which secrete glucagon, insulin and somatostatin. What are these cells derived from?

Back 5

Endoderm-pancreatic islets form as isolated clumps of cells that bud from endodermal tubules

Front 6

2 month old w/ sever jaundice, dark-colored urine and whilte clay-colored stool. What disorder is suspected?

Back 6

extrahepatic biliary atresia- failure of bile ducts to recanalize during development. Prevents bile from entering duodenum

Front 7

28 day old, projectile vomiting after feeding, no prob b4, small knot in rt. costal margin. what is disorder?

Back 7

hypertrophic pyloric stenosis- smooth muscle in pyloric region of stomach hypertrophies and obstructs passage of food, cause unknown

Front 8

what artery supplies foregut

Back 8

celiac artery

Front 9

most common anorectal malformation

Back 9

anorectal agenesis-rectum ends in blind sac above puborectalis muscle. Anal canal may form normally but does not connect w/ rectum. Is accompanied by various fistulas

Front 10

simple columnar or cuboidal epithelium lining the extrahepatic biliary ducts is derived from:

Back 10

enoderm- intrahepatic biliary ducts are also from endoderm

Front 11

4 day old, no defecation, normal feeding, no vomiting, normal anus, anal canal and rectum. Large fecal mass in colon, large release of flatus and feces after rectal exam. Dx?

Back 11

Colonic aganglionosis AKA Hirschsprung disease-lack of peristalsis in narrow segment sof colon distal to enlarged colon. Absense of parasympathetic glanglion celss in myenteric plexus

Front 12

what causes colonic agnaglionosis

Back 12

failure of neural crest migration

Front 13

where is the appendix derived from

Back 13

midgut-malrotation can cause it to be in upper abdomen-probs w/ appendicitis dx

Front 14

3 month old, swollen umbilicus that did not heal normally, drains secretions, passage of fecal material through umbilicus. most likely dx?

Back 14

ileal diverticulum AKA Meckel's diverticulum-remnant of vitelline duct persists. In this case fistula where contents of ileum can be discharged to surface of skin:(

Front 15

midgut loop normally herniates through primitive unblilical ring into exraembryonic coelom during week 6. Failure of intestinal loops to return to abd. cavity by week 11 results in what?

Back 15

omphalocele-they remain in umbilical cord covered by amnion

Front 16

Kupffer cells in adult liver are derived from what?

Back 16

mesoderm-they are macrophages

Front 17

what are hepatocytes and the epithelial lining of the intrahepatic biliary tree derived from

Back 17

endoderm

Front 18

simple columnar and stratified columnar epithelia lining the lower part of the anal canal is derived from what

Back 18

ectoderm

Front 19

baby born to woman w/ polyhydramnioa. Baby put in ICU b/c of repeated vomiting containing bile. Stomach distended, only small amts of meconium through anus. most likely dx?

Back 19

duodenal atresia-@ level distal to opening of common bile duct. Causes reflux of bile and its presence in vomitus. Polyhydramnios b/c duodenal atresia prevented passage of amniotic fluid into intestines for absorption

Front 20

____ and ___ folding of embryo causes portion of the _____ lined _____ to be incorporated into the embryo to from the _______

Back 20

cephalocaudal, lateral, endoderm, yolk sac, primitive gut

Front 21

yolk sac and allantois are _____ of embryo and _____ lined

Back 21

outside, endoderm

Front 22

what 2 parts of primitve gut are blind ended

Back 22

foregut, hindgut

Front 23

how is midgut connected to yolk sac

Back 23

via vitelline duct/yolk stalk

Front 24

location of pharyngeal gut

Back 24

from oropharyngeal membrane (buccopharyngeal membrane) to resp. diverticulum.(tracheobronchial diverticulum) it is part of foregut

Front 25

location of remainder of foregut

Back 25

caudal to pharyngeal tube, extends to liver outgrowth

Front 26

location of midgut

Back 26

caudal to liver bud, extends to jxn of rt. 2/3 and left 1/3 transverse colon

Front 27

location of hindgut

Back 27

left 1/3 transverse colon to cloacal membrane

Front 28

what is digestive tract lined by

Back 28

endoderm

Front 29

what do GI endoderm give rise to

Back 29

epithelial lining of gut, specific cells (parenchyma of glands), e.g. hepatocytes, exocrine and endocrine cells of pancreas

