Comparative & Developmental Reproductive Anatomy Flashcards
What 3 sources are gonads derived from?
- Mesothelium: (mesodermal epithelium) lining posterior abdominal wall
- Underlying mesenchyme: (embryonic connective tissue)
- Primordial Germ Cells: (earliest undifferentiated sex cells)
What is an indifferent gonad?
Primordial organ before differentiation into gonads
At what week are initial stages of gonadal development?
5 wk
What produces the gonadal ridge?
Proliferation of mesothelium and underlying mesenchymal cells
What is the permanent kidney primordium?
Thickened area of mesothelium developing on medial side of mesonephros
Indifferent gonad consists of
External cortex
Internal medulla
Cortex differentiates into
Ovary, medulla regresses
Indifferent gonad:
Medulla differentiates into
Testes, cortex regresses
What do the Gonadal cords become in males at wk5?
Seminiferous cords (Primordia of the seminiferous tubules)
What do the parts of the gonadal cords that enter the medulla become in wk 5?
Rete Testes
What 2 kinds of cells are made during wk 5 male sexual differentiation in gonads?
Spermatogonia And Sertoli Cells
What are spermatogonia derived from?
Primordial germ cells
What are sertoli cells derived from?
Mesenchyme
What are follicular cells derived from?
Surface epithelium of ovary
Which duct is the paramesonephric duct?
Mullerian
Which duct is the mesonephric duct?
Wolffian
In male embryo, SRY turns on expression of…
Testis determining factor
What cells make Anti-Mulerian Hormone?
Sertoli Cells
Wolffian duct becomes the …
Conductive ducts: epididymis, vas deferens, seminal vesicles
Where are PCGs initially located?
Amongst endodermal cells of yolk sac, near origin of allantois
PCGs migrate along…
Dorsal mesentery of hindgut to gonadal ridges
What is happenening to PGCs during 6th week of development?
PGCs enter underlying mesenchyme and incorporated into gonadal cords.
The Homologous Genital tubercle differnetiates into:
Penis (male), Clitoris (female)
The urethral folds develop into the:
Penile urethra (male), labia minora (female)
The urethral groove deveops into the:
Disappears in males, Vestibule (Females)
The labioscrotal swelling develops into the:
Scrotum (male), Labia majora (female)
What directs direction of descent of ovaries and testes?
Gubernaculum
Why does the testes descend into the scrotum?
Temperature regulation for sperm production
What happens to the gubernaculum in males?
Shrinks into a small structure attached to the base of the scrotum
What happens to the gubernaculum in women?
Gives rise to the ovarian and round ligaments, the latter is attached to the labia majora
The male pelvic cavity shown no reprductive organs between the urinary bladder and the rectum except for the…
Seminal Vesicles
Length of male urethra :
18-24cm
Length of female urethra
3-5cm
In females, the urethral sphincter…
Extendsright through the pelvic diaphragm to the neck of the bladder
In males the urethral sphincter…
also extends through the pelvic diaphragm, but stops at the base of the prostate
Where does the pudendal nerve arise from?
Sacral spinal nerve plexus
What do the sensory nerve branches of the pudendal nerve supply?
Lower anus, perineum, and external genitalia
What do the motor nerve branches of the pudendal nerve supply?
Anal sphincter, small perineal muscles including the urethral sphincter, the pelvic diaphragm.
Where does the autonomic nervouse supply pass through to get to the genitalia?
Directly from the interior of the pelvis to the pelvic diaphragm
Where does the sympathetic innervation to the genitalia arise from?
Lower thoracic / Upper lumbar
Where does the parasympathetic innervation to the genitalia arise from?
Sacral S2-4
Where do the testes and parts of the scrotum recieve their nerve supply from? Why?
Recieve nerve supplies directly from the lumbar levels and pelvic autonomic plexi via spermatic cord. Due to testes descending dragging diffrerent nerves w/ them. (Parts of labia majora supplied in similar way.)
Describe the blood supply to the genitalia
Homologous in both sexes:
Common Iliac branches into internal and external iliac. Femoral branches off external iliac and pudendal branches off internal iliac
Compare the male pelvis to the female pelvis
- More heart shaped,
- Greater anterior-posterior rather than lateral dimensions
- Has more vertical iliac crests
- More acute infrapubic angle
- Inward directed ischial spines, sacrum and coccyx
