Embryology

Question 1

Sertoli Cells

Answer 1

• Derived from testis surface epithelium
• Start producing AMH during week 8

Question 2

Role of AMH

Answer 2

Suppresses development of the paramesonephric ducts (uterus and other derivatives)

Question 3

Spermatogonia

Answer 3

Primordial sperm cells (derived from primordial germ cells) making up the germinal epitheliun

Question 4

Interstitial Cells (Leydig Cells)

Answer 4

• Arise from mesenchyme surrounding seminiferous tubules
• Androgens induce masculine differentiation of mesonephric ducts and external genitalia (8th week)
• Produce testosterone

Question 5

Once ovary separates from mesonephros, it is suspended by:

Answer 5

Mesovarium

Question 6

Caudal ends of the Paramesonephric duct fuse to form the ____ _____ which projects into the dorsal wall of the urogenital sinus, forming the ___ ___

Answer 6

• Uterovaginal Primordium
• Sinus Tubercle

Question 7

Indifferent Gonad
(1) Male Structure:
(2) Female Structure:

Answer 7

(1) Testis
(2) Ovary

Question 8

Primordial Germ Cell
(1) Male Structure:
(2) Female Structure:

Answer 8

(1) Spermatogonia
(2) Oogonia

Question 9

Somatic Support Cell
(1) Male Structure:
(2) Female Structure:

Answer 9

(1) Sertoli Cells
(2) Follicle Cells

Question 10

Stromal Cells
(1) Male Structure:
(2) Female Structure:

Answer 10

(1) Leydig Cells
(2) Thecal Cells

Question 11

Gubernaculum
(1) Male Structure:
(2) Female Structure:

Answer 11

(1) Gubernaculum testis
(2) Cranial Part: Ovarian Ligament
Caudal Part: Round Ligament of the Uterus

Question 12

Male Extension of the Transversalis Fascia

Answer 12

Internal Spermatic Fascia

Question 13

Male Extensions of the Internal Oblique Muscle and Fascia:

Answer 13

Cremasteric Muscle and Fascia

Question 14

Male Extension of the External Oblique Muscle and Aponeurosis:

Answer 14

External Spermatic Fascia

Question 15

During the perinatal period in a male, the connecting stalk of the processus vaginalis obliterates and becomes:

Answer 15

Tunica Vaginalis

Question 16

Mesonephric Tubules
(1) Male Structure:

Answer 16

Efferent Ducts of Testis (Efferent Ductules), Paradidymis

Question 17

Mesonephric Duct
(1) Male Structure:

Answer 17

(1) Appendix of Epididymis, Epididymis, Ductus Deferens, Seminal Vesicle, Ejaculatory Duct

Question 18

Paramesonephric Ducts
(1) Male Structure:
(2) Female Structure:

Answer 18

(1) Appendix of the Testis
(2) Uterine Tubes (cranial segments of ducts), Uterus and Superior Part of Vagina (fused caudal portion form uterovaginal primordium which then forms these structures)

Question 19

Endometrial Stroma and Myometrium are derived from:

Answer 19

Splanchnic Mesenchyme

Question 20

Fusion of the Paramesonephric Ducts also forms the:

Answer 20

• Broad Ligament
• Rectouterine Pouch
• Vesicouterine Pouch

Question 21

What forms the mesenchyme inbetween layers of the Broad Ligament?

Answer 21

Parametrium

Question 22

Urogenital Sinus
(1) Male Structure:
(2) Female Structure:

Answer 22

(1) Prostatic and Membranous Urethra, Prostatic Utricle, Prostate Gland, Bulbourethral Glands
(2) Inferior Part of Vagina, Membranous Urethra, Urethral/Paraurethral Glands, Greater Vestibular Glands

Question 23

Genital Tubercle
(1) Male Structure:
(2) Female Structure:

Answer 23

(1) Glans Penis, Corpus Cavernosa of Penis, Corpus Spongiosunm of Penis
(2) Glans Clitoris, Corpus Cavernosa of Clitoris, Bulbospongiosum of Vestibule

Question 24

Labioscrotal Folds
(1) Male Structure:
(2) Female Structure:

Answer 24

(1) Scrotum
(2) Labia Majora

Question 25

Fibromuscular wall of vagina develops from surrounding:

Answer 25

Mesenchyme

Question 26

Development of Vagina

Answer 26

Sinus Tubercle induces paired endodermal outgrowths called the Sinovaginal Bulbs which extend from the Urogenital Sinus –> fuse with Uterovaginal Primordium to form the Vaginal Plate –> cells of vaginal plate canalize to form the vaginal lumen –> invaginations of posterior wall of urogenital sinus form hymen which separates the lumen of the vagina from the urogenital sinus

Question 27

Vaginal epithelium is derived from:

Answer 27

Vaginal Plate

Question 28

Genital Tubercle

Answer 28

• Ectodermal-covered mesodermal swelling at ventral and cranial end of phallic portion of urogenital plate
• Eventually elongates to form a primordial phallus (penis or clitoris)

Question 29

Urethral Plate forms in ventral side of the Primordial Phallus, extending from Phallic Portion of Urogenital Sinus, and later canalizes and opens to form the:

Answer 29

Urethral Groove which is bounded by Urethral Folds

Question 30

Urethral Groove is lined with ____ ___ and forms the ____ ___

Answer 30

• Endodermal Cells
• Urethral Plate

Question 31

Urethral Folds fuse ventrally to form the:

Answer 31

Spongy Urethra

Question 32

(M) Stroma of the Urethral Folds form a portion of the:

Answer 32

Spongiosum

Question 33

(M) Surface Ectoderm of the Urethral Folds form the:

Answer 33

Penile Raphe (encloses spongy urethra)

Question 34

(M) Corpora Cavernosum and Corpus Spongiosum develop from ____ in the phallus

Answer 34

Mesenchyme

Question 35

(F) Urethral Folds fuse posteriorly, and join to from the:

Answer 35

Frenulum of the Labia Minora

Question 36

(F) Unfused parts of the Urogenital Folds form the:

Answer 36

Labia Minora

Question 37

Parts of the Labioscrotal Folds that do not fuse form:

Answer 37

(1) Posterior Labial Commissure
(2) Anterior Labial Commissure and Mons Pubis

Question 38

Processus Vaginalis in the female usually obliterates and disappears before birth, but if it persists then it is known as:

Answer 38

Processus Vaginalis of the Peritoneum (Canal of Nuck)