Formation of Male Repro Sys (Fields)

Fields

Primordial germ cells develop in the definitive ______ ___ at week ___-__

yolk sac 4-6

Primordial germ cells migrate from the definitive yolk sac to the ____ ___ where the testes are developing

Genital ridge

The testes develop in the

intermediate mesoderm

upper part of the urinary system, testes, and ovaries are developed from 

intermediate mesoderm

Primordial germ cells develop into _______

spermatogonia

Essential factors in the intermediate mesoderm that makes indifferent gonad

WT-1

SF-1

Lim-1

The ____ gene is Y linked. Its product is _____

SRY 

TDF (testes determining factor)

TDF

Testes determining factor

Turns indifferent gonad to testis

Sry gene product TDF

A mutation in the Sry gene will produce testes dysgenesis (defective development) and sex reversal (the individual will develop a streak gonad and female external and internal sex organs).

Swyer syndrome

Swyer syndrome 

Swyer syndrome has a uterus but no

ovaries

IVF possible

In male this gene duplication leads to over-expression of _____ protein, blocks the ____, causes Swyer phenotype (female sex organs)

DAX1

Sry gene

In makes, LOF of this gene inactivates or causes LOF of _____ gene can lead to adrenal hypoplasia, low gonadotropins, and infertility. Does NOT result in female phenotype

DAX1

In females LOF of this gene leads to adrenal hypoplasia, low gonadotropins, and delayed puberty

DAX1

_________ derived cells migrate into the intermediate mesoderm where the testes are developing and form _____ ____ around the germ cells

Peritoneum

Sex cords

Sex cord derived structures

Rete testis

Seminiferous tubules

Peritoneum forms the ___ ___ and it derived from __________ ________

Sex cord 

Splanchnic mesoderm

Sertoli cells are derived from the 

Intermediate mesoderm

Leydig cells are developed from

Fibroblasts

Approximately ____ testicular lobules in 1 testis

250

___-__ seminiferous tubules per lobule

3-4

Germ cell testicular tumor ___%

95 

Stromal cell (fibroblast and Leydig) testicular tumors ___%

1-3

Sertoli cell (sex cord) testicular tumors ____%

1.5

Types of germ cell tumors

Choriocarcinoma

Yolk Sac

Embryonal

Teratoma

Germ cell tumor in testes 

Sertoli cells produce _____, _____, _____, and ______ ______ _____

estrogen
ABP (androgen binding protein)

Inhibin

Mullerian inhibiting factor

Leydig cells produce ______

Testosterone

Estrogen produced by sertoli cells stimulates the ______ to produce _____

Hypothalamus 

Gonadotrophins from anterior pituitary 

_____ stimulates more estrogen production by Sertoli cells

FSH

_____ stimulates proliferation of spermatogonia stem cells

Estrogen

LH stimulates ______ by ______ cells

testosterone

Leydig cells

_____ stimulates more estrogen release and steroidogenesis and promotes growth of prostate, seminal vesicles, epididymis, ductus deferens, penis, scrotum, urethra 

Testosterone 

Binds and transports testosterone

ABP

After age 40, testosterone levels decrease by 1% each year. Testosterone levels below ___ ng/dl is associated with ____

300

Andropause

Responsible for male reproductive organs

Mesonephric/ Wolffian ducts

Responsible for female reproductive organs 

Paramesonephric/ Mullerian duct 

Remnants of paramesonephric/Mullerian duct

Appendix testis (hydatid of Morgagni)

Prostatic utricle (blind sac)

Appendix testis (hydatid of Morgagni) is a remnant of the

Mullerian duct

Prostatic utricle (blind sac) is a remnant of the

Mullerian duct

Mesonephric and paramesonephric ducts (Wolffian and Mullerian) develop from  

Intermediate mesoderm 

Appendix testis

remnant of Mullerian duct

Patients will usually have tenderness over the upper pole

Early torsion of the appendix testis may present with a pathognomonic “blue dot sign” (bluish discoloration seen through the scrotal skin)

Appendix testis

ASSOCIATED WITH: Downs syndrome, Hypospadias, Low Mullerian Inhibiting Factor (MIF) from Sertoli cells, Resistance to MIF

Can cause urine backup, damaging the kidney.

