Development of the Urinary System

Question 1

intermediate mesoderm

Answer 1

nephrotome.

gives rise to the nephric structures of the embryo, portions of the suprarenal glands, gonads, and genital duct system

Question 2

urogenital ridge

Answer 2

longitudinal elevation of mesoderm from transverse folding

Question 3

divisions of urogenital ridge

Answer 3

nephrogenic cord–urinary system

gonadal ridge– genital system

Question 4

three sets of nephric system that develop craniocaudally from nephrogenic cord

Answer 4

pronephroi–rudimentary and nonfunctional
mesonephroi– functions briefly during the early fetal period, excretory units and ducts
metanephroi–forms the permanent kidneys, most caudal

Question 5

parts of the pronephric ducts used by next set of kidneys

Answer 5

mesonephric ducts, creates metonephric diverticulum (or uteric bud)

Question 6

mesonephroi

Answer 6

excretory organs that appear late in 4th week, caudal to pronephroi. well developed, interim kidneys.

Question 7

parts of the mesonphric kidneys

Answer 7

glomeruli and tubules

tubules open into bilateral mesonephric ducts (from pronephric ducts)

Question 8

embryonic precursors to the efferent ductules of the testes

Answer 8

mesonphric tubules

Question 9

functional adult derivatives of the mesonephric tubules

Answer 9

efferent ductules of testis
paradidymis

epoophoron
paroophoron

Question 10

where do mesonphric ducts open into?

Answer 10

urogenital sinus (cloaca)

Question 11

adult derivative of mesonephric ducts

Answer 11

appendix of epididymis/vesiculosa
duct of epididymis/epoophoron
ductus deferens/longitudinal duct; gartner duct
ureter, pelvis, calices, and collecting tubules of kidneys
ejaculatory duct and seminal gland

Question 12

two parts of the metanephroi

Answer 12

excretory–metanephrogenic blastema (metanephric mass of mesenchyme), derived from caudal part of the nephrogenic cord
collecting–ureteric bud (metanephric diverticulum), from mesonephric duct near its entrance into cloaca

Question 13

reciprocal induction

Answer 13

branching of the urteric bud– dependent on induction by the metanephric mesenchyme
differentiation of the nephrons depends on induction by the collecting tubules.

Question 14

derivatives of nephronic cord and mesonephric duct as two functional parts of kidneys

Answer 14

nephronic cord–excretory, metanephrongenic blastema

mesonephric duct–collecting, uretic bud

Question 15

collecting portion of kidney (ureteric bud)

Answer 15

ureter
renal pelvis
major and minor calyces
collecting ducts
collecting tubules

Question 16

excretory portion (nephron) (metanephric blastema)

Answer 16

bowman’s capsule
proximal convoluted tubule
loop of henle
distal convoluted tubule

Question 17

the second branching of ureteric bud and it’s stalk

Answer 17

stalk of ureteric bud= ureter

5-8=minor calices
second set of branching make minor calices coalesce via intussusception

Question 18

development of the excretory portion of kidney

Answer 18

caudal part of the nephrogenic cord–>metanephrogenic blastema–>(meta)nephric vesicles elongate to (meta)nephric tubules which develop into the nephron (proximal/distal convoluted tubules, bowman’s capsule, loop of henle) due to invagination of proximal ends of glomeri

Question 19

what constitutes a nephron

Answer 19

proximal and distal convoluted tubules, nephron loop (henle loop), glomerulus and capsule

Question 20

when is the upper limit of glomeruli reached?

Answer 20

32nd week, nephron formation is complete at term. 2 million nephrons.
week nine, glomerular filtration begins

Question 21

which convoluted tubule contains arched collecting tubule

Answer 21

distal convoluted

Question 22

urine productivity

Answer 22

10-11th week begins
late pregnancy–500ml of urine added daily
700-1000ml by week 37

Question 23

positional changes of kindeys

Answer 23

metanephric structures in pelvis, ventral to sacrum
ascent
medial rotation
retroperitoneal positioning

Question 24

relocation of the kidneys to the abdomen and movement farther apart

Answer 24

disproportionate growth of the embryo’s body caudal to the kidney. this makes them contact suprarenal gland. normal adult position by 9th week.

