GI and Respiratory System Development Flashcards
what is the only nervous system that can work without the brain and spinal cord
enteric
where does enteric nervous system originate from?
neural crest cell
where does notocord come from
mesoderm cells
what is the very first part of mesoderm
periaxialmesoderm
lateral plate mesoderm will be split into what two parts
parietal and visceral
what does endoderm form
inner epithelial lining of gut tube
gut tube is form from what
endoderm inside
visceral lateral plate mesoderm outside
oropharingeal membrane is also called what
buccopharyngeal membrane
what is the buccopharyngeal memebrane
separates mouth from pharynx
is mouth part of GI tract embryolically, why
NO - has skeletal muscle
GIT is divided into what 4 parts
pharyngeal foregut
foregut proper
midgut
hindgut
lung wall is formed from what
visceral lateral plate mesoderm (buds off of GI)
what forms from pharyngeal foregut
epithelial lining of pharynx, larynx, lungs
what forms from foregut proper
epithelial lining of esophagus, stomach, liver, pancreas, first half of 2nd part of duodenum
does the kidney bud off of GI tract?
No
What forms from midgut
lining of rest of duodenum jejunum ileum cecum asc. colon proximal 2/3 of transverse colon
what forms from hindgut
distal 1/3 of transverse colon desc. colon bladder rectum upper 1/3 of anal canal
where does hindgut end?
the cloaca
dendate or pectinate line
after the pecinate line what is it called
proctoderm
the gut wall is formed from what
visceral lateral plate mesoderm
blood vessels from visceral lateral plate mesoderm forms what
entire cardiovascular system
what does the endoderm form?
all the inner lining of entire GI system + anything that buds off of it
what is esophageal atresia
esophagus ends as a blind sac
what causes esophageal atresia
improper esophageal recanlization
defective tracheosophageal septum
non vascularization of esophagus
what is tracheosophgeal fistula
improper connection of esophagus to trachea
what does tracheosophgeal fistula usually result in
polyhydraminos
what is the major mover of the development of the foregut
stomach
which side develops more quickly in foregut
back develops more quickly, causing 90 degree rotation
what does the 90 degree rotation of stomach do
everything connected to stomach will also be moved
the cardio region of stomach moves in which direction after 90 degree rotation
moves down
what direction does pyloris move after 90 degree rotatoin fo stomach
up
where is liver being forced to when the stomach rotates 90 degrees
to the right
what is congenital hypertrophic pyloric stenosis
increase size (>2X) of the circular muscles of the pyloric sphincter resulting in poor or non passing of food to the duodenum resulting in projectile vomiting of food without bile
what happens to duodenum when stomach undergoes 90 degree turn
rotate and become retroperitoneal
describe how duodenum progress with its hollow/solid phases
starts hollow, then solid, then hollow
what is duodenal atresia?
Normal duodenum’s lumen becomes filled in (5th / 6th week) but recanalizes by 8th week (like esophagus)
-If not recanalized shows up as double bubble sign (duodenum is blocked causing a distended gas filled stomach and duodenum causing projectile vomiting with bile as bile duct normally enters proximal to obstruction
anything attaching to the liver to the stomach, what happens when stomach is rotated
it also rotates
ventral mesentary only develops where
foregut
what does hepatic divertuculum form?
ventral pancreas, hepatopancreatic, hepatic and bile ducts and gallbladder with the same endothelial lining
as the pancreas goes to the back what does it pull with it
bile duct, common hepatic duct
what happens to ventral pancreas
it fuses with dorsal pancreas
ventral pancreatic bud fuses with what
dorsal pancreatic bud
what form the walls of the pancreas
visceral lateral plate mesoderm
main pancreatic duct merges with what
bile duct
physiological umbiicatl herniation is normal due to what
growth of kidney and liver
rostral limb is superior to what
SMA
herniated midgut loop undergoes initial rotation around what
SMA
what is total of rotations that midgut does
270degrees
where does the hindgut end embryologically
cloical membrane
upper part of anal canal develops from what
endodermal cloaca & lower part of ectoderm
anal membrane ruptures in what week, and what is significance
9th week
in adult this represents pecinate line
the internal laryngotracheal groove in larynx forms what
laryngotracheal diverticulum
the laryngotracheal diverticulum forms what
tracheobronchial diverticulum
what does tracheobronchial diverticulum divide into
lung buds & bronchial buds
rostral part of tracheobronchial diverticulum is surrounded by what?
pharyngeal arches
what is stage 1 of the development and maturation of lung
Pseudoglandular period
what weeks is the Pseudoglandular period ?
5-16 weeks
terminal bronchioles have no what
respiratory bronchiales
alveoli
What is stage 2 of the development and maturation fo lung
Canalicular period
what weeks is the Canalicular period ?
16-26 weeks
what week have respiratory bronchioles develop, and respiration is possible?
24
how many mature alveoli develop after birth
90-95%
