Embryology

Question 1

What is the condition characterized by the failure of the paramesonephric ducts to fuse completely?

Answer 1

Bicornuate uterus

Increased risk includes infertility, preterm delivery, and fetal malformations.

Question 2

What is the result of dysfunction of sinuvaginal bulbs in females?

Answer 2

Imperforate hymen

Clinical features include primary amenorrhea and cyclic pelvic pain.

Question 3

What syndrome is caused by a mutation of MIF receptors, preventing regression of the paramesonephric duct?

Answer 3

Persistent Müllerian duct syndrome

This condition results in both male and female internal structures.

Question 4

What are the remnants of the mesonephric duct found in females?

Answer 4

Epoöphoron and paroöphoron

These remnants are located on the mesosalpinx and mesovarium.

Question 5

What embryological structure develops into the fallopian tubes, uterus, cervix, and upper 1/3 of the vagina?

Answer 5

Paramesonephric (Müllerian) duct

Question 6

Which cells produce Müllerian inhibiting factor (MIF)?

Answer 6

Sertoli cells

Question 7

What is the clinical presentation of a patient with an imperforate anus?

Answer 7

Failure to pass meconium

This condition is associated with VACTERL association.

Question 8

Fill in the blank: The _______ is responsible for the differentiation of indifferent gonads into testes.

Answer 8

Sex determining transcription factor

Question 9

What is the consequence of a mutation in 5-alpha reductase?

Answer 9

5 alpha reductase deficiency

This condition leads to a normal male internal structure but ambiguous external structures.

Question 10

True or False: Ovaries are formed from the paramesonephric ducts.

Answer 10

False

Ovarian function is independent of paramesonephric structures.

Question 11

What is the embryological origin of the lower 2/3 of the vagina?

Answer 11

Urogenital sinus

Question 12

What are the male internal structures produced by the mesonephric duct?

Answer 12

• Epididymis
• Vas deferens
• Seminal vesicle
• Ejaculatory duct

Question 13

What is the condition characterized by the opening of the penile urethra on the ventral surface of the penis?

Answer 13

Hypospadias

Question 14

What is the result of androgen insensitivity syndrome in a 46, XY individual?

Answer 14

Ambiguous external structures, appears female

Hormone production is normal, but there is a mutation or absence of androgen receptors.

Question 15

What is the function of Leydig cells in male embryonic development?

Answer 15

Produce testosterone

Testosterone maintains the mesonephric duct.

Question 16

Fill in the blank: The _______ duct is essential for the development of male external genitalia.

Answer 16

Mesonephric

Question 17

What are the components of the urogenital sinus in males?

Answer 17

• Prostatic urethra
• Membranous urethra
• Prostatic utricle
• Prostatic gland
• Bulbourethral glands

Question 18

What embryological structure forms the scrotum in males?

Answer 18

Labioscrotal swellings

Question 19

What is the consequence of testosterone not being converted to dihydrotestosterone (DHT) during male development?

Answer 19

Disintegration of the mesonephric duct

Question 20

Which embryological structure is responsible for the development of the glans penis?

Answer 20

Genital tubercle

Question 21

What is the result of incomplete fusion of urethral folds in males?

Answer 21

Hypospadias

Question 22

What happens to the mesonephric duct in the absence of testosterone?

Answer 22

It disintegrates

Question 23

What does the term ‘indifferent gonad’ refer to?

Answer 23

The early stage of gonad development before sexual differentiation

Question 24

Fill in the blank: The _______ is a remnant of the paramesonephric duct in males.

Answer 24

Appendix of testis

Question 25

What are the secondary sex characteristics that develop in androgen insensitivity syndrome?

Answer 25

Female

Question 26

What is the role of primordial germ cells in female embryology?

Answer 26

They migrate from the yolk sac to the undifferentiated gonad and induce differentiation of the ovary.

Question 27

What embryological structures are derived from the urogenital sinus in females?

Answer 27

* Lower 2/3 of vagina * Membranous urethra * Bartholin's glands * Skene's glands

Question 28

What is the embryological origin of the upper 1/3 of the vagina?

Answer 28

Paramesonephric duct

Question 29

What is the clinical significance of cryptorchidism?

Answer 29

Increased risk of malignancy or infertility ## Footnote It occurs when one or both testes fail to descend.

Question 30

What is the title of the book authored by Harrison?

