Urinary Embryology Flashcards
What are the three parts of the urogenital sinus?
Vesicle part
Pelvic (middle) part
Phallic part
What does the vesicle part of the urogenital sinus form?
Urinary bladder
What does the pelvic (middle) part of the urogenital sinus form?
Bladder neck and prostatic urethra in male
Entire urethra in female
What does the phallic part of the urogenital sinus form?
Penile urethra
What is formed by the mesonephric ducts incorporating into the posterior bladder wall?
Trigone of the bladder
What is the distal male urethra derived from?
Ectodermal cord
What embryonic tissue makes up the connective tissue and smooth muscle of the urinary bladder and urethra?
Splanchnic mesenchyme
What developmental abnormality can result from partial failure of epithelial cell degeneration in the urachus?
Urachal cyst
What developmental abnormality can result from failure of the umbilical urachus to close?
Urachal sinus
What developmental abnormality can result from a complete failure of the urachal duct to close?
Urachal fistula
What developmental abnormality can result from failure of mesenchymal cells migrating between ectoderm and cloaca?
Exstrophy of the bladder
What developmental abnormality can result from presence of posterior urethral valves in the bladder?
Megacystis or megalocystis
Who is megacystis most common in?
ONLY present in males
Where is the urethral valve present in a case of megacystis?
Where ejaculatory ducts enter prostatic urethra
What gives rise to the adrenocortical primordia?
Cranial part of urogenital ridge
What gives rise to the adrenal medulla?
Neural crest cells
What gives rise to the adrenal cortex?
Adrenocortical primordia (from cranial part of urogenital ridge)
What tissue makes up the fetal adrenal cortex?
Mesoderm
What part of adrenal tissue is very large in a neonate?
Cortex
What eventually replaces the fetal cortex?
Mesenchymal cells
What is defective in adrenogenital syndrome?
21-hydroxylase (Cytochrome P450-C21)
What is overproduced in adrenogenital syndrome?
Androgens
ACTH
What happens in female sexual organ development due to adrenogenital syndrome?
Masculinization of external genitalia
What happens to both males and females in childhood with adrenogenital syndrome?
EARLY rapid growth and skeletal muscle maturation
