Lecture 29: Abdomen II Guit Development Of Peritoneum

Question 1

foregut will form what structures (6)

Answer 1

stomach
liver
gallbladder
spleen
pancreas
1/5 duodenum

Question 2

midgut will form (6)

Answer 2

4/5 duodenum
jejunum
ileum
cecum
ascending colon
2/3 transverse colon

Question 3

midgut will form (6)

Answer 3

4/5 duodenum
jejunum
ileum
cecum
ascending colon
2/3 transverse colon

Question 4

hindgut will form (4)

Answer 4

1/3 transverse colon
descending colon
sigmoid colon
rectum

Question 5

intraembryonic coelem: 4 cavities

Answer 5

-1 pericardial cavity
-2 pericardioperitoneal canals
-1 peritoneal cavity

Question 6

peritoneum definition

Answer 6

single serous layer of flattened mesothelial cells supported by fibroelastic connective tissue that attaches to body wall, diaphragm and viscera

Question 7

peritoneum develops from

Answer 7

intraembryonic coelom

Question 8

parietal peritoneum derived from

Answer 8

parietal layer of lateral plate mesoderm (next to body wall)

Question 9

visceral peritoneum derived from

Answer 9

visceral layer of lateral plate mesoderm (next to organs)

Question 10

what structures are derived from the intraembryonic coelom (3)

Answer 10

-peritoneum
-visceral and parietal pericardium
-pleura

Question 11

peritoneal cavity definition

Answer 11

space enclosed by peritoneum

Question 12

peritoneal fluid secreted by what cells

Answer 12

-secreted by mesothelial cells into peritoneal cavity

Question 13

function/role of serous fluid in GI motility

Answer 13

-allows layers of peritoneum to glide against one another
-prevent viscera from attaching to abdominal wall

Question 14

unique feature of peritoneum (hint: clinical relevance)

Answer 14

-large, rapidly absorptive surface area
-toxins are readily absorbed, good environment for bacterial growth = peritonitis

Question 15

how does herniation of midgut during development lead to adult intestinal topography

Answer 15

• The size of the developing midgut is too large to be contained within the embryonic abdomen so it is forced to herniate into umbilical cord = makes for weak ventral abdominal wall in newborns and young animals
  -Herniates into peritoneal cavity ventrally, takes two layer of peritoneum = mesentery, completes a 270 degree rotation so large intestine becomes looped around small intestine
  -During this herniation the intestine drags vasculature, nerve supply, and lymphatics

Question 16

mesentery: developmental definition

Answer 16

2 layers of peritoneum that migrate together as the developing midgut migrates ventrally

Question 17

mesentery: definition

Answer 17

double layer of peritoneum that forms from invagination of peritoneum

Question 18

what structure suspends the midgut from the dorsal abdominal wall

Answer 18

dorsal mesentery

Question 19

root of the mesentery

Answer 19

peritoneal attachment between dorsal/great mesentery and dorsal abdominal wall

Question 20

what structures are suspended/supported by dorsal mesentery

Answer 20

-duodenum
-jejunum
-ileum

Question 21

intraperitoneal organs: definition

Answer 21

organs suspended from dorsal abdominal wall within peritoneal reflections

Question 22

retroperitoneal organs: definition

Answer 22

-organs directly joined to abdominal wall
-no mesentery or peritoneum dorsally

Question 23

3 retroperitoneal organs

Answer 23

kidneys
aorta
pancreas

Question 24

volvulus

Answer 24

loop of intestine and mesentery that becomes twisted
can lead to strangulated and obstructed bowel

Question 25

greater omentum functions

Answer 25

-prevent adhesions between abdominal viscera/organs and ventral abdominal wall -prevent spread of infection from perforations of intestines (seals off site of perforation)

Question 26

greater omentum definition

Answer 26

extended fold of dorsal mesogastrium -attaches greater curvature of stomach to dorsal body wall at pancreas -covers abdominal cavity

Question 27

lesser omentum definition

Answer 27

-spand distance from lesser curvature of stomach to porta of liver

Question 28

lesser omentum contains (3)

Answer 28

-portal vein -hepatic artery -bile duct

Question 29

foregut: blood supply, sympathetics, parasympathetics

Answer 29

-celiac trunk/artery -sympathetics: celiac ganglion -parasympathetics: vagus (CN X)

Question 30

midgut: blood supply, sympathetics, parasympathetics

Answer 30

-cranial mesenteric artery -sympathetics: cranial mesenteric ganglion -parasympathetics: vagus

Question 31

hindgut: blood supply, sympathetics, parasympathetics

Answer 31

-caudal mesenteric artery -sympathetics: caudal mesenteric ganglion -parasympathetics: pelvic splanchnic nerves

Question 32

4 layers of gut/GI

Answer 32

-mucosa -submucosa -muscularis externa -adventitia (rough) or serosa (smooth)

Question 33

3 layers of mucosa

Answer 33

-epithelium -lamina propria -muscularis mucosa

Question 34

lamina propria

Answer 34

CT layer with immune cells

Question 35

muscularis mucosa function and definition

Answer 35

contract mucosa multiple smooth muscle layers

Question 36

muscularis externa: 2 sublayers of muscle

Answer 36

inner circular outer longitudinal

Question 37

muscularis externa function

Answer 37

move luminal conent

Question 38

inner circular layer function

Answer 38

acts as series of sphincters to restrict luminal flow

Question 39

where is adventitia found (2 organs)

Answer 39

-esophagus -rectum, anal canal

Question 40

does esophagus have a lamina propria

Answer 40

no

Question 41

mucosa epithelium in stomach, small intestine and large intestine

Answer 41

simple columnar

Question 42

mucosa epithelium in esophagus

Answer 42

stratified squamous

Question 43

mucosa epithelium in rectum

Answer 43

stratified sqamous

Question 44

submucosa in stomach called

Answer 44

rugae

Question 45

small intestine submucosa

Answer 45

all circular folds brunners glands in duodenum

Question 46

what muscle layer is absent in large intestine

Answer 46

submucosa

Question 47

lamina propria in stomach

Answer 47

fundic, cardiac and pyloric glands