Question 25

during kidney ascension, they also

Answer 25

medially rotate 90 degrees, ventral location of hilum is changed to anteromedially

Question 26

changes in blood supply to the kidneys

Answer 26

``` renal arteries (common illiac branches) from descending abdominal aorta distal end of aorta new branches from the aorta and the caudal branches of renal vessels disappear=permanent renal arteries ```

Question 27

permanent renal arteries

Answer 27

branches from the abdominal aorta, right renal is longer and often more superior

Question 28

renal agenesis

Answer 28

ureteric buds do not develop or the primordia (stalks of buds) of the ureters degenerate. if the buds do not penetrate metanephrogenic blastema, the nephrons are not induced by collecting tubules to develop from metanephrogenic blastema.

Question 29

clinical associations with renal agenesis

Answer 29

unilateral--males, left kidney. usually unnoticed. suspected with kids in single umbilical artery bilateral--oligohydromnios, incompatible with life. pulmonary hypoplasia. potter sequence--bilateral renal angenesis.

Question 30

malrotated kidneys

Answer 30

hilum is anterior, fetal retains embryonic position. hilum is posterior, too far rotation. hilum is lateral, lateral rotation instead of medial. associated with: ectopic kidneys

Question 31

ectopic kidneys

Answer 31

malrotation usually located in pelvis (some inferior abdomen) internal or external iliac arteries or abdominal aorta remain blood supply. pelvic kidneys-- kidneys fail to ascend

Question 32

pancake kidneys (discoid)

Answer 32

pelvic kidneys (failure to ascend) are too close together. remain in pelvic region

Question 33

horseshoe kidney

Answer 33

inferior poles of two metanephroi fuse, crossing over ventral aorta pubic region (anterior to inferior lumbar vertebra) caught under inferior mesenteric artery during ascent normal collecting systems, ureters in bladder-- no symptoms

Question 34

congenital polycystic kidney disease

Answer 34

autosomal recessive or dominant ARKPD- at birth or in utero, both kidneys contain many small cysts, early life renal failure. death shortly after birth ADKPD-- more common, cysts in all regions of nephrons, less severe than recessive. associated with cysts in kidneys, ductal epithelia in the liver, pancreas, testis, and ovary

Question 35

duplicated ureter

Answer 35

abnormal divisions of ureteric bud. premature bifurcation before it enters the substance of the metanephric blastema often, but not always asymptomatic. predisposition to infections

Question 36

ectopic ureter

Answer 36

does not enter urinary bladder (not incorporated into trigone), drains somewhere else males-neck of bladder, prostatic part of urethra, ductus deferens, prostatic utricle, seminal gland females-neck of bladder, urethra, vagina, or vestibule of vagina

Question 37

common complaint of ectopic ureter

Answer 37

incontinence, urine flowing does not enter bladder. continual dribble. UTI

Question 38

3 parts of urogenital sinus

Answer 38

vesical part pelvic part phallic part

Question 39

vesical part of urogenital sinus

Answer 39

most of the bladder and continuous with allantois

Question 40

pelvic part of urogenital sinus

Answer 40

urtethra in the neck of the bladder, prostatic part of the urethra in males, and entire urethra in females

Question 41

phallic part

Answer 41

grows toward the genital tubercle (primordium of the penis or clitoris)

Question 42

what develops from the vesical part of the urogenital sinus

Answer 42

bladder

Question 43

trigone of the bladder

Answer 43

triangular area base of the bladder between the openings of the ureters, derived from the caudal ends of the mesonephric ducts

Question 44

distal parts of mesonphric ducts

Answer 44

incorporated into dorsal wall of bladder as it englarges, contribute to the formation of the CT of the trigone.

Question 45

movement of orifices of ureters due to traction exterted by kidneys as they extend

