Lecture 3: Development of the male reproductive system Flashcards
What do Sertoli cells do?
- Block gametogenesis
- Produce AMH (antimullerian hormone) to suppress development of Mullerian ducts
- Induce formation of LEYDIG CELLS to produce testosterone
What does Antimullerian hormone cause?
AMH causes paramesonephric ducts to degenerate
What is the tunica albuginea in scrotum?
Fascia that surrounds the gonad
What does testosterone do?
Induces mesonephric duct to form continuous duct system
Masculinizes INTERNAL male structures
What does DHT do?
Masculinizes the EXTERNAL male genitalia
What does mesonephric duct give rise to?
- Efferent ductules
- Ductus epididymis
- Ductus deferences
- Seminal gland
- Ejaculatory duct
What is the rete testis?
Anastomosing network of delicate tubules located in the hilum of the testicles
Carries sperm from seminiferous tubules to efferent ducts
Where is prostate derived? Significance?
Endoderm
Because from endoderm, it is developed under DHT (dihydrotestosterone) influences rather than testosterone
This makes sense because DHT influences external genitalia formation which is absolutely endoderm
Bulbourethral gland is also made by DHT
What enzyme converts testosterone to DHT?
Alpha reductase
What is alpha reductase?
Converts Testosterone to DHT
What is water under the bridge for males?
Ureter under ductus deferens
What is the prepuce?
Foreskin
What is the raphe of penis?
The central lining on the inferior end of penis
What happens to the urogenital folds in external male genitalia?
They will FUSE to make shaft of penis…if they don’t fuse, you have a pussy lol
What part of male reproductive system is formed from mesoderm?
- seminal vesicle
- ureter
- vas deferens
Whatever is formed from testosterone
What masculinizes external male genitalia?
DHT (dihydrotestosterone)
What is the significance of the urogenital diaphragm?
The only skeletal muscle that is used to control bladder in both women and men
Voluntary mechanism
What is tunica vaginalis?
The remnant space from processus vaginalis…space is there to allow your balls to move
Hydroceles develop here
How does testes exit abdominal cavity?
Follows gubernaculum
Very important because this allows for spermatogenesis at temperature below body temp
What is the internal spermatic fascia derived from?
Transversalis fascia
What is the cremasteric fascia derived from?
Internal oblique muscle
What is the external spermatic fascia derived from?
External oblique muscle
What is the significance of the processus vaginalis?
Space that allows balls to move up and down without friction
When does gametogenesis start in males?
During puberty
What is glans/body of penis and clit derived from?
Genital tubercle
What is labia minora/ventral penis derived from?
Urogenital folds
What is labia majora/scrotum derived from?
Labioscrotal swellings
What happens when you have no androgen receptors in fetus?
You get what looks like a female that should’ve been a male
You see bilateral inguinal hernias in the “female”
Also no menstruation…because the female only has external female structures and NOT internal female structures
XY human with female genitalia!!
What is androgen insensitivity syndrome?
A condition that results in the partial or complete inability of the cell to respond to androgens
Impairs masculinization of male genitalia
Mutation in androgen receptors
What is an adrenal cortex hyperplasia?
Excess androgens are produced and clitoris is very enlarged and then the person is intersexed
What happens when you have a defect in the alpha reductase enzyme?
You get a defect in external genitalia development
Because you need DHT to develop that shit
When you see bilateral inguinal hernias in “females” what are you thinking?
Androgen insensitivity syndrome
This person is actually XY but because of no androgen receptors, you have no male external reproductive structures
You have male reproductive structures inside but no ability to menstruate
