Gonadal Development Flashcards
The embryo goes through 3 attempts to form excretory ducts. What are they?
Pronephros, mesonephros, and metanephros
Is pronephros the first attempt the embryo makes? How long is its lifespan?
Yes! Short-lived & contributes pronephric duct
Is mesonephros the second attempt of the embryo to make an excretory duct? & what’s its lifespan
Yes! Its lifespan is substantial & it adopts the paranephic ducts. Becomes mesonephric duct
What is the metanephros
Adult kidney
SAME FOR MALES & FEMALES: Where do primordial germ cells populate during early embryonic development?
Yolk sac to protect them from differentiation processes. They eventually migrate back into embryo through parts of GIT
Where do primordial follicles migrate to?
From yolk sac to genital ridge which is adjacent to mesonephric kidney
Where is the genital ridge located relative to mesonephros?
Medial
MALES: at the genital ridge, coelomic epithelium develops into cell cords which penetrates
Genital ridge & take primordial germ cells with them
MALES: cell cords form
Tubules - this means inside of cell cords are invested with primordial germ cells
MALES: Primordial germ cells start to develop
Sertoli cells & germinal epithelium
In males, the seminal epithelium thickens and forms CT known as
Tunica albuginea
MALES: does the paranephric duct deteriorate>
Yes
MALES: do cell cords attach to the rete testis?
Yes
MALES: What happens when the mesonephros starts to deteriorate?
Tubules also begin to deteriorate except about 12. These provide connectivity from mesonephric duct to rete testis
MALES: The tubules change shape so that
Their origin and termination are located at the rete testis
MALES: Rete testis forms communication with
mesonephric tubules
MALES: is there a thick tunica albuginea
Yes
MALES: tubules mature into
Efferent ductules which connect to duct of epididymus
FEMALES: cell cords start to fragment and end up as
Clusters of cells in mesenchyme of genital ridge
FEMALES: primordial cells keep dividing by
Mitosis
FEMALES: Clusters of cells break down so that each cell is
A germ cell Invested with single layer of coelomic epithelium cells to eventually form granulosa cells
FEMALES; is there a thick tunica albuginea?
No
FEMALES: does mesonephric duct deteriorate/
Yes
FEMALES: does a rete ovarii develop?
Yes
FEMALES: does the rete ovarii communicate with mesonephric tubules?
No
FEMALES: do mesonephric tubules degenerate?
Yes but paramesonephric duct stays & is developed
FEMALES: the mesenchyme starts to organize around primordial follicles and contributes which cell type?
What becomes thecal cells
FEMALE:Germ cells live in which part of the gonad
Cortex
FEMALE: what part of the gonad contains the rete ovarii & is there outside communication?
Medulla & no
FEMALES: the mesovarium brings ________ to the gonad
Blood supply - exception to NO outside communication with rete ovarii as communicates through lymph
Things in gonadal development that are same in female & male
-presence of coelomic epithelium
- cell cords invade into mesenchyme
- presence of mesonephric & paramesonephric ducts
MALE: suspensory ligament of gonad comes off the
Cranial pole of gonad
MALE:The gubernaculum comes off
The caudal pole of the gonad
MALE: The gubernaculum runs from the __________ to the _________
Caudal pole of gonad through the inguinal ring
MALE: Gubernaculum function
Guides descent of testi into scrotum
FEMALE: Gubernaculum function
Kinda nothing as it does NOT provide function of guiding ovary into scrotum however, it is present
FEMALE: which species are gonads most caudal?
Ruminants <3
FEMALE: where is the proper ligament of artery located?
Gubernaculum to where uterus crosses
FEMALES: what is the round ligament of uterus & where does it go?
Remnant of gubernaculum running from uterus toward inguinal ring
FEMALE: in some cases, the round ligament of uterus goes through the
Inguinal ring. If it does, called the vaginal process
Females: can the female dog get inguinal hernias
Yes bc inguinal ring remains open
What is the shelf of tissue
Area that divides urogential tract + GIT
What do cloacal folds become
Urogenital opening after shelf of tissue divides the urogenital + GIT opening
Do males & females have cloacal folds
Yes at beginning
Do males and females have genital tubercles?
Yes
Do males & females have lateral swelling
Yes - where gubernaculum attaches
In males, lateral swellings become
Scrotum as it receives testicles
In females, lateral swellings become
Nothing they regress
In males or females is there a larger perineum development
Females
In males, genital folds fuse to form
Penile urethra & body of penis
In females, urogenital folds become
Labia of vulva
In females, the genital tubercle becomes
The clit (found it)
In males, the genital tubercle becomes the
Glans of penis
