Embryology of urogenital system Flashcards
From what tissue layer does the urinary and genital tracts arise?
- intermediate mesoderm
True/ False
The intermediate mesoderm separates the lateral and paraxial mesoderm, and will form to give rise to the urogenital ridge.
true
What are the three phases of kidney development?
- pronephros
- mesonephros
- metanephros
What features best characterize the pronephros time frame?
- regress at 5 weeks
- begins development in cervical region of embryo
- fully contained in embryo; essentially useless for secretion of waste out of embryo
Which features characterize the mesonephros development from 6-10 weeks?
- time functional glomeruli form
- mesonephric tubes form off the mesonephric duct
- mesonephric duct opens into cloaca
- ureteric bud begins formation
What structures are derived from the ureteric bud?
- collecting ducts
- major/minor calyces
- major calyces
- renal pelvis
- ureters
What structures does the mesonephric duct system give rise to?
- ductus deferens
2. vestigial female structures
What features characterize the metanephros phase of development?
- ureteric bud forms the metanephric duct which developems into ureter
- metanephrogenic blastema forms the renal tubules
- glomerulus forms
What is the primary purpose of the metanephros (in utero)?
- provides supplementation to amniotic fluid
2. no filtering; performed by placenta
What is one way that oligohydramnios can occur?
- obstruction to emrbyo urethra
2. kidney agenesis
Renal agenesis can result in both oligohydramnios and fetal compression, what are further effects of both of these symptoms?
- pulmonary hypoplasia
- altered face (deformity)
- club foot, from compression; lack of space
- breech presentation
What is an accessory renal vessel and is it problematic?
- extra vessel that supplies the kidney.
2. only problematic if it enters at upper/lower pole of kidney. Entrance at hilum has no negative effects
What is an aberrant accessory renal vessel?
- vessel that enters kidney at upper/lower poles
What negative side effects can an aberrant renal vessel have?
- obstruct portions of the ureters
- reduce glomerular pressures–> systemic effects
- all vessels arise from abd aorta
What is renal fusion?
- when the kidneys develop, they fuse together preventing their rotation of hilum to midline.
- generally unnoticed
Horseshoe kidneys are best described as what?
- kidneys that fuse into shape of horsehoe.
- generally catch on IMA while rising from the pelvic caivty
- then can receive blood supply from iliac or middle sacral artery
What are commone types of ectopic kidneys?
- horseshoe
2. pelvic kidney
Where will most ectopic kidneys receive blood supply?
- potentially abd aorta, unless trapped in the pelvis.. Then from common iliac artery or middle sacral artery
What is a Wilmer’s Tumor? (this does not refer to the pig in Charlotte’s web; that’s Wilber)
- benign kidney cancer in newborn
2. caused by mutation to WT1 gene
The cloaca separates to form what during urinary bladder development?
- anteriorly: forms bladder and urogenital sinus
2. posteriorly: forms rectum and anal canal
The anterior section of the cloaca further develops to form what structures?
- lower urogenital tract
- prostate and penile urethra
- lower vaginal urethra
What are the borders of the trigone?
- ureters entrance mark the top border
- mesonephric ducts (form ductus deferens in males) mark the inferior most point
- mesonephric migration inferiorly expands the bladder and moves the vas deferens out of the bladder into the urethra for ejaculation
How does the body correct the small size of the bladder, and prevent semen from entering into the urinary bladder?
- the mesonephric ducts migrate inferiorly to the ureters causing the bladder to expand
- mesonephric ducts then insert into the urethra just inferior to the internal urethral sphincter
What must the bladder be continuous with in order to remove urine into the umbilical cord?
- continuous with the allantois which becomes the urachus