Genital Embryology Flashcards
Gonads appear in……..as a pair of……located on……
Fifth week
Longitudinal ridges, medial sides of mesonephros between it & the dorsal mesentery
Coelomic epithelium penetrate underlying mesoderm forming…….
Primary sex cords
It is impossible to differentiate between female & male gonad before….
7th week
Primordial germ cells appear……& are found in genital ridges at…….
4th week
6th week
Primordial germ cells develop from…..
Endoderm of yolk sac close to allantois
Describe mech of migration of primordial germ cells
becomes incorporated into hindgut after folding, then by ameoboid movement along doreal mesentert of hindgut to reach the genital ridges in 6th week where they become incorporated into sex cords
The gene responsible for male gonad development is…..
Testis-determining factor
……..is chct diagnostic feature of testicular developmet
Dense tunica albuginea
Describe origin of seminiferous cords
- Primordial germ cells (endoderm) give spermatogonia
- Supporting cells derived from surface epithelium (mesodermal) give Sertoli cells
Interstitial cells of Leydig develop from…….that produce…….during……whose function is…….
Mesoderm located between the cords
Testisterone (under effect of hCG)
8th wk
Masculine differentiation of mesonephric ducts & external genitalia
In fetus, Sertoli cells produce……, whose function is……
Mullerian-inhibiting factor
Suppresses development of paramesonephric ducts
Testis develops opposite……
L1
List parts of urogenital mesentery in male
- Mesotestis
- Suspensory ligament of testis (degenerates)
- Gubernacukum passes obliquely through developing ant abdominal wall to reach genital swelling
Internal descent of testis is till…..in….., while external starts at….& reaches…..at…..
Deep inguinal ring, 3rd month
7thcmonth, scrotum, 8th month
GR:
1. Internal descent of testis
2. External descent of testis
- Relative elongation of the posterior abdominal wall in upward direction without corresponding lengthening in gubernaculum.
- A) Gonadotrophins & androgens
B) Inc intra-abdominal pressure by growing viscera
C) shortening of gubernaculum due to atrophy of fibrous elements & contraction of muscular elements
Processus vaginalis is….to gubernaculum, it pushed through layers of body wall forming…..
Ventral
Inguinal canal
Undescended testis is diagnosed if it doesn’t descend to scrotum within…..
3 months
List sites of undescended are….,…..,…….
Intra-abdominal
Inguinal canal
Superficial inguinal ring
GR: Occurrence of polycystic testis
The rete testis fails to communicate with the vasa efferentia & the seminiferous tubules become distended cycts. If bilateral there is azospermia & infectility however sperms are found in testicular biopsy.
In ovarian development, primitive sex cords first form…..then form……
1ry or medullary cords
2ry or cortical cords
Describe embryological origin of primordial follicle
- Endodermal germ cells give oogonia which by active mitosis give daughter oognoia, the 2M that remain enlarge & form 1ry oocytes
- Surrounding mesodermal cells give follicular cells
Ovary reaches false pelvis in……, & true pelvis….
3rd month
After birth
If processus vaginalis persists it forms…..
Canal of Nuck
Ovarian hypoplasia is found in patients with……
44 autosomes & one X-ch (Turner’s)
Describe origin of paramesonephric ducts
A longitudinal groove appears due to in rolling of the coelomic epithelium into the underlying mesoderm, on lateral aspects of each mesonephros. The edges of the groove approach each other & fuse to form paramesonephric duct.
Cranial end of paramesonephric duct forms……
Uterine (Fallopian) tubes, Abdominal ostium & fibria develop around it
Describe fate of caudal end of paramesonephric ducts
They fuse forming Y-shaped uterovaginal canal that grows caudally & its end projects into dorsal wall of urogenital sinus forming an elevation called sinus (Mullerian) tubercle
MIF is secreted during…….., while testosterone is secretd during…..
6-7th wk
8th wk
What is fate of paranesonephric ducts in male?
Degenerates except:
1. Its cranial end forms appendix testis
2. Its caudal end forms prostatic utricle
3. Mullerian tubercle forms seminal colliculus
Caudal fused portions of paramesonephric duct form…..
Uterus & upoer 1/3 of vagina
Myometrium is derived from…..
Splanchnic mesoderm
At the site of mullerian tubercle, 2 solid evaginations called……form which fuse forming……, which completely canalizes at……
Sinovaginal bulbs, vaginal bulbs, 5th month
A thin plate known as…..separates lumen of vagina from urogenital sinus
Hymen
Mention theories of vaginal origin
- Vagina has double origin, upper one third from uterovaginal canal & rest from urogenital sinus (most recent
- Vagina is entirely derived from sino-vaginal bulbs
- Previously it was thought that paramesonephric ducts give uterus & whole vagina
Name the following anomalies:
1. Uterus has indentation
2. 2 horns with common vagina
3. Atresia of one side as an appendage to another well-developed side
4. Aplasia of one mesonephric duct
- Uterus arcuatus
- Uterus bicornis
- Uterus bicornis unicollis
- Uterus unicornis
Imperforate hymen leads to…..at puberty
Hematocolpos
In the….week, the cloacal folds are formed, which cranially form…..
A 2nd pair of elevations appear lateral called…..
3rd
Genital tubercle
Genital (labio-scrotal) swellings
In male genital tubercle forms….while in female it forms…..
Phallus (glans at distal end)
Clitoris
At end of……., both urethral folds fuse from behind forwards. Thus 1ry urethral meatus opens on……
3rd month
Undersurface of penis opposite root of the glans
During……., the definitive external urethral meatus opens at tip of glans
4th month
Epispadius is usually associated with……
Ectopia vesica
In female, urethral folds form……, labial swellings firm…., urogenital sinus opening at surface forms…..
Labia minora
Labia majora
Vaginal vestibule
In male urethra, cranial buds form….while caudal buds form…..
Prostatic glands
Bublo-urethral glands
In female urethra, cranial buds form….while caudal buds form…..
Urethral glands (of Littre)
Great vestibular glands of Bartholin
Prostatic acini are….in origin, stroma is……
Endodermal
Mesodermal
