20 Flashcards
What are homologs
organs that develop into different things
- have the same starting point in males and females
What are the homolog structures in the reproductive system
ovary – testes
round ligament – gubamaculum
Crus of clitoris – corpus cavernousum
glans clitoris – glans peins
labia majora – scrotum
What is the indifferent stage
the embryo at 5 weeks of development
- has bipotential
contains structures that can develop into the male and female reproductive structures
What are the structures of the indifferent stage
mesonephric kidney
mesonephric duct
paramesonephric duct
indfifferent gonad
What does the indifferent gonad become in XX development
cortex becomes the ovary
What does teh parameonephric duct become in XX development
oviducts
uterus
vagina
Which structures degenerate in XX developemnt
mesonephric ducts
mesonephric kidney
What does the ureter and kidneys form from
buds of the mesonephric ducts
Which organs ascend and which organs descend
kidneys and ureters ascend while the gonads descend
What does the sex-determining region of the Y chromosome do
drives male pattern developement
- SRY gene
- Testis determining factor –> stimulates sustentacular cells of the gonads
- anti-mullerian hormone –> mullerian inhibiting substnace
- parameonephric ducts regress
- SRY gene
- Testis determining factor –> interstitial endocrine cells of the gonads
- testosterone
- mesonephric ducts develop into male structures
What does the testes form from
the stroma of the indifferent gonad under the influence of testes determining factor (TDF)
What do the mesonephric ducts develop under
the influence of testosterone from the interstitial endocrine cells
What inhibits the paramesonephric ducts
MIS/AMH
which structures degenerate in the XY development
mesonephric kidney
How do the testes descend
inguinal canal opens to the abdomen and the scrotum
gubernaculum shrinks and drags testes down
pertoneum from abdomen closes over
testicular artery and vein is pulled with it
What is persistent mullerian duct syndrome
paramesonephric duct does not degenerate (b/c no AMH/MIS)
- testes are held up in the abdomen
What is the creamster muscle
moves the testes upwards
- external obliques
- skeletal muscle
What is the dartos muscle
compresses the scrotum
- smooth muscle
What is the pampiniform plexus
acts to cool blood in testicular artery
What is cryptorchidism
undescended testes
What can result from undescended testes
sterility
and
increased testicular cancer risk by 30-50x
When do testes descend
within one year
How do inguinal hernias form
portions of the small intestine herniate into the scrotum – interupts blood flow to the intestines
What are the embryological structures of the external genitalia
urethral (urogenital folds)
urethral groove - opens into the urogenital sinus
genital tubercle - rounded elevation anterior to the urethral folds
labiosacrotal swelling - paired elevated structures lateral to the urethral folds
How do the XY external genitalia develop
@ ten weeks & under the influence of the androgens
- urethral folds begin to meet and seal up
- labioscrotal swellings migrate to middle
- tip of genital tubercle becomes glans penis
- scrotum fuses at the midline (only midline raphe) is visible
- urethra sealed and opens at the tip of the penis in the glans
How do the XX external genitalia develop
near birth
- labioscrotal swellings do not fuse at midline –> stay intact as labia majora
- urogenital folds do not meet in the female and persist as vestibule and labia minora
- genital tubercle becomes the clitoris
- vagina nad urethra open into the vestibule
What are the three divisions of the male urethra/accessory glands of reproduction
seminal vesicles
prostate
bulbourethral glands
What are seminal vesicles
alkaline secretion containing clotting factors and fructose
What are prostate
secretes slightly acidic prostatic fluid that contains enzymes that break down clotting proteins
What are bulbourethral glands
alkaline secretion that neutralizes the acidic environment of the urethra and mucus to prevent sperm from sticking
What are the layers of the vagina
mucosa
- stratified, non kertinized, squamous epithelium with rugae
muscularis
inner circular and outer longitudinal layer (smooth muscle)
adventitia
What are the stabilizing structures of the uterus and ovaries
round ligament
broad ligament (double layer of parietal peritoneum)
utero-ovarian ligament
uterosacral ligament (attaches cervix)
suspensory ligament of the ovary
What are the two sizes of boney pelvises
gynecoid pelvis (XX)
android pelvis (XY)
What are features of the gynecoid pelvis
light and thin
shallow greater (false) pelvis
large, slightly oval pelvic inlet - AP ratio = 1
pubic arch > 90
sacrum shorter, wider, less curved anteriorly
wider pelvic outlet (10cm)
What are features of android pelvis
heavy and thick
deep, cup shaped greater (false) pelvis
small, heart shaped pelvic inlet - AP ratio > 1
pubic arch < 90
sacrum longer, narrower, more curved anteriorly
narrower pelvis outlet (<10cm)