Answer 45

superolaterally and enter obliquely through base of bladder

Question 46

males vs females, orifices of mesonephric ducts

Answer 46

males move closer together and enter prostatic part of urethras as the caudal parts develop into ejaculatory ducts females- distal ends degenerate

Question 47

epithelium of bladder is derived from

Answer 47

endoderm of the vesical part of the urogential sinus

Question 48

other layers of bladder

Answer 48

adjacent splanchnic mesenchyme

Question 49

urachus

Answer 49

thick fibrous cord that is a result of the allantois constricting. extends apex of the bladder to umbilicis. initially bladder is continuous with allantois. the median umbilical ligament

Question 50

the urinary system consists of

Answer 50

kidneys, ureters, urinary bladder, urethra | by weeks 8-12.

Question 51

allantois and blood vessels

Answer 51

sausage-like diverticulum from caudal wall of umbilical vesicle extending into connecting stalk. these blood vessels become umbilical vessels

Question 52

urachus

Answer 52

proximal part of the allantoic diverticulum, from bladder to umbilical region. become median umbilical ligament, from the apex of the urinary bladder to the umbilicus

Question 53

urachal fistula

Answer 53

urine drains from its umbilical orifice and increases risk of UTI, proximal

Question 54

umbilical urachal sinus

Answer 54

abcesses, proximal. urine leak through umbilical opening

Question 55

vesicourachal diverticulum

Answer 55

increases risk for UTI,

Question 56

urachal cyst

Answer 56

not usually detected except during postmortem, unless infected. life threatening if ruptures in peritoneal cavity

Question 57

extrophy of bladder

Answer 57

males. exposure and protrusion of the muscosal surface of the posterior wall of the bladder. trigone of bladder and ureteric orifices are exposed. everted bladder. epispadias (urethra opens on dorsum of penis), wide separation of pubic bones **** deficiency of anterior abdominal wall, incomplete median closure of the inferior part of the wall. abdominal wall and anterior wall of urinary bladder.

Question 58

most of male urethra, entire female

Answer 58

derived from endoderm of the urogenital sinus

Question 59

distal part of male urethra and epithelium of the terminal part of the urethra

Answer 59

in glans of penis, derived from solid cord of ectodermal cells, that grow inward from tip of glans. terminal-- surface ectoderm

Question 60

connective tissue and smooth muscles around both urethra

Answer 60

splanchnic mesoderm

Question 61

two areas of suprarenal glands

Answer 61

cortex--mesenchyme on each side of embryo between the root of dorsal mesentary and the developing gonad medulla--adjacent sympathetic ganglion, neural crest cells

Question 62

at birth, which part of suprarenal gland is larger

Answer 62

extensive cortex, produces steroid precursors that are used by placenta for estrogen synthesis smaller medulla rapidly becomes smaller as the fetal cortex regressed during first year of infancy

Question 63

Congenital Adrenal Hyperplasia

Answer 63

autosomal recessive disorders that result in virilization of female fetuses. genetic deficiency of suprarenal cortical enzymes (cortex) increased release of adrenocorticotropin from anterior pituitary gland

Question 64

increased release of adrenocoritcotropin

Answer 64

abnormal increase in cells of the suprarenal cortex and excessive androgen production masculinization of external genitalia

Question 65

Wilms Tumor

Answer 65

Mesodermal tumor, metanephric tissue has failed to differentiate into normal kidney tissue. rapid growth, early metastasis. high survival rates Asymptomatic abdominal mass Malaise, anemia, weight loss Occlusion of left renal vein

Question 66

Hypospadias/Epispadias

Answer 66

hypospadia--urthral opening on ventral side of the penis | epispadia--urtethral opening on dorsal side of penis