10 - Renal Embryology Flashcards
This is located in the trunk and is immediately lateral to each somite. It segments into cylindrical structures.
Intermediate Mesoderm
This is what produces the urinary system and parts of the genital system. The urinary system develops first.
Intermediate Mesoderm
This is a longitudinal band of mesoderm that forms on each side of the dorsal aorta.
Urogenital Ridge
A portion of the urogenital ridge will form the…
Nephrogenic Cord
The Nephrogenic Cord gives rise to what nephric structures?
Pronephros
Mesonephros
Metanephros
What are the functions of the three nephric structures?
Proenphros = Rudimentary
Mesoenphros = Functions briefly during early fetal period
Metanephros = Permanent kidneys
Briefly explain the steps from the Urogenital Ridge to reach the permanent kidneys.
Urogenital Ridge --- Nephrogenic Cord --- Pronephros --- Mesonephros --- Metanephros (Permanent Kidneys)
These are bilateral, transitory structures that appear early in the 4th week. Located in cervical region.
Proenphros
Pronephric ducts run caudally and open into the ________.
Cloaca
The pronephros degenerate by ________ days, but the pronephric ducts persist and are used by _________.
24-25
Mesonephros
Pronephros are important because they initiate the cascade leading to formation of the definitive ________.
Kidney
These are bilateral, transient structures that appear late in the 4th week. They are caudal to pronephros.
Mesonephros
The Mesonephros includes the _________ _________ and _________ _________.
Mesonephric Ducts
Mesonephric Tubules
The Mesonephric Ducts develop first and induce the Mesonephric Tubules to form from surrounding…
Intermediate Mesoderm
Mesonephric Tubules will from ________ ________.
Renal Corpuscles
For the Mesonephric Tubules, the medial end of them is a cup-shaped ________ ________ that wraps around a ________ (knot of capillaries).
Glomerular Capsule
Glomerulus
These function as interim kidneys from 6-10 weeks, producing small amounts of urine.
Mesonephric Tubules
After 10 weeks, the Mesonephric Tubules stop functioning. They will regress in females and form ________ _______ in males. These degenerate by _______ weeks.
Efferent Ductules
12
This arises during the 5th week and is the caudal end of each Mesonephric Duct. It induces the Ureteric Bud.
Metanephros
What does the Metanephros form?
Ureteric Bud (Collecting Portion) = outgrowth of Mesonephric Duct
Metanephric Blastema (Excretory Portion) = from Nephrogenic Cord
The Metanephros forms the functional and definitive ________ by the 9th-10th week.
Kidney
Definitive kidneys have what two portions?
Excretory Portion
Collecting Portion
The Ureteric Bud (part of Metanephros) elongates and penetrates the ________, to form the _______ _______.
Blastema
Renal Pelvis
The stalk of the Ureteric Bud becomes the…
Ureter
The cranial part of the bud branches are the ________ _______.
Collecting Tubules
The 1st generations (4) of collecting tubules enlarge and become ________ ________. 2nd generations (4) become ________ _______.
Major Calices
Minor Calices
Describe the steps of Nephron development.
1) Arched collecting tubule induces cells of metanephrogenic blastema to form metanpehric vesicles.
2) Vesicle will elongate to form metanephric tubules.
3) Proximal end will form glomerular capsule, is invaded by glomeruli.
4) Other end of the tubule lengthens and differentiates into PCT, DCT, and Nephron loop.
5) Each DCT contacts an arched collecting tubule – Now connected.
Permanent kidneys lie within the pelvis and gradually ascend into the abdomen. The ________ medially rotates 90 degrees, and the adult position is reached by the 9th week. At this point they’re in contact with _______ _______.
Hilum
Suprarenal Glands
The kidneys receive blood supply from vessels that are the closest. The first branch form from ________ _______, and the definitive _______ _______ are from the abdominal aorta. Former branches undergo involution and disappear.
Common Iliacs
Renal Arteries
What adult structures does the Ureteric Bud (Collecting Portion) form?
Ureter
Renal Pelvis
Major and Minor Calyces
Collecting Ducts
What adult structures does the Metanephric Blastema (Excretory Portion) form?
Bowman’s Capsule
Proximal Convoluted Tubule (PCT)
Loop of Henle
Distal Convoluted Tubule (DCT)
This is a congenital anomaly that occurs when one of the kidneys doesn’t form. Occurs in 1:1,000 and is more frequent in males. Typically asymptomatic. Suspected in infants with 1 umbilical artery.
Unilateral Renal Agenesis
This is a congenital anomaly that occurs when neither of the kidneys forms. Occurs in 1:3,000. Oligohydramnios occurs, and is nonviable – pulmonary hypoplasia. Can also occur in Potter Syndrome (20%).