Front 30

what does stroma (CT of glands) arise from

Back 30

splanchnic mesoderm

Front 31

splanchnic mesoderm give what 3 components of all of the gut

Back 31

muscle, CT, peritoneum

Front 32

Initially, gut is in broad contact with the ______ of the _____ abd. wall

Back 32

mesenchyme, posterior

Front 33

By the 5th wk the _____ bridge narrows and the caudal part of the foregut, the midgut and the major part of the hindgut (caudal esophagus to major part of hindgut) are suspended from abd. wall by ____

Back 33

CT, dorsal mesentary

Front 34

how far does the dorsal mesentery extend

Back 34

from lower end of esophagus to cloacal region of hindgut

Front 35

What does the dorsal mesentery form in the region of the stomach

Back 35

dorsal mesogastrium AKA greater omentum

Front 36

in the region of the duodenum what does dorsal mesentery form

Back 36

mesoduodenum

Front 37

in region of colon what does dorsal mesentery form

Back 37

dorsal mesocolon

Front 38

in region of jejunal and ileal loops what does dorsal mesentery form

Back 38

mesentery proper

Front 39

where does the ventral mesentery exist

Back 39

caudal part of esophagus, stomach, upper part of duodenum

Front 40

what is the ventral mesentery derived from

Back 40

septum transversum

Front 41

Growth of the _____ into the ____ of the ______ divides the ventral mesentery into ____ and ______

Back 41

liver, mesenchyme, septum transversum, lesser omentum, falciform ligament

Front 42

when does the resp. diverticulum (lung bud) appear?

Back 42

4 wks

Front 43

where does the lung bud appear

Back 43

the ventral wall of the foregut at the border for the pharyngeal gut

Front 44

the _______ partitions the resp. diverticulum from the foregut

Back 44

tracheoesophageal septum

Front 45

the tracheoesophageal septume divides the forgut into what two parts

Back 45

resp. primordium and esophagus

Front 46

At fist the esophagust is short. How does it elongate?

Back 46

w/ descent of heart and lungs

Front 47

what is the muscular coat of the esophagus formed by

Back 47

surrounding splanchnic mesenchyme

Front 48

how does the stomach appear during the 4th week

Back 48

fusiform dilation of foregut

Front 49

why does stomach appearance and position change rapidly after 4th week

Back 49

differential rates of growth of various regions of stomach wall, changes in position of adjacent organs

Front 50

Stomach rotates ___ degrees ___ around its longitudinal axis, causing its left side to face ____ and rt side to face ____

Back 50

90, clockwise, anterior, posterior

Front 51

B/c of stomach rotation what happens to left vagus n

Back 51

become anterior vagus trunk

Front 52

The ____ wall of the stomach grows faster, forming the _____ and ____

Back 52

posterior, greater and lesser curvatures of stomach

Front 53

how is stomach attached to dorsal body wall

Back 53

dorsal mesogastrium

Front 54

how is stomach attached to ventral body wall

Back 54

ventral mesogastrium

Front 55

organ rotation tags along their assoc. _____

Back 55

membranes

Front 56

rotation around longitudinal axis pulls the dorsal mesogastrium to the left creating the ____

Back 56

omental bursa (lesser peritoneal sac)

Front 57

where is the ventral mesogastrium dragged to during rotation

Back 57

rt

Front 58

where does the spleen primordium appear during the 5th week

Back 58

mesodermal proliferation between the 2 leaves of the dorsal mesogastrium

Front 59

what happens to spleen attachments during stomach rotation

Back 59

dorsal mesogastrium lengthens, portion between spleen and dorsal midline swing to the left and fuses w/ parietal peritoneum of post. abd. wall.. Post. leaf of dorsal mesogastrium w/ the peritoneu along the line of fusion degenerate.

Front 60

After this, how is the spleen connected to the body wall

Back 60

it remains intraperitoneal, it is connected to the body wall in the region of the left kidney by the lienorenal ligaments and to the stomach by the gastrolienal ligament

Front 61

Initially the pancreas grows into the _____ but eventually its tail end extends into the _______

Back 61

dorsal mesoduodenum, dorsal mesogastrium

Front 62

how does the tail of pancreas become secondarily retroperitoneal?

