Embryology

Question 1

Describe the normal development of the kidney

Answer 1

pronephros- early stage, non-functional
- develops and disappears in week 4

mesonephros
-20 paired tubule that makes some urine in week 5
-contributes to obliteration of cloaca and bladder formation

metanephros
-starts at 6 weeks
-forms the actual kidney in the pelvis then migrates to the lumbar region
-produces urine by 9-10 weeks
-attaches the elongated ureteric bud to the urogenital sinus

Question 2

What are the embryologic origins of the kidney and ureters?

Answer 2

mesonephric ducts

Question 3

What are the embryologic origins of bladder?

Answer 3

urogenital sinus for all parts except the trigone

trigone-mesonephric ducts.

Question 4

What is embrologic origin of the uterus and tubes?

Answer 4

paramesonephric ducts

Question 5

What is the embryologic origin of the male genitalia?

Answer 5

mesonephric ducts (wolffian ducts)
SRY region of the Y chormosome produces mullerian inhibiting substance.

Question 6

What is the embryologic origin of the lower 2/3 of the vagina, vestibule, and rectum?

Answer 6

urogenital sinus

Question 7

Gonadal development

Answer 7

germ cells migrate to the gonadal ridge through the primitive streak

no migrate of germ cells = no gonads

germ cells multiple into several million by month 4

Question 8

Name the embryologic origin of this vulvar structure:

Clitoris

Answer 8

Clitoris: genital tubercle

Question 9

Name the embryologic origin of this vulvar structure:

Labia majora

Answer 9

Labia majora: labioscrotal swellings

Question 10

Name the embryologic origin of this vulvar structure:

labia minora

Answer 10

labia minora: genital tubercle

Question 11

name the embryologic origin of the urethra.

Answer 11

urogenital sinus

Question 12

What structures are formed by the urogenital sinus?

Answer 12

bladder, urethra, paraurethral glands, lower 2/3 of vagina

Question 13

name the embryologic origin of the ureter.

Answer 13

ureteric bud