Basic emryology Flashcards
Separation into pleura and pericardinal cavities
pleuropericardial folds (mesoderm) appear in between developing lungs and heart grow from lateral body wall towards midline to separate pericardial cavity (ventrally) from pleural cavity (dorsally)
what forms the lower arm of the umbilical herniaton
terminal ileum, cecum, appendix, colon
canalicular period
16-26 weeks Respiratory bronchiles and some alveolar ducts start to appear (terminal sacs start to form, but not enough or mature enough). some vascularization starts to appear, but premature is infants have poor prognosis
what is the trachea made out of?
epithelium and glands are endoderm smooth muscle, connective tissue, cartilage come from splanchnic lateral plate mesoderm
Congenital diaphragmatic hernia
incomplete closure of pericardioperitoneal canals
Mesenery
formed by splanchinic mesoderm around gut tube
Liver formation
Through a hepatic diverticulum that grows in the ventral mesentery
vitelline duct
the connection to the yolk sac in the midgut to the ileum
Bild Duct
grows in ventral mesentery and rotates left 270° to enter duodenum from posterior left and fuse with pancreatic duct
ventral mesentery of liver becomes..
falciform ligmanet
mesentery between stomach and liver become…
lesser omentum This is derived from spetum trasnversum
Urethral plate in the males
is inclosed inside and reaches tip of penis by ectodermal thickening
What forms glans of clitoris?
slight elongation of genital tubercle
Genital ducts
mesonephric ( wolffian) paramesonephric ducts (mullarian)
female reproductive tract
no SRY develops ovary into Follicular cells and stromal cells no TDF means no testosterone and the mesonephric ducts regress and paramesonephric ducts persists.
how long until external genetalia are indistinguishable
week 12
urogential sinus of female
bladder, urethra, lower 2/3 of vagina, bulbourethral glands, vestibule,
Physiological herniation
when the elongation of the mid gut tube is too rapid for the growth of the body cavity and herniates out of the umbilical cord.
urogenital sinus creates…
bladder, urethra, vagina, prostate gland, and prostatic and membranous urethras in males
Foramen ovale
shunt between right and left atria
metanephric blastema produces…
formation of nephrons bowman’s capsule, convuluted tubes, loop of henle
what forms vestibule
urogential plate
paramesoneprhic ducts give rise to..
uterus, uterine tubes, upper 1/3 or vagina
allantois
membranous sac taht communicates from the urogenital sinus (and eventually bladder) to umbillicus. Forms the urachus after birth.
Septum transversum
during crano-caudal folding forms the central tendon of the diaphragm between heart and future liver. It is formed higher and descends and on the way recieves myoblasts that from the skeletal muscles of the diaphram (C3-5 with the phrenic n).
Hindgut derivatives
distal 1/3 transverse colon descending colon sigmoid colon rectum upper anal canal urogential sinus
what does the mesonephric ducts form…
epididymis and ductus deferns (rete testes, efferent ducts, seminal vesicle, trigone)
endocardial tube
vasculogenic cell clusters that line the horseshoe area above oropharyngeal membrane in splanchinic mesoderm.
renognesis
reciprocal induction of metanephric blastema and uteric bud to grow.
in male the gland of penis is formed by…
Grow of the genital tubercle
secondarily retroperitoneal viscera
pancrease dudodeum asc. colon desc. colon
In males, the scrotum is formed by…
swelling of the labioscrotal folds. their fusion forms the scrotal raphe
tracheoesophageal tube
divides the foregut ventrally into trachea (and lung buds) and dorsally into esophagus
Derivatives of midgut
Lower duodenum jejunum ileum cecum appendix ascending colon prox 2/3 or transverse colon