Back 62

portion of dorsal mesogastrium fuses w/ dorsal body wall, tail of pancrease lies against that region, posterior leaf of dorsal mesogastrium and peritoneum of post. body wall degenerate along line of fusion, the tail of pancreas is then covered by peritoneum only on the anterior surface

Front 63

what does rotation of the stomach do to the dorsal mesogastrium

Back 63

it bulges down, extends over transverse colon as double-layered sac, becomes greater omentum

Front 64

what parts of the greater omentum fuse and where

Back 64

layers fuse to form a single sheet hanging from the greater curvature of stomach, the post layer of greater omentum also fuses w/ the mesentery of transverse colon

Front 65

the ____ and ____ form from the ventral mesogastrium, whihc itself is derived from the _____ of the ____

Back 65

lesser omentum, falciform ligament, mesoderm, septum transversum

Front 66

what 2 parts form the duodenum, where is the junction of these 2 parts

Back 66

terminal part of the foregut and the cephalic part of the midgut-jxn @ liver bud

Front 67

what is duodenum supplied by

Back 67

branches of celiac trunk and sup. mesenteric artery (from both foregut and midgut)

Front 68

what happens to the duodenum as the stomach rotates

Back 68

it becomes C-shaped and flaps/rotates to the right

Front 69

The duodenum slaps onto the post abd. wall w/ _____ which contacts the parietal peritoneum on post abd. wall, dorsal mesoduodenum fuses and disappears w/ the adjacent _____

Back 69

mesoduodenum, peritoneum

Front 70

This causes the duodenum (except for the duodenal cap) and the head of the pancreas to be fixed in a ____ position

Back 70

retroperitoneal

Front 71

when and how is the lumen of the duodenum obliterated

Back 71

2nd month by proliferation of cells in its wall

Front 72

what happens shortly after the duodenal canal is obliterated

Back 72

it is recanalized

Front 73

when, how and where does the liver primordium appear

Back 73

mid-3rd week, outgrowth of endodermal epithelium, from distal end of foregut

Front 74

The liver primordium outgrowth (______ or ______) consists of rapidly proliferating cells that penetrate the _________

Back 74

(hepatic diverticulum, liver bud)

Front 75

While hepatic cells continue to penetrate the septum transversum, the connection between the _______ and the ______ narrow forming the _____

Back 75

hepatic diverticulum, developing duodenum, bile duct

Front 76

how does the gall bladder and cystic duct form

Back 76

small ventral outgrowth formed by bile duct

Front 77

how does the lesser omentum and falciform ligaments form from the septum transversum

Back 77

liver cells invade septum transversum, liver bulges into abd. cavity, septum transversum becomes membranous and formess lesser omentum and falciform ligaments

Front 78

together the lesser omentum and flaciform ligament are termed the _____

Back 78

ventral mesentery

Front 79

_____ on the liver differentiates into the visceral peritoneum except on its cranial surface where it becomes the _____

Back 79

mesoderm, bare area

Front 80

what gives rise to the dorsal and ventral pancreatic buds

Back 80

endodermal lining of duodenum

Front 81

where does ventral pancreatic bud move due to rotation of stomach

Back 81

dorsally and lies immediately below and behind the dorsal bud (ventral pancreatic bud moves around right side of duodenum to be inferior to dorsal pancreatic bud

Front 82

what happens to the duct systems of the of the dorsal and ventral pancreatic buds

Back 82

they fuse in a specific fashion

Front 83

what happens to the distal part of the duct belonging to the dorsal pancreatic bud

Back 83

opens into duct of ventral pancreatic bud and becomes the main pancreatic ducts which opens via the major papilla

Front 84

what is main pancreatic duct formed from

Back 84

entire ventral pancreat duct and distal dorsal pancreatic duct

Front 85

what happens to the proximal part of the dorsal pancreatic bud

Back 85

is either obliterated or persists as a small channel (accessory pancreatic duct) which opens via minor papilla

Front 86

what happens to the original ventral pancreatic bud

Back 86

migrates and forms the uncinate process and inferior part of the head of pancreas in adult

Front 87

during the 5th week the midgut is suspended from the dorsal abdominal wall by a ____ mesentery and communicates w/ the yolk sac by way of the ______ or _____