Bilateral Renal Agenesis
What are the type of duplications that can occur with the kidney/ureter?
– Abnormal division of ureteric bud
– Incomplete division = divided kidney and bifid ureter
– Complete division = double kidney and bifid ureter or separate ureters
This type of congenital anomaly occurs from the fusion of inferior poles. It is asymptomatic and ascent is prevented by IMA. Occurs in 1:1000.
Horseshoe Kidney
This congenital anomaly is when there are accessory renal vessels. There are multiple renal arteries (2-4). Occurs in about 25% of adult kidneys, and is 2x common as accessory veins. These can obstruct the ureter, which leads to __________. These are end arteries, so if damaged or ligated it can cause ischemia.
Hydronephrosis
This disease is an autosomal recessive mutation of PKHD1. Cysts present in both kidneys and there is renal insufficiency. 25% associated with pulmonary hypoplasia.
Polycystic Kidney Disease
This disease is abnormal development of the renal system. Cysts are likely dilations of Loop of Henle. One kidney is affected (75%).
Multicystic Dysplastic Kidney Disease
The Ventral Cloaca (distal hindgut) contains the ________ ________ and anorectal canal. These regions are separated by the ________ ________.
Urogenital Sinus
Urorectal Septum
The Urogenital Sinus is critical for bladder and urethral development. What are its parts?
1) Vesical Part = Forms most of urinary bladder
2) Pelvic Part = Forms neck of bladder; Prostatic urethra (m) and urethra (f)
3) Phallic Part = Forms spongy urethra (m) and lining of vaginal vestibule (f)
Between 4-6 weeks, the Mesonephric Duct is incorporated into the posterior wall of the _________.
Bladder
T/F. The Ureteric Bud is also attached, which will connect the openings of the Ureteric Buds into the bladder wall.
True
Openings of the Mesonephric Duct are carried inferiorly to the _______ _______. Forms the ________, the triangular region of the Mesonephric and Ureteric Ducts blending into the posterior bladder.
Pelvic Urethra
Trigone
This develops mainly from the vesical part of the urogenital sinus.
Bladder
What are the parts of the bladder and what embryonic layer are they derived from?
Epithelium = Endoderm (Urogenital Sinus)
Submucosa and Muscularis = Splanchnic Mesoderm
Trigone = Intermediate Mesoderm (Mesonephric Ducts)
The bladder is continuous with the _________, the fetal membrane developed from the hindgut.
Allantois
The Allantois constricts and forms the ________. It extends from the apex of the bladder to the _________. This will eventually form the ________ ________ ________.
Urachus
Umbilicus
Median Umbilical Ligament
This congenital anomaly arises during body folding (4th week) and is a defective closure of the ventral abdominal wall. There is exposure of mucosa of the posterior wall of bladder. Occurs in 1:10-14,000, typically in males.
Exstrophy of the bladder
This congenital anomaly is a urethral opening on the dorsum of the genital tubercle rather than on its ventral side. Occurs in 1:30,000 males. Exstrophy of the bladder with this occurs in 1:40,000.
Epispadias
This anomaly is remnants of the epithelial lining of the urachus that can become infected and enlarged.
Urachal Cysts
This anomaly is when the end of the urachus remains open into the bladder (inferior region) or umbilicus (superior region).
Urachal Sinus
This anomaly is when the entire urachus remains patent and allows urine to escape from the umbilical orifice.
Urachal Fistula
What are the parts of the Suprarenal Gland?
Cortex
Medulla
What are the parts of the Cortex of Suprarenal Gland, and what do they produce?
Zona Glomerulosa = produces mineralocorticoids (regulate electrolytes)
Zona Fasciculata = produces glucocorticoids (regulate blood glucose levels, lipid metabolism)
Zona Reticularis = produces sex hormones, estrogen and testosterone-related hormones (protein synthesis in sex cells)
The Medulla (Suprarenal Gland) consists of _________ cells that secrete _______ and ________.
Chromaffin
NE
Epi
Describe the development of the Suprarenal Gland.
1) 5th week, coelomic epithelium delaminates and enters surrounding mesoderm — fetal cortical cells
2) NCC migrate into the Medulla and will differentiate into Chromaffin cells and postganglionic sympathetic neurons (Epi/NE)
3) Fetal cortex regresses (2nd month PN). Definitive cortical cells reorganize: zona glomerulosa, zona fasciculata, and zona reticularis (adult)
The fetal cortex will secrete ________. This is converted by the placenta to ________, which is essential for maintaining pregnancy. It also secretes ACTH and glucocorticoids.
DHEA
Estradiol
