Development of the Digestive System Flashcards Preview

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Flashcards in Development of the Digestive System Deck (52):
1

the connection b/w the gut and yolk sac during embryonic lateral body folding is known as ?

vitelline duct

2

epithelial lining and the glands of the GI tract are derivatives of what ?

endoderm

3

smooth musculature and conenctive tissue of the GI tract are derivatives of ?

splanchnic mesoderm

4

parietal peritoneum is of what derivative ?

somatic mesoderm

5

visceral peritoneum is of what derivative

splanchnic mesoderm

6

what is the peritoneum

serous membrane lining the abdominal cavity and organs

7

what is a mesentery

double layer of peritoneum that suspends organs from the body wall

8

what is the derivative of dorsal mesentery

splanchnic mesoderm

9

what is the derivative of ventral mesentery

splanchnic mesoderm

10

what type of body folding results in mesenteries

lateral folding

11

which mesentery is split/divided because of the development of the liver

ventral mesogastrium

12

which mesentery becomes the greater omentum

dorsal megogastrium

13

what is the ectodermal contribution to the GI tract

neural crest cells migrate and become the enteric nervous system

14

what are the 3 main divisions of the GI tract, and where are those divisions

foregut - esophagus to mid duodenum
midgut - mid duodenum to proximal 2/3 transverse colon
hindgut - distal 1/3 of transverse colon to asshole

15

what is the basis of how the different regions of the GI tract are divided ?

based upon blood supply

16

what artery supplies the foregut

celiac trunk a.

17

what artery supplies the midgut

superior mesenteric a.

18

what artery supplies the hindgut

inferior mesenteric a

19

all arterial supply to the GI tract are branches off what main artery

dorsal aorta

20

what are some of the foregut derivatives

pharynx, lower resp. system, esophagus, stomach, proximal 1/2 of duodenum

21

what is the special name of the endodermal lung bud on the ventral side of the foregut

respiratory diverticulum or tracheo-bronchial diverticulum

22

what side of the foregut becomes to the greater curvature and what side does it face after curvature

dorsal side, will be on left

23

what type of rotation does the stomach undergo

90 degree clockwise rotation

24

what is the recess behind the stomach created by the 90 degree rotation that allows the stomach to expand during eating

omental bursa

25

what are the organs that are secondarily retroperitoneal (behind the abdominal cavity) ? what causes this to happen ?

duodenum and pancreas
-shifting of stomach 90 CW causes them to turn

26

what endodermal outpouch gives rise to the liver, gall bladder, and bile ducts

hepatic diverticulum

27

what organ develops from 2 seperate endodermal buds, one dorsal and one ventral then eventually fuse

pancreas

28

the unicate process is + inferior portion of the head of the pancreas are derivatives from what bud of the pancreas

ventral bud

29

the main pancreatic duct is made from ?

distal dorsal bud duct + ventral bud duct

30

the accessory pancreatic duct is made form ?

proximal dorsal bud duct

31

what is the condition of annular pancreas

rare condition where ventral bud develops and fuses early causing an obstructive ring around the duodenum = vomiting bile

32

what are some of the midgut derivatives

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

33

what is a physiological umbilical herniation and when does this ovvur ?

temporary herniation of intestines in midgut loop into the proximal umbilical cord around week 6-10
-NORMAL cuz intestines forming faster than body cavity

34

what is congenital omphalocoele

persisting umbilical herniation w/in proximal umbilical cord

35

what is gastrochisis

hernia of small int. that doesnt involve umbilical cord

36

explain how the midgut loop undergoes 270 degree rotation

1st part - 90 degree CCW while midgut loop still in proximal umbilical cord
2nd part - 180 degree CCW rotation as intestines return to abdomen cavity

37

what is the axis of rotation during the rotation of the midgut

superior mesenteric a. (SMA)

38

what parts of the midgut become secondarily retroperitoneal after rotation

ascending colon and descending colon

39

kidneys are primary or secondarily retroperitoneal

primarily meaning developed w/in peritoneal cavity and remained in the peritoneal cavity

40

what is the end result in a case of non rotation of the midgut

Normal 1st rotation BUT NO 2nd rotation
-small intestines on right
-Lg. intestines on left or Left sided colon

41

what is the end result of a reversed rotation of the midgut

Normal 1st rotation BUT reveresed 2nd rotation
-All in normal posistion EXCEPT duodenum is ventral to transverse colon (usually function normally)

42

what is volvulus and what causes it ?

abnormal rotation of midgut intestinal loop = bowel obstruction leading to multiple disorders

43

stenosis

abnormal narrowing/constriction

44

atresia

abnormally closed or absent lumen

45

fistula

abnormal passageway b/w 2 structures

46

explain recanalization of the midgut loop

intestines are temporarily plugges at week 6 then
RECANALIZE by epithelial cells dying off eventually reforming lumen at week 8

47

what is Meckel's Diverticulum

-most common GI malformaiton (especially males)
-vitelline duct persists as fingerlike outpouching of ileum potentially causing a fistula b/w belly button and intestine =shit out of belly button

48

what are the hindgut derivatives

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

49

the rectum and anal canal are both derivatives of what

cloaca or cloacal membrane

50

what divides the cloacal membrane into seperate urogenital membranes and anal membranes

urorectal septum

51

how is the partitioning of the cloaca into the urogenital sinus and anorectal canals organized on the body

urogenital membrane ventrally
anorectal canal dorsally

52

what is Hirschsprungs disease

-Aganglionic megacolon
nueral crest cells fail to migrate and form enteric nervous system
-causes constant constriction of bowel cuz no nervous system to relax = blocks colon and severe constipation