Enlarged prostatic utricle

Remnant of Mullerian duct

Enlarged prostatic utricle

Remnant of Mullerian duct / paramesonephric 

B

Testosterone is responsible for development of ______

Mesonephric duct/ Wolffian duct

What is formed by the Mesonephric duct?

Efferent ducts

Epididymis

Vas deferens

Seminal vesicles

Ejaculatory duct

Remnant of the Wolffian duct may present as

cysts

Epigenital tubules of mesonephric duct remnant causes

Appendix epididymis

Paragenital tubules from mesonephric duct remnant causes 

Paradidymis cysts aka Giraldis organ

Black arrow in top 

white arrow in bottom 

Appendix epididymis

remnant of wolffian duct

With volvulus (twisting). Most common cause of acute scrotal pain in prepubertal males

Appendix epididymis (remnant of wolffian duct) 

Usually have tenderness over the upper pole of the testis. Early torsion of the ______ _______may present with a pathognomonic “blue dot sign” (bluish discoloration seen through the scrotal skin).

Appendix epididymis

Paradidymal cyst (mesonephric duct remnant) 

torsion & swelling

_______ _________ with torsion & swelling. Causes a back up of fluid in the epididymis & testis.

Paradidymal cyst (mesonephric duct remnant)

Blind tube remnant from mesonephric duct

Vas aberrans

Epididymal appendix, vas aberrans, paradidymis remnant of?

Mesonephric duct / Wolffian duct

Testicular appendix, prostatic utricle remnants of?

Paramesonephric/ Mullerian duct 

Blocked efferent ducts with sperm

Spermatocele 

Spermatocele

Blocked efferent ducts. With clear fluid

Epididymal cyst

Epididymal cyst 

No connection between the efferent ducts and rete ducts.

Ectasia rete testis

Ectasia rete testis

Dilation of rete ducts & seminiferous tubules. They contain clear fluid & sperm.

Causes of Efferent Duct Blockage

Cystic fibrosis

Infections

Vasectomy

Trauma

Stones

Iatrogenic Injury (urethral manipulation)

The efferent duct is derived from the

mesonephric duct

Bacterial infection of epididymis

Epididymitis

Mesonephric duct makes

Seminal vesicle

Ejaculatory duct

Epididymis

Appendix epididymis

Epigenital and paragenital tubules

Vas deferens

efferent ductules

Peritoneum makes

Seminiferous tubules

Rete testes

Paramesonephric duct makes 

Appendix testes 

Prostatic utricle 

Summary of male structures

The genital tubercle is formed by

Lateral plate mesoderm

The genital urogenital fold is formed by

Lateral plate mesoderm

The genital swelling is formed by 

Lateral plate mesoderm 

The urethra is formed by

Endoderm

The genital tubercle (lateral plate mesoderm) forms the

shaft, glans penis, and bulb 

The genital folds/ urethral folds (lateral plate mesoderm) come together to enclose the

Urethra

The genital swellings/labioscrotal swellings (lateral plate mesoderm) comes together to form the 

scrotum 

The urogenital membrane and anal membrane is formed from

Ectoderm

Mesenchyme of the ventral shaft form the corpus ________ and the mesenchyme of the dorsal shaft form the corpus _______.

spongiosum

cavernosum

(genital tubercle lateral plate mesoderm)

The crus of the penis are attached to the _______ _____

Ischiopubic rami

The corpus spongiosum and cavernosum are developed from 

Genital tubercle 

lateral plate mesoderm 

Skeletal muscle develop from

paraxial mesoderm

Bulbospongiousus muscle and ischicavernosus muscle develop from

paraxial mesoderm

Bulbospongiosus surrounds

corpus spongiosum around bulb

Ischiocavernosus surrounds the 

Corpus cavernous around crus

Failure of genital folds to fuse ventrally 

Hypospadias 

Hypospadius is associated with

Chordee

Ventral bending of penis

Chordee

Hypospadius

Chordee

Epispadius 

Failure of the dorsal mesenchyme of the shaft (genital tubercle) to properly fuse.

Epispadias

Shortens and guides the testes into the scrotum

Gubernaculum

Mesenchymal (connective tissue) cord that originates from the genital ridge

Gubernaculum

Peritoneum forms around the anterior and lateral sides of the gubernaculum this is the 

Processus vaginalis 

Processus vaginalis is made from

Peritoneum

The proximal portion of the vaginal process undergoes _____ leaving a sac with a parietal and visceral layer anterior to the testes and epididymis.

apoptosis