Digestion

Question 1

The ______ of the primordial gut gives rise to the gut.

Answer 1

endoderm

Question 2

During body folding (week ___), endoderm from the dorsal portion of ___ ___ is incorporated into the embryo.

Answer 2

4; yolk sac

Question 3

The yolk sac forms the _____ (innermost/outermost) lining of the primitive gut tube.

Answer 3

innermost

Question 4

The endoderm of the primordial gut gives rise to the gut, ____ lining, and ___ of the GI tract.

Answer 4

epithelial; glands

Question 5

what forms during head folding?

Answer 5

foregut

Question 6

what forms during tail folding

Answer 6

hindgut

Question 7

The primordial gut is initially closed at its cranial end by the ____ membrane, and at its caudal end by the ____ membrane.

Answer 7

oropharyngeal; cloacal

Question 8

During ____ (lateral/caudal) folding, the yolk sac ____ (endoderm/ectoderm) is incorporated as embryonic ____(midgut/hindgut).

Answer 8

lateral; endoderm; midgut

Question 9

The oropharyngeal membrane ruptures at __ weeks and the cloacal membrane ruptures at __ weeks to allow for swallowing of the amniotic fluid.

Answer 9

4; 8

Question 10

The omphaloenteric, or _____, duct is the connection between the ___ ___ and the ___-gut.

Answer 10

Vitelline; yolk sac; mid-gut

Question 11

what forms the smooth muscle and connective tissues of the GI tract, including the mesenteries?

Answer 11

splanchnic mesoderm

Question 12

The _____ (endoderm/ectoderm/mesoderm) forms the peritoneum and mesenteries.

Answer 12

mesoderm

Question 13

what is a double layer of peritoneum that suspends an organ from the body wall?

Answer 13

Mesentery

Question 14

which serous membrane lines the abdominal cavity?

Answer 14

parietal peritoneum

Question 15

which serous membrane lines organs?

Answer 15

visceral peritoneum

Question 16

T/F. Parietal peritoneum is derived from splanchnic mesoderm.

Answer 16

False. Parietal peritoneum is derived from somatic mesoderm.

Question 17

Visceral peritoneum is derived from which mesoderm, splanchnic or somatic?

Answer 17

splanchnic

Question 18

The ventral mesentery is resorbed ____ (superior/inferior) to foregut.

Answer 18

inferior

Question 19

T/F. The dorsal mesentery is more widespread than the ventral mesentery.

Answer 19

true.

Question 20

T/F. The ventral mesogastrium forms the falciform ligament and the lesser omentum

Answer 20

True.

Question 21

What two ligaments can be located in the lesser omentum?

Answer 21

hepatoduodenal and hepatogastric ligaments

Question 22

what migrates into the walls of the GI tract to form the enteric nervous system during week 5-7)?

Answer 22

neuroectoderm/neural crest cells

Question 23

Which vessel supplies the foregut? midgut? and hindgut?

Answer 23

celiac trunk; SMA; IMA

Question 24

what is the arterial supply to the pharynx?

Answer 24

pharyngeal arch aa

Question 25

what are the foregut derivates?

Answer 25

pharynx, lower respiratory system, esophagus, stomach, proximal 1/2 duodenum, liver, gallbladder, biliary system, and pancreas

Question 26

During week 4, what is the respiratory diverticulum that appears on the ventral side of the foregut that will become the trachea, respiratory tree and lungs?

Answer 26

tracheo-bronchical diverticulum (lung bud)

Question 27

T/F. As the stomach enlarges caudal to the esophagus, its ventral side expands faster than the greater curvature.

Answer 27

False. The DORSAL side = greater curvature The VENTRAL side = lesser curvature.

Question 28

In which direction does the stomach rotate?

Answer 28

90o Clockwise (if looking from superior view)

Question 29

The ventral side (lesser curvature) ends up on which side of the body? How does this affect the vagus nerve distribution?

