Renal Embryo Flashcards
Origin and location of intermediate mesoderm
Part of mesoderm formed during gastrulation
Located between paraxial mesoderm and lateral plate
[Dennis says in the trunk, immediately lateral to each somite]
3 stages of kidney development with timing
Pronephros = early 4th week
Mesonephros = late 4th week
Metanephros = 5th week
The pronephros degenerates by day 24-25, but __________ persist and are used by the mesonephros
Pronephric ducts
Mesonephros develops _____ to pronephros
Caudal
What are the 2 components of the mesonephric kidney and what is the difference in their origin?
Mesonephric ducts
Mesonephric tubules
Both originate from nephrogenic cord/intermediate mesoderm, but ducts develop first then induce tubules to form from surrounding intermediate mesoderm
Mesonephric tubules eventually form the ________ (adult kidney structure)
Renal corpuscles
[medial end is glomerular capsule]
Pronephric ducts run caudally and open into the ______
Cloaca
What is the fate of the mesonephric ducts?
Regress in females
Form efferent ductules in males
The mesonephros functions as the interim kidney from 6-_____ weeks, when it stops functioning. It degenerates by _____ weeks
10; 12
The caudal end of each mesonephric duct induces the _________
Ureteric bud
2 major parts of metanephros
Ureteric bud = outgrowth of mesonephric duct
Metanephric blastema = from nephrogenic cord
The metanephros forms the functional kidney by the _____ week
9-10th
Adult derivatives of ureteric bud
Ureter Renal pelvis Major calyx Minor calyx Collecting duct
Adult derivatives of metanephric blastema
Metanephric mesoderm becomes connecting tubule
Metanephric vesicles become DCT
Inductive influence of the ________ causes the metanephric mesoderm to differentiate into metanephric vesicles, which later give rise to primitive _______ tubules that are critical to nephron formation
Collecting ducts
S-shaped renal
S-shaped renal tubules differentiate into what structures?
Collecting tubule, DCT, LOH, PCT, Bowman’s capsule
When is nephron formation complete
At birth, maturation continues after that
The bladder develops from the vesical part of the urogenital sinus. What are the germ layer contributions?
Endoderm (urogenital sinus) = transitional epithelium
Splanchnic mesoderm = submucosa and muscularis
Intermediate mesoderm (mesonephric ducts) = trigone
The bladder is continuous with the _____ in utero, which is a fetal membrane developed from the hindgut
Allantois
The allantois eventually constricts and forms the ________ which extends from the apex of the bladder to the umbilicus, and will eventually form the _______ ligament
Urachus
Median umbilical
Derivatives of vesical part, pelvic part, and phallic part of urogenital sinus
Vesical part forms most of urinary bladder
Pelvic part forms neck of bladder, prostatic urethra (m), and urethra (f)
Phallic part forms spongy urethra (m) and lining of vaginal vestibule (f)
______ = condition characterized by urethral opening on dorsum of genital tubercle rather than ventral
This commonly occurs with what other condition
Epispadias
Occurs with exstrophy of bladder
Origin of the components of the suprarenal gland
Capsule = mesonephric mesoderm
Cortex = coelomic epithelium (somatic mesoderm)
Medulla = NCCs
What is the likely embryological issue resulting in unilateral renal agenesis?
Defect in reciprocal induction between ureteric bud and metanephric blastema
Bilateral renal agenesis is associated with amniotic fluid issue known as ________, and is also commonly comorbid with ______ syndrome
Oligohydramnios; potter
Renal duplications result from abnormal divisions of _________
Ureteric bud
[can be incomplete with divided kidney+bifid ureter or complete with double kidney and bifid or separate ureters]
What condition is characterized by fusion of the kidneys at inferior poles? What causes them to sit lower in abdominal cavity?
Horseshoe kidney, sit lower bc their ascent is prevented by inferior mesenteric artery
Accessory renal vessels are relatively common with adult kidneys, why are these potentially problematic?
Can obstruct ureter, causing enlarged renal pelvis and hydronephrosis
They are end arteries, so if they’re damaged can lead to ischemia
What are the 3 potential urachal anomalies?
Urachal cysts = remnants of epithelial lining of the urachus that can become infected and enlarged
Urachal sinus = end of urachus remains open into bladder (inferior region) or umbilicus (superior region)
Urachal fistula = entire urachus remains patent
When does the metanephros become functional?
A. At week 3 B. At week 4 C. At week 10 D. Just before birth E. Just after birth
C. At week 10
A urachal cyst is a remnant of the:
A. Urogenital sinus B. Urogenital ridge C. Cloaca D. Allantois E. Mesonephric duct
D. Allantois
During surgery for a benign cyst on the kidney, the surgeon notes that the patient’s right kidney has 2 ureters and 2 renal pelves. This malformation is:
A. An abnormal division of the pronephros
B. An abnormal division of the mesonephros
C. Formation of an extra mass of intermediate mesoderm
D. A premature division of the metanephric blastema
E. A premature division of the ureteric bud
E. A premature division of the ureteric bud
The transitional epithelium lining the urinary bladder is derived from:
A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells
B. Endoderm
The transitional epithelium lining the ureter is derived from:
A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells
C. Mesoderm
The podocytes of Bowman’s capsule are derived from:
A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells
C. Mesoderm
The proximal convoluted tubules of the definitive adult kidney are derived from:
A. Ureteric bud B. Metanephric vesicle C. Mesonephric duct D. Mesonephric tubules E. Pronephric tubules
B. Metanephric vesicle
The trigone on the posterior wall of the urinary bladder is formed by the:
A. Incorporation of the lower end of the mesonephric ducts
B. Incorporation of the lower end of the pronephric ducts
C. Incorporation of the metanephric blastema
D. Incorporation of the mesonephric tubules
E. Incorporation of the pronephric tubules
A. Incorporation of the lower end of the mesonephric ducts
A 6 year old girl presents with a large abdominal mass just superior to the pubic symphysis. The mass is tender when palpated and fixed in location. During surgery, a fluid-filled mass is noted connected to the umbilicus superiorly and to the urinary bladder inferiorly. What is the diagnosis?
A. Pelvic kidney B. Horseshoe kidney C. Polycystic disease of the kidney D. Urachal cyst E. Exstrophy of the bladder
D. Urachal cyst
Immediately after birth of a boy, a moist, red protrusion of tissue is noted just superior to his pubic symphysis. After observation, urine drainage is noted from the upper lateral corners of this tissue mass. What is the diagnosis?
A. Pelvic kidney B. Horseshoe kidney C. Polycystic disease of the kidney D. Urachal cyst E. Exstrophy of the bladder
E. Exstrophy of the bladder
