Development Of Hind Gut Flashcards
The cecum and appendix develop from _______
cecal bud
cecal bud
a _______ shaped (constriction or dilatation?) that appears in the _____ segment of the midgut loop near its (apex or base ?)
conical; dilatation
postarterial
Apex
Apex of midgut loop
site of attachment of ????
vitelline duct
The proximal part of the cecal bud grows (slowly or rapidly?) and forms _____, while its distal part remains (wide or narrow?) to form the _____.
cecum
Narrow
appendix
Change in Shape of Cecum and Appendix
At birth, the cecum is ____ in shape and vermiform appendix is attached at its (apex or base?) .
Later cecal growth results in formation of __________—one on either side.
conical
Apex
two saccules
The (right or left?) saccule grows faster than the (right or left?) .
As a result, the apex of the cecum and the base of the appendix is pushed towards (left or right?) , nearer to _____ junction.
For this reason in adults, the base of the appendix is attached to (anterior or posterior?) (medial or lateral?) wall of the cecum, near the ileocecal junction.
right; left
Left
ileocecal
Posterior; medial
On the basis of shape of the cecum and site of attachment of appendix, the cecum is classified into following four types :
- ____ (____) type
- ____ (_____) type
- _____ type
- ______ type
Conical; fetal
Infantile; quadrate
Normal
Exaggerated
- Conical (fetal) type ( ___ %)
- Infantile (quadrate) type (__%)
- Normal type (_____ %)
- Exaggerated type (___%).
2
3
80–90
4–5
Development of transverse colon
The right two-third of transverse colon develops from the _____ segment of the _____ while the left one-third of transverse colon develops from the _____.
For this reason, the right two-third of transverse colon is supplied by _______ artery and left one-third of transverse colon is supplied by the ________ artery
postarterial; midgut loop
hindgut
superior mesenteric
inferior mesenteric
Development of Descending Colon
It develops from _____.
hindgut
Development of Sigmoid Colon
It also develops from ____.
hindgut
Development of Rectum
The terminal dilated part of the hindgut distal to ____ is called _____.
allantois
cloaca
Cloaca is divided into two parts by _________
urorectal septum
Cloaca is divided into two parts by urorectal septum:
a) a (broad or narrow?) ventral part called ________
B) a (broad or narrow?) dorsal part is called ______.
Broad; primitive urogenital sinus
Narrow ; primitive rectum
The urogenital sinus gives rise to the ________ and _____ , while the primitive rectum gives rise to the _____ and ____ part of the _______
urinary bladder and urethra
rectum
upper; anal canal
Development of Anal Canal
The anal canal develops from two sources:
a)_____ and (b)______ .
hindgut
proctodeum
The upper half of the anal canal is ___dermal in origin and develops from _________
Endo
primitive rectum.
The lower half of the anal canal is ____dermal in origin and develops from anal pit called _____.
Ecto
proctodeum
Initially, the upper and lower parts of the anal canal are separated from each other by _______.
Later when this membrane ruptures , the two parts communicate with each other.
anal membrane
The site of anal membrane is represented by _____ in adults.
pectinate line
____________ aka Hirschsprung’s disease
Congenital megacolon
Congenital megacolon (Hirschsprung’s disease:
In this anomaly, a segment of the colon is (dilated or constricted?) .
However, it is the segment ______ to _____ that is abnormal.
In this abnormal segment, autonomic ______ ganglia are absent in the _____ plexus.
As a result there is no ___ in this segment.
It occurs 1 in ____ newborns.
This anomaly is produced due to failure of _______________ in the wall of the affected segment of the colon.
This anomaly is commonly seen in the ______ or _____.
Clinically it presents as: (a) loss of ____, (b) ____ retention, and (c) abdominal _____.
Dilated
distal to dilatation
parasympathetic; myenteric
peristalsis ; 5000
migration of neural crest cells
sigmoid colon or rectum
peristalsis; fecal; distension
The newborns with aganglionic congenital megacolon may fail to pass ______ in _______ after birth.
meconium
first 24–48 hours
Imperforate anus:
It is a clinical condition in which the _______ fails to ____ with ____.
The various types of imperforated ani are:
(a)The rectum and anal canal develop normally but _____ fails to ____. This is a (minor or major?) form of imperforated anus and can be corrected by _____ of the _____.
The upper and lower parts of the anal canal remain separated by a ____.
lower part of gut (GIT)
communicate
Exterior
anal membrane; breakdown; minor
excision; anal membrane
gap
