embryology

Question 1

what 3 main groups is the mesoderm organised into?

Answer 1

Paraxial, Intermediate and Lateral plate

Question 2

what are the urinary and reproductive system derived from?

Answer 2

intermediate mesoderm

Question 3

what are the 3 nephric structures made by the nephrogenic ridge?

Answer 3

pronephros
mesonephros
metanephros

Question 4

where does the mesonephros form and what does it do after?

Answer 4

Forms in the thoracic and upper lumbar region.
Mesonephric tubules lengthen and receive a glomerulus, medially.
Tubule surrounds the glomerulus to form a bowman’s capsule.
Laterally, tubule enters the mesonephric duct.

Question 5

what 2 components form the definitive kidney?

Answer 5

collecting portion and excretory portion

Question 6

describe the collecting portion of the definitive kidney

Answer 6

ureteric buds sprout from caudal mesonephric ducts into metanephric mesenchymal cap

bifurcation of bud forms primitive renal pelvis, then major and minor calyces

continued divisions create pyrimidal arrangement converging on the minor calyx

Question 7

describe the excretory portion of the definitive kidney

Answer 7

metanephric caps cover collecting tubules.

Induces the tissue cap to form vesicles which lengthen and are penetrated by capillaries at one end.

Other end unites with collecting duct.

Further lengthening forms the characteristic nephron.

Question 8

what happens to the urinary system in weeks 4-6?

Answer 8

Descent of the Urorectal septum divides the endoderm cloaca into an anorectal canal and urogenital sinus.
Urognetial sinus forms bladder and urethra
Anorectal canal form rectum and proximal 2/3rds of anal canal.

Question 9

what forms the ductus deferens?

Answer 9

mesonephric duct

Question 10

what aids the formation fo the trigone of the bladder?

Answer 10

Ascent of the kidneys and growth of the bladder draws the ureteric entry to bladder cranially, aiding the formation of the trigone