Embryology Of Foregut Flashcards
endodermal germ layer.
This germ layer covers the (ventral or Dorsal?) surface of the embryo and forms the (roof or floor?) of the yolk sac.
With development and growth of the brain vesicles, the embryonic disc begins to fold ________________. The folding is most pronounced in the regions of the ____ and _____, where they form head and tail fold
Ventral
Roof
cephalocaudally
head and tail
In the anterior part, the endoderm forms the _______; in the tail region, it forms the _______.
foregut
hindgut
The part between foregut and hindgut is the ______.
midgut
The midgut temporarily communicates with the yolk sac by way of a (broad or narrow?)?stalk, the _____
•At its cephalic end, the foregut is temporarily bounded by an ectodermal-endodermal membrane called the ________
Broad
vitelline duct
buccopharyngeal membrane.
In the ___ week, the buccopharyngeal membrane ruptures, establishing an open connection between the _____ and the primitive gut
•The hindgut also terminates temporarily at an ______________ membrane- the ____ membrane, which breaks down in the ___ week to create the opening for the ____.
4th
amniotic cavity
ectodermal-endodermal
cloacal
7th
anus
Extent of Foregut:
•Foregut starts from the Oral cavity and terminates at the level of ________
Ampulla of Vater
By the end of the first month: The \_\_\_\_\_\_\_ is visible, \_\_\_\_\_\_\_\_ has begun to bud Connection of the midgut to the yolk sac is \_\_\_\_\_\_\_\_\_ to a \_\_\_\_\_\_
stomach bulge
Dorsal pancreas
reduced to a yolk stalk
A respiratory diverticulum develops from the (roof or floor?) of the foregut, divides the foregut into two parts:
•Part cranial to diverticulum - ______
•Part caudal to diverticulum -_______
Floor
primitive pharynx
foregut proper
The foregut derivatives except the _______, ___________ and most of ______ are supplied by the _________- the artery of the foregut
pharynx
lower respiratory tract
esophagus
Celiac trunk
Development of the Esophagus
•Esophagus develops from the foregut immediately (cranial or caudal?) to the primitive pharynx
The _________________ separates it from the developing trachea
Caudal
tracheo-esophageal septum
Initially (short or long?) in length, esophagus elongates (slowly or rapidly?) due to growth and _____ of ____ and ____
•Reaches its final relative length by ___ week
Short
Rapidly
descent of heart and lungs
7th
The epithelial cells of the esophagus proliferate and obliterate the lumen (partly or completely) but temporarily
Recanalization normally occurs by ____________ period (___ wk)
Failure of proper recanalization leads to ________ of the ______ (stenosis)
the end of the embryonic
8th
narrowing of the lumen
Esophagus
Epithelium & glands:
•Derived from ___derm
Striated muscles (mainly in the superior third): •Derived from the \_\_\_\_\_\_ in the \_\_\_\_\_\_
Smooth muscles (mainly in the inferior third): •Derived from the surrounding \_\_\_\_\_\_\_\_
endo
Mesenchyme ; caudal pharyngeal aches
splanchnic mesoderm
Congenital malformations of Esophagus
•Errors in forming the esophagotracheal septa and/or re-canalization lead to __________ and/or ____________, respectively.
Re-canalization –errors in this process lead to esophageal _______
tracheoesophageal fistulas
esophageal atresia
stenosis
Atresia of Esophagus prevents the normal passage of amniotic fluid into the ______ leading to the accumulation of excess fluid in the amniotic sac (_________)
Short esophagus resulting in _______
intestinal tract
Polyhydroamnios
hiatal hernia
Development of the Stomach
•In the middle of the ____ week, a ___________ appears in the (cranial or caudal?) part of the foregut (indicating site of future stomach)
•This dilatation (oriented in the midline), enlarges and broadens _____
4th
fusiform dilatation
Caudal
ventral dorsally
Stomach
During next 2 weeks:
•The ______ border grows much faster and forms the _____ curvature
•The ___ border forms the ____ curvature
dorsal
greater
ventral
lesser
As stomach enlarges, it slowly rotates ___ degrees, ___wise around its _________ axis
90
clock
Longitudinal
As a result of the stomach’s rotation,
- The ventral border moves to the ___ and the dorsal border to the ____
- The original left side becomes the ______ surface and the original right side becomes the ______ surface
right
left
ventral
dorsal
Initially the two ends of the stomach lie in the midline. During rotation:
•the cranial end moves to the ___ and slightly ____
•the caudal end moves to the ____ and _____
left; inferiorly
right; superiorly
Formation of the Lesser sac/Omental Bursa
•During its dev, the stomach is suspended in the midline with the help of ____-layered mesenteries (_______),
double
mesogastrium
The Dorsal mesogastrium connects stomach to the _____ body wall.
•The Ventral mesogastrium attaches the gut tube to the _____ abdominal wall
•Rotation around the longitudinal axis pulls the ‘dorsal mesogastrium’ to the ____.
•This move leads to the formation of _______
post/dorsal
ant
left
OMENTAL bursa
Formation of Greater & Lesser Omenta
•With the rotation of stomach, the ____ curvature along with the attached ___ mesogastrium becomes the ‘Greater Omentum’
•While the _____ mesogastrium lying between the _____ curvature of stomach & the (superior or inferior?) surface of liver- ‘Lesser Omentum’
greater; dorsal
ventral; lesser; inferior
Stomach Abnormalities
- Pyloric stenosis occurs when ____ of the stomach in the region of the pylorus _______.
- There is an extreme _____ of the pyloric lumen, passage of food is obstructed- severe vomiting.
musculature; hypertrophies
narrowing