abdominal cavity I- embryology Flashcards
(39 cards)
ectoderm
forms integument (skin) and nervous system (dorsal hollow nerve and chord, eventually spinal cord and all nerves and the lining of the anus (proctodeum) and mouth (stomodeum)
Mesoderm
forms muscles, muscular walls of gut tube and most of connective tissues including bones
endoderm
the lining of the gut and most gut derived organs
yolk sac
sac attached to the primitive endodermal gut tube connected to the yolk sac via the omphaloenteric duct or yolk stalk
why is the developing fetus not effected by alcohol in the first four weeks of development?
because it is getting all of its nutrients from the yolk sac that is attached to the primitive endoderm via the yolk stalk or omphaloenteric duct (future umbilical cord)
ie: the baby is not attached to the mom’s body yet
what does the yolk sack do?
- gives nutrients
- forms endoderm that forms the respiratory tract and the gut tubes
- germ cells and yolk stalk gives rise to the gonads
- blood develops here until liver is fxnl
Foregut
what is it?
arterial supply?
gives rise to?
-an embryonic gut division
-area includes stomodeum (primitive mouth) to first 1/3 of duodenum
-oropharyngeal membrane separates the stomodeum from the foregut
arterial supply- celiac trunk
-gives rise to-pharyngeal pouches
midgut
what is it?
arterial supply?
gives rise to?
what is it?-the lower 2/3 of duodenum to the upper 2/3 of the colon
arterial supply? superior mesenteric
gives rise to? the yolk stalk
hindgut
what is it?
arterial supply?
gives rise to?
what is it? last 1/3 of the colon to the proctodeum
arterial supply? inferior mesenteric a
gives rise to? gives rise to the alanosis
recanalization
what is it and what are errors called?
- hollowing out the primitive gut tube
- atresia- no opening
- stenosis-narrowing of gut tube
what’s a mesentery?
- a double layer of peritoneum (mesoderm) formed by splanchnic mesoderm that connects organs to the body wall
- aka form fibrous sheets around organs
- 2 types- parietal peritoneum and visceral peritoneum
in a developing embryo what becomes of the ventral mesentery?
-ventral- disintegrates and turns into the
A) falciform ligament (liver to ventral body wall) -therefore attached
B) coronary ligament- (liver to diaphragm) -therefore attached
c) lesser omentum (liver to stomach to duodenum) -just covered
in a developing embryo what becomes of the dorsal mesentery?
-Dorsal- proliferates and covers most of our organs
what is the difference between the parietal and visceral mesentary
parietal- around the body cavity
visceral -around the viscera (organs)
intraperitoneal, primary retroperitoneal, secondary retroperitoneal
- intraperitoneal- organ suspended in mesentery (within the peritoneal cavity)-always-stomach, spleen and transverse colon
- primary retroperitoneal- always in the retroperitoneal space- esophagus and rectum)
- secondary retroperitoneal- organs developed in the mesentery (in the peritoneum) but due to rotation during development now are behind the mesenary in the retroperitoneal space- (distal 2/3 of duodenum and asc/dec colon)
what are these organs- primary retroperitoneal, secondary retroperitoneal or intraperitoneal: spleen distal 2/3 of duodenum aorta and vena cava pancreas colon-asc and dec transverse colon kidneys stomach esophagus rectum gall baldder and bile duct
- spleen- intraperitoneal
-distal 2/3 of duodenum: secondary peritoneum - aorta and vena cava- primary peritoneum
-pancreas-secondary
-colon-asc and dec-secondary
-transverse colon-intraperitoneal
-kidneys-primary
-stomach- intraperitoneal
-esophagus- primary
-rectum-primary
gall bladder and bile duct-intra
what organs are included in the foregut
pharnx
esophagus
stomach
proximal 1/3 of duodenum
what outpockets are developed from the foregut
pharyngeal pouches, lower respiratory system, liver, pancreas and gallbladder
how is the esophagus formed and what are 2 potential problems?
- the esophagus is formed by one tube that the trachea also forms from.
- they are separated by the tracheoesophageal fold
- probs-
- > atresia of esophagus causes no food to pass thru esophagus
- > fistula opening between the esophagus and trachea where consumed food actually goes to lungs
How can you tell a baby has an esophageal atresia?
POLYHYDRAMIOS
- when babies are developing they pee via the alanosis to form amniotic fluid
- to prevent overfilling of sac, babies drink their own pee
- if there is an atresia, there is an increased amount of amniotic fluid
what causes the greater and lesser curvatures of the stomach?
the dorsal border of the stomach growing faster than the ventral portion of the stomach
dorsal =greater curvature
ventral =lesser
how does the stomach rotate during development and where do the lesser and greater curvatures end up because of this?
- turns 90 degrees
- lesser curvature (ventral side) moves to right
- greater curvature (dorsal)- left
where does the right vagus go on the stomach? left?
- Right vagus- greater curvature (dorsal surface)
- Left vagus- lesser curvature (ventral surface)
what is formed by ventral outgrowths of the duodenum
liver, pancreas and gall bladder (makes sense since they have contents that empty into it)
