Renal Embryo

Question 1

Origin and location of intermediate mesoderm

Answer 1

Part of mesoderm formed during gastrulation

Located between paraxial mesoderm and lateral plate

[Dennis says in the trunk, immediately lateral to each somite]

Question 2

3 stages of kidney development with timing

Answer 2

Pronephros = early 4th week

Mesonephros = late 4th week

Metanephros = 5th week

Question 3

The pronephros degenerates by day 24-25, but __________ persist and are used by the mesonephros

Answer 3

Pronephric ducts

Question 4

Mesonephros develops _____ to pronephros

Answer 4

Caudal

Question 5

What are the 2 components of the mesonephric kidney and what is the difference in their origin?

Answer 5

Mesonephric ducts
Mesonephric tubules

Both originate from nephrogenic cord/intermediate mesoderm, but ducts develop first then induce tubules to form from surrounding intermediate mesoderm

Question 6

Mesonephric tubules eventually form the ________ (adult kidney structure)

Answer 6

Renal corpuscles

[medial end is glomerular capsule]

Question 7

Pronephric ducts run caudally and open into the ______

Answer 7

Cloaca

Question 8

What is the fate of the mesonephric ducts?

Answer 8

Regress in females

Form efferent ductules in males

Question 9

The mesonephros functions as the interim kidney from 6-_____ weeks, when it stops functioning. It degenerates by _____ weeks

Answer 9

10; 12

Question 10

The caudal end of each mesonephric duct induces the _________

Answer 10

Ureteric bud

Question 11

2 major parts of metanephros

Answer 11

Ureteric bud = outgrowth of mesonephric duct

Metanephric blastema = from nephrogenic cord

Question 12

The metanephros forms the functional kidney by the _____ week

Answer 12

9-10th

Question 13

Adult derivatives of ureteric bud

Answer 13

Ureter
Renal pelvis
Major calyx
Minor calyx
Collecting duct

Question 14

Adult derivatives of metanephric blastema

Answer 14

Metanephric mesoderm becomes connecting tubule

Metanephric vesicles become DCT

Question 15

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

Answer 15

Collecting ducts

S-shaped renal

Question 16

S-shaped renal tubules differentiate into what structures?

Answer 16

Collecting tubule, DCT, LOH, PCT, Bowman’s capsule

Question 17

When is nephron formation complete

Answer 17

At birth, maturation continues after that

Question 18

The bladder develops from the vesical part of the urogenital sinus. What are the germ layer contributions?

Answer 18

Endoderm (urogenital sinus) = transitional epithelium

Splanchnic mesoderm = submucosa and muscularis

Intermediate mesoderm (mesonephric ducts) = trigone

Question 19

The bladder is continuous with the _____ in utero, which is a fetal membrane developed from the hindgut

Answer 19

Allantois

Question 20

The allantois eventually constricts and forms the ________ which extends from the apex of the bladder to the umbilicus, and will eventually form the _______ ligament

Answer 20

Urachus

Median umbilical

Question 21

Derivatives of vesical part, pelvic part, and phallic part of urogenital sinus

Answer 21

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)

Question 22

______ = condition characterized by urethral opening on dorsum of genital tubercle rather than ventral

This commonly occurs with what other condition

Answer 22

Epispadias

Occurs with exstrophy of bladder

Question 23

Origin of the components of the suprarenal gland

Answer 23

Capsule = mesonephric mesoderm

Cortex = coelomic epithelium (somatic mesoderm)

Medulla = NCCs

Question 24

What is the likely embryological issue resulting in unilateral renal agenesis?

Answer 24

Defect in reciprocal induction between ureteric bud and metanephric blastema

Question 25

Bilateral renal agenesis is associated with amniotic fluid issue known as ________, and is also commonly comorbid with ______ syndrome

Answer 25

Oligohydramnios; potter

Question 26

Renal duplications result from abnormal divisions of _________

Answer 26

Ureteric bud [can be incomplete with divided kidney+bifid ureter or complete with double kidney and bifid or separate ureters]

Question 27

What condition is characterized by fusion of the kidneys at inferior poles? What causes them to sit lower in abdominal cavity?

Answer 27

Horseshoe kidney, sit lower bc their ascent is prevented by inferior mesenteric artery

Question 28

Accessory renal vessels are relatively common with adult kidneys, why are these potentially problematic?

Answer 28

Can obstruct ureter, causing enlarged renal pelvis and hydronephrosis They are end arteries, so if they're damaged can lead to ischemia

Question 29

What are the 3 potential urachal anomalies?

Answer 29

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

Question 30

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 ```

Answer 30

C. At week 10

Question 31

A urachal cyst is a remnant of the: ``` A. Urogenital sinus B. Urogenital ridge C. Cloaca D. Allantois E. Mesonephric duct ```

Answer 31

D. Allantois

Question 32

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

Answer 32

E. A premature division of the ureteric bud

Question 33

The transitional epithelium lining the urinary bladder is derived from: ``` A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells ```

Answer 33

B. Endoderm

Question 34

The transitional epithelium lining the ureter is derived from: ``` A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells ```

Answer 34

C. Mesoderm

Question 35

The podocytes of Bowman's capsule are derived from: ``` A. Ectoderm B. Endoderm C. Mesoderm D. Endoderm and mesoderm E. Neural crest cells ```

Answer 35

C. Mesoderm

Question 36

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 ```

Answer 36

B. Metanephric vesicle

Question 37

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

Answer 37

A. Incorporation of the lower end of the mesonephric ducts

Question 38

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 ```

Answer 38

D. Urachal cyst

Question 39

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 ```

Answer 39

E. Exstrophy of the bladder