Reproductive: Anatomy and Development Flashcards
Gonads differentiate into what in male and female?
male: testes, semineiferous tubules, rete testes
female: ovary, follicles, rete ovarii
Male and female: paramesonephric ducts differentiate into what?
Male: appendix of testes
female: uterine tubbes, uterus, cervix, upper vagina
Mesonephric ducts differentiation
Male: epididymis, ductus deferens, seminal vesicle, ejaculatory duct
Female: Duct of gartner
Phallus differentiation
Male: glans and body of penis
Female: clitoris
urogenital folds differentiation
Male: ventral aspect of penis
Female: labia minora
Labioscrotal swellings differentiation
Male: scrotum
Female: Labia majora
What is the most common cause of female pseudointersexuality?
congenital adrenal hyperplasia => fetus produces excess androgens
What is the most common cause male pseudointersexuality?
5a-reductase deficiency causes inadequate production of testosterone and MIF by fetal testes
What does female pseudointersexuality look like grossly?
ovarian (but no testicular) tissue;
masculinization of female external genitalia
What does the male pseudointersexuality look like grossly?
testicular (not ovarian) tissue and stunted development of male external genitalia
What is the result of a 5a-reductase 2 gene mutation?
5a-reductase enzyme is underactive in catalyzing conversion of testosterone to DHT
What are the clinical findings of 5a-reductase 2 deficiency?
underdevelopment of penis/scrotum and prostate gland => microphallus, hypospadias, bifid scrotum
What happens in complete androgen insensitivity?
occurs when fetus w/ 46, XY develops testes and female external genitalia w/ rudimentary vagina => uterus/tubes are generally absent
Where are the testes located in complete androgen insensitivity?
found in labia majora => surgically removed to circumvent malignant tumor formation
What is the most common cause of complete androgen insensitivity?
mutation in androgen receptor (AR) gene rendering AR inactive
What is the gross phenotype of complete androgen insensitivity?
normal appearing females and psychosocial orientation is female despite phenotype
What causes a female with complete androgen insensitivity to go to the physician?
at puberty, undergo virilization due to increased T:DHT ratio
What forms the floor of the pelvis?
pelvic diaphragm (2 layers of fascia with middle layer of muscle)
What are the muscles that make up the pelvic diaphragm’s middle layer?
levator ani and coccygeus
What is the action of the levator ani?
muscular sling for rectum;
boundary between rectum and anal canal
What does the region below the pelvic diaphragm contain?
perineum contains the ischioanal fossa
What does the ischioanal fossa contain?
fat filled region below pelvic diaphragm surrounding anal canal
Where is the urogenital diaphragm? composed of what?
perineum and extends between the 2 ischiopubic rami;
2 layers of fascia w/ middle layer of skeletal muscle
What is the deep perineal pouch?
middle (muscle) layer of the urogenital diaphragm
What can be found in the deep perineal pouch?
sphincter urethrae muscle;
deep transverse perineal muscle;
Bulbourethral (Cowper) gland (male only)
Action of sphincter urethrae muscle
serves as external sphincter of urethra
Describe the bulbourethral gland
duct that enters the bulbar urethra
What is the superficial perineal pouch?
below UG diaphragm and enclosed by superficial perineal colles fascia
What does the superficial perineal pouch contain?
crura of penis or clitoris;
bulb of penis (male) or bulb of vestibule (female);
Ischiocavernosus muscle;
bulbospongiosus muscle;
greater vestibular (Bartholin) gland (female)
What is the function of the crura of penis/clitoris?
erectile tissue
function of bulb of penis
erectile tissue; contains urethra
function of vestibule
erectile tissue; lateral walls of vestibule
function of ischiocavernosus muscle
skeletal muscle that covers crura of penis/clitoris
function of bulbospongiosus muscle
skeletal muscle that covers bulb of penis/vestible
function of vestibular (Bartholin) gland
homologous to Cowper gland
What innervates the skeletal muscles in pelvic and UG diaphragms?
Pudendal nerve and branches (S2, S3, S4 ventral rami)
What does the pudendal nerve innervate within the pelvic and UG diaphragm?
external anal sphincter;
sphincter urethrae;
skeletal muscles in both perineal pouches;
skin that overlies perineum