Back 87

short, vitelline duct, yolk stalk

Front 88

what is the midgut supplied by

Back 88

superior mesentery artery and branches

Front 89

what causes the primary intestinal loop

Back 89

rapid elongation of midgut

Front 90

where does the primary intestinal loop communicate w/ the yolk sac

Back 90

at its apex by vitelline duct

Front 91

what does the cephalic limb of the loop develop into

Back 91

the distal part of the duodenum, the jujunum and part of the ileum

Front 92

what does the caudal limb of the loop develop into

Back 92

lower part of ileum, cecum appendix, ascending colon and the proximal 2/3 of transverse colon

Front 93

what causes the physiological herniation of gut tube

Back 93

rapid elongation of gut tube, growing size of liver, abdominal cavity too small

Front 94

during the herniation of gut tube where do it go and when

Back 94

into extraembryonic cavity in the umbilical cord during week 6

Front 95

what does the midgut rotate around

Back 95

superior mesenteric artery

Front 96

viewing in front, how far and in what direction does the midgut rotate

Back 96

counter clockwise 270 degrees

Front 97

does elongation occur during midgut rotation

Back 97

yes

Front 98

how much elongation occurs during herniation

Back 98

90 degrees

Front 99

how much elongation occurs during re-entry

Back 99

180 degrees

Front 100

when do the herniated loops return to the abdominal cavity

Back 100

10th week

Front 101

order of how intestines return to abdomen

Back 101

proximal jejunum returns first and settles to the left, the later returning portions settle progressively to the right

Front 102

when and how does cecal bud re-enter and find its position

Back 102

appears 6th week as dilation of caudal limb of primary intestinal loop, last part to re-enter abd., lies in upper rt. quad below rt lobe of liver, descends to right iliac fossa and forms appendix

Front 103

when cecum descends, what does it place on rt side of abd.

Back 103

ascending colon and hepatic flexure

Front 104

what do intestinal loops drag along

Back 104

mesenteries!

Front 105

how does ascending and descending colon become retroperitoneal

Back 105

mesenteries press against parietal peritoneum on post. abdominal wall fusion of repective layers

Front 106

what portions retain their free mesenteries

Back 106

lower end of cecum, sigmoid colon, appendix

Front 107

what does appendix and sigmoid colon attach by

Back 107

meso-appendix and meso-sigmoid colon

Front 108

what does the transverse mesocolon fuse w/

Back 108

posterior wall of greater omentum

Front 109

what happens when the mesentery of the ascending mesocolon fuses w/ the posterior abdominal wall

Back 109

the mesentery of the jejunoileal loops obtain a new line of attachment that extends from the area where the duodenum become intraperitoneal to the ileocecal jxn

Front 110

what does the hingut give rise to

Back 110

distal third of transverse colon, descending colon, sigmoid, rectum, upper part of anal canal

Front 111

what does the terminal portion of the hindgut enter into

Back 111

the posterior region of the cloaca: the primitve anorectal canal

Front 112

what enters into the anterior portion of the cloaca

Back 112

allantois :primitive urogenital sinus

Front 113

the cloaca is _____ lined covered at its ventral boundary by the surface ____

Back 113

endoderm, ectoderm

Front 114

what forms the cloacal membrane

Back 114

boundary between the endoderm and ectoderm

Front 115

what is the urorectal septum

Back 115

separating the region between the allantois and hindgut

Front 116

how is the urorectal septum derived

Back 116

merging of mesoderm covering the yolk sac and surrounding the allantois

Front 117

what does the tip of the urorectal septum advance toward

Back 117

the cloacal membrane

Front 118

what happens to the cloacal membrane during the 7th week

Back 118

it ruptures creating the anal opening and opening for urogential sinus

Front 119

what is the perineal body

Back 119

the tip of the urorectal septum between the urogenital sinus and anal opening

Front 120

How is the caudalmost region of anal canal closed off, when does it recanalize

Back 120

by proliferation of ectoderm, recanalized @ 9th week

Front 121

what is the caudal part of the anal canal from and what is it supplied by

Back 121

ectoderm, inferior rectal a, branch of pudendal a

Front 122

what is the cranial part of the anal canal from

Back 122

endoderm, superior rectal a, from inferior mesenteric a

Front 123

what is the jxn between the endodermal and ectodermal regions of the anal canal

Back 123

pectinate line just below anal columns

Front 124

what happens to the epithelium at the pectinate line

Back 124

changes from columnar to stratified squamous