Answer 30

Harrison's Principles of Internal Medicine

Question 31

Which edition of Harrison's Principles of Internal Medicine was published in 2011?

Answer 31

18th ed.

Question 32

Who are the authors of Larsen's Human Embryology?

Answer 32

G.C. Schoenwolf, S.B. Bleyl, P.R. Brauer, P.H. Francis-West

Question 33

What is the edition number of Larsen's Human Embryology published in 2009?

Answer 33

4th ed.

Question 34

In which cities was Larsen's Human Embryology published?

Answer 34

New York; Edinburgh

Question 35

Who is the publisher of Harrison's Principles of Internal Medicine?

Answer 35

McGraw-Hill Medical Publishing

Question 36

What is the publisher of Larsen's Human Embryology?

Answer 36

Churchill Livingstone

Question 37

What type of link is provided for lecture feedback?

Answer 37

Survey link

Question 38

Fill in the blank: Harrison's Principles of Internal Medicine was published in _______.

Answer 38

2011

Question 39

Fill in the blank: Larsen's Human Embryology is in its _______ edition.

Answer 39

4th

Question 40

True or False: Harrison's Principles of Internal Medicine is a textbook on internal medicine.

Answer 40

True

Question 41

primordial germ cells migrate from this embryonic structure to the undifferentiated gonads

Answer 41

yolk sac

Question 42

testosterone is required to maintain what embryonic structure?

Answer 42

mesonephric wolffian duct

Question 43

the mesonephric duct gives rise to the ureteric bud which gives rise to what structures?

Answer 43

distal urinary tract: ureter, renal plevelis, calyces, CD, CTs

Question 44

the mullerian paramesonephric duct gives rise to what structures?

Answer 44

fallopain tubes uterus cervix upper 1/3 vagina

Question 45

T or F: ovary function depends on paramesonephric structures

Answer 45

false ovaries are not formed from this duct; therefore estrogen production and secondary sex characteristics develop independently

Question 46

what endodermal swellings in the urogenital sinus fuse to form the vaginal plate.

Answer 46

sinuvaginal bulbs

Question 47

what are the symptoms of imperforate hymen

Answer 47

primary amenorrhea and cyclic pelvic pain rectal exam-cystic mass of accumulated menstrual blood

Question 48

sertoli cells express what gene that drives male differentiation of the gonads?

Answer 48

SRY

Question 49

sertoli cells produce this protein which causes regression of the paramesonephric duct

Answer 49

MIF

Question 50

T or F: a pt. w/ persistent mullerian duct syndrome will have internal characteristics of male and female but exculsively male features of the external genitilia and secondary sex characteristics

Answer 50

true

Question 51

List the components of the VACTERL acronym for imperforate Anus

Answer 51

vertebral anomalies anal atresia cardiovascular abnormalities TEF esophageal atresia renal anomalies limb defects

Question 52

What is the function of the 5alpha-reductase

Answer 52

conversion of testosterone to DHT

Question 53

development of what male structures requires DHT

Answer 53

male external genitalia

Question 54

what is the definition of cryptorchidism?

Answer 54

failure of one or both testes to descend

Question 55

the genital tubercle forms what external genitalia components?

Answer 55

glans penis/clitoris corpus cavernosum spongiosum (males only)

Question 56

what doe the urogenital folds form in the male and female respectively?

Answer 56

males: penile urethra ventral penis females: labia minora

Question 57

what doe the labioscrotal swellings form in the male and female respectively?

Answer 57

males: scrotum females: labia majora

Question 58

what is the pathogenesis of androgen insensitivity syndrome

Answer 58

mutation or absence of androgen receptors on target tissues leading to lack of internal structures

Question 59

what do the external genitalia of a male w/ 5-alpha reductase deficiency appear as?

Answer 59

ambiguous female features

Question 60

T or F: lack of DHT does not affect development of the internal structures and male secondary characteristics

Answer 60

true

Question 61

failure of fusion of the urethral folds will result in what?

Answer 61

opening of penile urethra on the ventral surface of the penis AKA Hypospadias

Question 62

improper positioning of the genital tubercle will result in what?

Answer 62

opening of the penile urethra on the dorsal side of the penis AKA: epispadias

Question 63

Make sure to review this slide on the repro emby. PPT and go through the practice questions.

Answer 63

25