TBL23 - Female Genitalia

Question 1

What does estrogen from the developing ovaries stimulate in the genital tubercle? What does the corpus cavernosa form in the body of the clitoris?

Answer 1

1) Estrogen from the developing ovaries stimulates slight elongation of the genital tubercle to form the clitoris
2) The corpus cavernosa form the erectile tissue in the short body of the clitoris

Question 2

What do the urethral folds become and what does this demarcate? What surrounds the labia minora and what are these thick folds derived from? Where do the labia majora merge?

Answer 2

1) The urethral folds become the thin labia minora that demarcate the open vestibule
2) The labia majora, thick folds derived from the genital swellings, surround the labia minora
3) The labia majora merge anteriorly to form the mons pubis

Question 3

In the vestibule, what is the vaginal orifice posterior to? What is the urethra derived from?

Answer 3

1) In the vestibule, the vaginal orifice is posterior to the external urethral orifice
2) The urethra is derived from the inferior portion of the urogenital sinus

Question 4

What are the main constituents of the vulva (aka female genitalia)? Where does lymph from the vulva drain into?

Answer 4

1) The clitoris, labia majora and minora, vestibule, and mons pubis are main constituents of the vulva (aka female genitalia)
2) Lymph from the vulva drains into the superficial inguinal lymph nodes

Question 5

In the superficial perineal pouch, what is covered by the bulbospongiosus muscles? During sexual arousal, what does contraction of the bulbospongiosus muscles do?

Answer 5

1) In the superficial perineal pouch, the bulbs of the vestibule (homologous with bulb of penis) and the vestibular (ignore greater) glands are covered by the bulbospongiosus muscles
2) During sexual arousal, contraction of the bulbospongiosus expedites mucus secretion from the glands into the vestibule

Question 6

What does the fatty layer of perineal fascia cover and what does it thicken to form?

Answer 6

The fatty layer of perineal fascia that covers the superficial pouch thickens to form fatty cores of the labia majora and mons pubis

Question 7

What does midline fusion of the paramesonephric ducts form? Where does the uterine canal terminate? How does a tissue wedge form between the uterine canal and urogenital sinus?

Answer 7

1) Midline fusion of the paramesonephric ducts forms the uterine canal
2) The canal terminates at the wall of the urogenital sinus
3) Solid evaginations from the uterine canal and urogenital sinus form a tissue wedge between them

Question 8

What are the vagina and vaginal fornix formed by?

Answer 8

The vagina and vaginal fornix are formed by subsequent vacuolization of the portions of the wedge formed by the urogenital sinus and uterine canal, respectively

Question 9

What malformation creates urorectal and rectovaginal fistulas?

Answer 9

1) Rectourethral and rectovaginal fistulas may be caused by abnormalities in formation of the cloaca and/or the urorectal septum
2) For example, if the cloaca is too small, or if the urorectal septum does not extend far enough caudally, then opening of the hindgut shifts anteriorly leading to an opening of the hindgut into the urethra or vagina

Question 10

What does the exocervix protrude into and what is it surrounded by? How long is the vagina? What accounts for vagina distensibility?

Answer 10

1) The exocervix, which protrudes into the vagina, is surrounded by the vaginal fornix
2) The vagina is about 8 cm long
3) The thick lamina propria, which is filled with elastic fibers, accounts for vaginal distensibility

Question 11

What is the nonkeratinized stratified squamous epithelium of the vagina characterized by? Interpret the functional role of the pale epithelium.

Answer 11

1) The nonkeratinized stratified squamous epithelium of the vagina is characterized by pale epithelial cell cytoplasm
2) The pale epithelial cell cytoplasm is filled with glycogen, which acts as a store of energy for spermatozoa

Question 12

Where does vaginal lymph drain mainly into?

Answer 12

Vaginal lymph drains mainly into the internal iliac lymph nodes

Question 13

What conveys sensation from the superior half of the vagina? What conveys sensation from the inferior half of the vagina?

Answer 13

1) Visceral afferent fibers of the pelvic splanchnic nerves convey sensation from the superior half of the vagina
2) Somatic sensory fibers of the pudendal nerve convey sensations from its inferior half

Question 14

How does pain relief during childbirth differ after local pudendal or ilioinguinal nerve blocks?

Answer 14

1) A pudendal nerve block is going to the affect the entire perineum
2) An ilioinguinal nerve block is going to affect just the urogenital triangle