Urogenital Development

Question 1

What predominately form the urogenital system

Answer 1

Intermediate mesoderm

Question 2

What are the 3 regions of the urogenital system

Answer 2

• Pronephros
• Mesonephros
• Metanephros

Question 3

Pronephros

Arrangement

From

Answer 3

• Segmentally arranged cords (nephrotomes)
• Anterior intermediate mesoderm
• Connected by pronephric ducts
• Degenerates early
  
  • Non functional
  • May concentrate urine but there arent any ducts to secrete it

Question 4

Mesonephros

Composed of what

Answer 4

• Glomerulus surrounded by capsule
• Meonephric tubule extends toward capillary bed from mesonephric duct
• Similar to aquatic animal filter
  *

Question 5

Mesonephric Duct

Primary orientation, stimulate, becomes

Diff between females and males

Develops

Answer 5

• Primary mesonephric ducts
  
  • Extend caudually (next to somites)
  • Stimulate formation of mesonephric tubules
  • Becomes mesonephric (Wolffian) duct
  • Attach to cloaca
• Regress in females
• Remain in males (ductus deferens)
• Develops uteric bud

Question 6

Metanephros

Answer 6

• Uteric bud grows into posterior intermediate mesoderm
  
  • Elongates and branches, becoming collecting duct system
• Metanephric blastema
  
  • cells surrounding metanephric duct (excretory portion)

Question 7

Uteric bud bifurcations

Answer 7

• tip of first ampulla gives rise to renal pelvis
• Uteric bud bifurcates 4 times, 16 branches, which coalesce to form calyces
• Mino calyces are also formed
• will form future collecting tubules and ducts

Question 8

Migration of kidney

Answer 8

• Pelvic to lateral abdominal
• Come in contact with adrenal glands

Question 9

Formation of urinary bladder

Answer 9

• Urogenital sinus continous with allantois
• Base of allantois forms bladder
• Bladder incorporates mesonephric duct and uteric buds

Question 10

Male Sexual duct differentiation

Answer 10

• Sertoli cells secrete Mullerian Inhibiting factor
• Paramesonephric ducts degenerate
• Testosterone stimulates mesonephric ducts to continue to develop
  
  • Ductus deferens

Question 11

Female Sexual Duct Differnetiation

Answer 11

• Absence of Mullerian Inhibitory factor or testosterone
• Mesonephric ducts degenerate
• Paramesonephric ducts continue to develop as oviducts

Question 12

Indifferent External Genitalia

Answer 12

• Genital tuburcle (tip)
• Genital folds (shaft)
• Urogenital sinus (lips)
  
  • Urethral plate
• Genital swellings (aouond base of shaft)

Question 13

Male External Genitalia

Answer 13

• Influenced by DHT
• Genital tuburcle elongates–> penis
• Genital Swellings–> scrotal pouch
• Genital folds fuse closing