Embryology of the Kidney

Question 1

what 4 parts are the urinary system made up of

Answer 1

kidneys
ureters
urinary bladder
urethra

Question 2

what two parts are the reproductive system made up of

Answer 2

internal/external genitalia

Question 3

when does the formation of the pronephros occur

Answer 3

4th week

Question 4

describe the formation of the pronephros

Answer 4

intermediate mesoderm in the cervical region condenses and reorganises
forms epithelial buds - disappear around day 25

Question 5

how does the mesonephric duct form

Answer 5

intermediate mesoderm in the lower cervical region induced to epithelise forming a solid duct

Question 6

what does the mesonephric duct fuse with and on what day

Answer 6

cloaca on day 26 (develops caudally)

Question 7

what is the formation of the mesonephros derived from

Answer 7

intermediate mesoderm in upper thoracic to upper lumbar regions

Question 8

what does the development of the mesonephric duct induce

Answer 8

formation of the mesonephric buds from mesenchyme

Question 9

formation of the mesonephric tubules occur in what fashion

Answer 9

carniocaudally

Question 10

what do mesonephric tubules differentiate into

Answer 10

S shape and bowman capsule

Question 11

what is the renal corpuscle made from

Answer 11

bowman capsule and glomerulus

Question 12

what is the glomerulus made out of

Answer 12

tuft of capillaries which form at the medial end of the tubule

Question 13

how many of the cranial-most tubules fun with the mesonephric duct

Answer 13

6/7

Question 14

when do the tubules first start producing small amounts of urine

Answer 14

between weeks 6-10

Question 15

what happens to the mesonephric ducts after week ten

Answer 15

males - develop into reproductive structures

females - regress

Question 16

where does gonadal development take place

Answer 16

on the medial aspect of the mesonephric ridge

Question 17

what parts make up the collection portion

Answer 17

collecting ducts
major and minor calyces
renal pelvis
ureter

Question 18

what parts make up the excretory portion

Answer 18

bowmans capsule
PCT
LoH
DCT

Question 19

what happens to the ureteric buds by day 32

Answer 19

penetrate the metanephric mesenchyme

Question 20

what is the biurification pathway after the ureteric bud penetrates the metanephric mesenchyme

Answer 20

renal ampulla
renal pelvis 
major calyces 
minor calyces 
collecting ducts

Question 21

what covers newly formed collecting tubules

Answer 21

metanephric tissue cap

Question 22

what does the metanephric tissue cap cause

Answer 22

specific branching of the tubule

differentiation of cells in the metanephric cap to form renal vesicle

Question 23

what does the renal vesicle turn into

Answer 23

s shape tubule and bowman capsule

Question 24

what 3 parts make up the nephron

Answer 24

renal corpuscle, tubule and collecting tubule

Question 25

describe duplication of the ureter

Answer 25

premature biurification of the ureteric bud can be partial or complete present in approx 5%

Question 26

describe unilateral and bilateral renal genesis

Answer 26

early degeneration of ureteric bud or failed interaction between ureteric and meseneohric tissue cap unilateral - generally asymptomatic, hypertrophy of remaining kidney bilateral - incompatible with life

Question 27

what is oligohydraminos

Answer 27

bilateral renal agenesis | decreased volume amniotic fluid causing the foetus to present with potter sequence

Question 28

describe polycystic kidney disease

Answer 28

autosomal dominant occurs 1 in 1000 cysts form on all parts of the nephron autosomal recessive 1 in 5000 cysts form in collecting ducts and kidneys enlarge to renal failure in childhood caused by gene mutations in cilia

Question 29

what is ascent of kidneys caused by

Answer 29

growth and elongation of developing foetus

Question 30

by what week do kidneys fully relocate

Answer 30

week 9

Question 31

what is horseshoe kidney

Answer 31

occurs in around 1/600 people inferior poles of kidney fuse resides lower in the lumbar region usually asymptomatic

Question 32

what happens to the cloaca in week 4-7

Answer 32

divides into the urogenital sinus and the anal canal which are separated by urorectal septum

Question 33

what is the urogenetial sinus divided into

Answer 33

upper part - presumptive urinary bladder pelvic part - urethra phallic part - penile urethra (males), vestibule (females)

Question 34

what is the bladder initially continuous with

Answer 34

allantois

Question 35

what happens to the allantois

Answer 35

obliterates to form the urachus that connects the apex of the bladder with the umbilicus in the adult