Development Of Renal System Flashcards
Where does the renal and genital system develop from
Intermediate mesoderm (between paraxial and lateral plate)
What is the intermediate mesoderm
Ridge of tissue on the posterior abdominal wall
What is the cloaca
Common cavity for urogenital and digestive systems
What is the allantois
An extension of the cloaca into the umbilicus
What 2 things does the urorectal septum divide the cloaca into
Urogenital sinus
Anal canal
What are the 3 parts of the urogenital sinus and what do they develop into
Upper - bladder
Middle - prostate and membranous urethra in males
Lower - phallic part (differs between male and female)
What happens when the allantois obliterates
Remnant is the urachus which connects the bladder to the umbilicus
What are the 3 overlapping kidney systems formed in a cranial to caudal sequence
Pronephros
Mesonephros
Metanephros
What is the pronephros
Originates in the cervical and develops in week 4
Disappears by week 5
It is non functional
What is the origin of the mesonephros
Thoracic and lumbar intermediate mesoderm
What does the mesonephros consist of
Consists of a ridge of tissue and the mesonephric duct
What happens to tubules and mesonephric duct in females
They degenerate
What do the excretory tubules and capillaries give rise to
Tubules - bowman’s capsule
Capillaries - glomerulus
What happens to the tubules and mesonephric duct in males
A few remain and form part of the genital system
Mesonephric duct - vas deferens
Tubules - efferent ducts of testis
Where does the metanephros develop
Definite kidney develops in the Pelvic region
What’s the relationship between the development of the collecting and excretory system
Develop differently but are Dependent on each other for development
When does the kidney start to function
Week 12 of gestation
Where does the collecting system develop from
Outgrowth from the mesonephric duct called the ureteric bud
What covers the ureteric bud
Cap of metanephric tissue
What gives rise to the renal pelvis and major calyces
Renal pelvis - ureteric bud grows into the cap of metanephric tissue
Major calyces - when above splits into 2 (ie further branching)
In the excretory system, how are glomeruli formed
Metanephric tissue forms renal vesicles
Vesicles become tubular and capillaries develop at one end - glomerulus
What drives development of the excretory system
Interaction between the epithelium of the uterus bud and metanephric tissue
Factors produced by metanephric tissue induce ureteric bud to branch
Factors produced by the bud promote continued growth of the metanephric tissue
What happens during the ascent of kidneys in utero
Ascend from pelvis to abdomen and body grows
New vessels derived from more proximal parts of the aorta and lower vessels regress
Where is urine excrete in the fetus
Into the amniotic fluid which is swallowed by the fetus