Answer 29

VENTRAL = right | LEFT vagus supplies the ventral stomach

Question 30

The dorsal side (greater curvature) ends up on which side of the body? How does this affect the vagus nerve distribution?

Answer 30

DORSAL = left | RIGHT vagus supplies the dorsal stomach

Question 31

As the stomach rotates, which direction is the dorsal mesogastrium carried?

Answer 31

left

Question 32

the rotation of the dorsal mesogastrium to the left creates what space?

Answer 32

omental bursa (lesser sac of the peritoneum)

Question 33

The omental bursal is a recess between what two areas?

Answer 33

stomach and posterior abdominal wall

Question 34

what structure is carried to the left when the dorsal mesogastrium rotates?

Answer 34

spleen

Question 35

what structure is formed when the dorsal mesogastrium begins to form a flap over the small intestines?

Answer 35

greater omentum

Question 36

T/F. The greater omentum is a single layer that hangs over the transverse colon.

Answer 36

False. It is a double layer over the transverse colon.

Question 37

The ____ (proximal/distal) 1/2 of the duodenum is in the foregut and therefore supplied by the __ __.

Answer 37

proximal; celiac trunk

Question 38

The ___ (proximal/distal) 1/2 of the duodenum is in the midgut and therefore is supplied by the _ _ _.

Answer 38

distal; SMA

Question 39

what structure represents the split between the foregut and the midgut?

Answer 39

major duodenal papilla (opening for the pancreatic and common bile ducts)

Question 40

What direction does the duodenum rotate with the stomach?

Answer 40

clockwise

Question 41

T/F. The duodenum and pancreas are not retroperitoneal.

Answer 41

False. The distal duodenum and pancreas becomes pressed against the posterior abdominal wall.

Question 42

What is lost when the duodenum and pancreas move retroperitoneal?

Answer 42

their dorsal mesenteries fuse with parietal peritoneum and are lost.

Question 43

The duodenum and pancreas are _____ retroperitoneal.

Answer 43

secondarily

Question 44

The ____ diverticulum emerges ventrally from ____ (endoderm/ectoderm) of distal foregut (week4) and grows superiorly toward the ____ ___ to give rise to the liver, gall bladder and bile ducts.

Answer 44

hepatic; endoderm; septum transversum (future diaphragm)

Question 45

T/F. The liver, gall bladder, biliary tree and pancreas all develop as endodermal diverticula from the distal foregut.

Answer 45

True.

Question 46

What are the names of the two endodermal buds that emerge from the pancreas?

Answer 46

dorsal and ventral buds

Question 47

T/F. As the duodenum rotates, the dorsal bud swings clockwise and fuses with the ventral bud.

Answer 47

False. The VENTRAL bud rotates and fuses with the dorsal bud.

Question 48

The structures of the pancreas does the ventral bud form?

Answer 48

uncinate process and inferior portion of the head of the pancreas

Question 49

What is the structure called that forms from the distal portion of the dorsal bud duct and the ventral bud duct?

Answer 49

main pancreatic duct

Question 50

T/F. The main pancreatic duct forms from the proximal dorsal bud duct.

Answer 50

False. The accessory pancreatic duct forms from the proximal dorsal bud duct.

Question 51

T/F. The ventral bud of the pancreas develops in two portions.

Answer 51

True.

Question 52

If the ventral bud portions dont fuse during rotation, each portion may wrap around the duodenum and obstruct it. What condition is this?

Answer 52

Annular pancreas

Question 53

what are the midgut derivatives?

Answer 53

distal 1/2 duodenum, jejunum, ileum, cecum and appendix, ascending colon, and proximal 2/3 transverse colon

Question 54

The midgut forms a __-shaped loop.

Answer 54

U

Question 55

The vitelline duct is where the ____ limb and ___ limb meet.

Answer 55

cranial; caudal

Question 56

What three structures does the cranial limb of the midgut include?

Answer 56

distal duodenum, jejunum, proximal ileum

Question 57

what five structures does the caudal limb of the midgut include?

