week 2, lecture 1 Flashcards
3 cavities service from the intra-embryonic coelom
pericardial cavity
pleural cavity
peritoneal cavity
structure that gives rise to the wall of the gut (body wall)
splanchnopleure
slide 8 review
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structure that forms the embryonic gut
splanchnopleure
what type of folding forms the body wall
lateral folding (horizontal)
what type of folding forms the brain vesicles and somites
cranial caudal or cephalo caudal folding (medial) [head to tail]
where is the foregut and what separates it from the mouth (stomodeum)
foregut is between the brain and heart
Oropharyngeal membrane separates the the foregut from the stomodeum
(primordium of the mouth)
where does the septum transverse lie and what does it develop into (and separates)
its caudal (below) the heart
Develops into the central tendon of the diaphragm and separates the abdominal cavity from the thoracic cavity
what does the septum transverse develop into
central tendon of the diaphragm
where does the caudal eminence project over to create the future site of the anut
cloacal membrane
what becomes the hindgut (the same structure also becomes the midgut)
part of the endodermal germ layer
what happens in caudal folding
Theconnectingstalk(primordiumoftheumbilicalcord)isnowattachedtothe ventral surface of the embryo, and the allantois is partially incorporated into the embryo
what structure causes lateral folding
rapidly growing spinal cord and somites
during lateral folding what duct is formed to lessen the connection between the midgut and umbilical vessel
omphaloenteric (vitelline) duct
what is the amnion narrowed to in lateral folding
umbilical region
what region of the ventral body wall stays open
connecting stalk
what duct of the gut tube that connects the midgut to the yolk Salk is open?
vitelline duct
(eventually degenerates)
what does the parietal layer of the lateral plate mesoderm form?
forms the parietal layer of the serous membranes lining outside of the peritoneal, pleural, & pericardial cavities.
what does the visceral layer of the lateral plate mesoderm form?
formsthe visceral layerofthe serous membranes lining outside of the abdominal organs, lungs, and heart.
how are the visceral and parietal layers continuous with each other
Visceral&parietal layers are continuous with each other as the dorsal mesentery.
▪ Extends from the posterior body wall to the gut tube.
where is the ventral mesentery and where does it extend to and what does it create
Ventral mesentery exists from the caudal foregut to the upper portion of the
duodenum.
▪ Extends from the anterior body wall to the gut tube
▪ Results from the thinning of the mesoderm of the septum transversum.
what is the septum transverse
Thick mesodermal tissue between the thoracic cavity & stalk of the yolk sac.
This septum does not separate the thoracic and abdominal cavities, but leaves large openings, the pericardioperitoneal canals, on each side of the foregut.
what is the septum transverse derived from
Derived from the visceral (splanchnic) mesoderm surrounding the heart and assumes its position between the primitive thoracic and abdominal cavities when the cranial end of the embryo grows and curves into the fetal position
how does the diaphragm develop
pleuroperitoneal folds fuse with mesentery of esophagus to form crura of diaphragm
pleuroperitoneal membranes then grow and fuse to cover septum transverse and form central tendon on diaphragm
diaphragm is derived from
2 pleuroperitoneal
membranes
Muscular components
from somites
at C3-C5
Mesentery of the
esophagus
fistula define
A fistula is an abnormal connection between two body parts, such as an organ or blood vessel and another structure
atresia define
Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent
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