Answer 57

distal ileum, cecum, appendix, ascending colon, and prox 2/3 transverse colon

Question 58

What leads to temporary herniation of midgut loop into the proximal umbilical cord during weeks 6 - 10 of development? What is this condition called?

Answer 58

insufficient room in the abdominal cavity. Physiological umbilical hernia

Question 59

If an umbilical hernia persist after birth, what is it called?

Answer 59

congenital omphalocoele

Question 60

What is noted in a newborn with congenital omphalocoele?

Answer 60

viscera covered by amnion and WITHIN proximal umbilical cord

Question 61

What condition is often associated with chromosomal abnormalities and results in high mortality?

Answer 61

congenital omphalocoele

Question 62

T/F. Gastrochisis involves the umbilical cord.

Answer 62

False. It does NOT involve the umbilical cord. It results from herniation thru the anterior body wall.

Question 63

when does the first midgut rotation occur?

Answer 63

week 6

Question 64

what is the direction of the 1st midgut rotation? What is the axis of rotation?

Answer 64

90o counter-clockwise. | SMA

Question 65

when does the 2nd midgut rotation occur?

Answer 65

week 10 as the intestine return to the abdomen

Question 66

T/F. The cranial limb return first during the 2nd midgut rotation.

Answer 66

True.

Question 67

what is the direction of the second midgut rotation?

Answer 67

180o counter clockwise

Question 68

T/F. The ascending and descending colon are secondarily retroperitoneal.

Answer 68

true.

Question 69

what four structures are secondarily retroperitoneal?

Answer 69

distal duodenum pancreas ascending colon descending colon

Question 70

define secondarily retroperitoneal

Answer 70

originally developed within the peritoneal cavity, but shifted into retroperitoneal position due to GI growth and rotation.

Question 71

What structure is primarily retroperitoneal?

Answer 71

kidneys

Question 72

what structures are intraperitoneal?

Answer 72

(stomach and) prox duodenum jejunum, ileum transverse colon sigmoid colon

Question 73

If there is no 2nd midgut rotation, the ___ (cranial/caudal) limb returns first and occupies the left side of the abdominal cavity known as left-sided colon.

Answer 73

caudal

Question 74

what is the result if the 2nd midgut rotation is reversed?

Answer 74

midgut and hindgut are in normal position except duodenum is ventral to the transverse colon (not retroperitoneal)

Question 75

what condition results from abnormal rotation that caused intestinal loop twisting around mesenteric attachment sites?

Answer 75

vovulus

Question 76

define stenosis.

Answer 76

the abnormal narrowing of a lumen/orifice (tubular organ or structure)

Question 77

what condition results when a body lumen or orifice is abnormally closed or absent?

Answer 77

atresia

Question 78

what is an abnormal passageway between two organs/vessels or between an organ and the external environment?

Answer 78

Fistula

Question 79

what are the hindgut derivates?

Answer 79

distal 1/3 transverse colon, descending colon, sigmoid colon, rectum and superior portion of the anal canal

Question 80

what two structures are derived from the posterior portion of the cloaca after it is partitioned by the urorectal septum?

Answer 80

rectum and superior portion of the anal canal

Question 81

A ____ septum grown inferiorly toward the cloacal membrane, dividing it into ____ and ____ membranes.

Answer 81

urorectal; urogenital; anal

Question 82

The urorectal septum partitions the cloaca into the ___ ___ (ventrally) and ___ ___ (dorsally).

Answer 82

urogenital sinus; anorectal canal

Question 83

what causes hindgut fistulas?

Answer 83

if the urorectal septum fails to completely separate the hindgut from the urogenital sinus or if the cloaca is too small

Question 84

T/F. Hirschsprung's disease (aganglionic megacolon) results when neural crest cells fail to migrate and form the enteric nervous system.

Answer 84

True.

Question 85

The aganglionic portion ____ (dilates/constricts) causing the bowel to distend proximal the (dilation/constriction) leading to severe constipation and failure to thrive.

Answer 85

constricts; constriction