L19: Development Of The Urogenital System Flashcards
What are the 3 parts of the male urethra
Prostatic urethra
Membranous urethra
Spongy urethra
Which duct connects to the prostatic urehtra
- Ejaculatory duct (connection of the seminal vesicle and vas deferens)
- bladder
When the mesoderm forms which 3 parts are there
Somatic lateral plate mesoderm
Paraxial mesoderm
Intermediate mesoderm
Which 2 components arise form the intermediate mesoderm
Urinary system
Genital system
When the embryo begins to fold what happens to the intermediate mesoderm
Bulges into the peritoneal cavity known as intra embryonic coelum and gives rise to the urogenital rusge
When the urogenital ridge forms what are the 2 parts of it
Gonadal ridge
Nephrogenic cord
What does the gonadal ridge contain
Gonad
What does the nephrogenic cord contain
Paramesonephric duct
Mesonephric duct
What does the paramesonephric duct form
The female duct system
What does the mesonephric duct form
The male duct system
Where does the kidney derive from
Nephrogenic cord
What are the 3 staged of kidney evolution
Pronephros
Mesonephros
Metanephros
What is the pronephros
The most primitive kidney that develops in the cervical region which disappeares
What is the mesonephros
Functioning kidney in most anomiates located in the thoroacolumbar region
In humans it then disappears and ductus from the male genital duct - mesonephric duct
What is the metanephros
The functioning kindey of most amniates and in humans located in the sacral region
What does the mesonephric duct form so it can connect to the mesonephric blastema
Uteric bud
What does metanephric blastema form
The nephrogenic cord that from the kidney
When the uteric bud penetrates to the metanephric blastema what does it form
The major calyx
Minor calyx
Ureter
What does the metanephric blastema form
The other layers of the collecting tubules
What happens to the Kidney when it forms in the sacral region
Ascends up
What happens to the pronephros and mesonephros
Disappear
What forms the ureters
Uteric bud
When the endoderm fold during folding what structure does it form that gives rise to the bladder and the urethra
Cloca
What are the 2 parts of the cloca
Anterior part
Posterior part
What does the anterior part form
Bladder and urethra
What does the posterior part of the cloca form
The primitive rectum
In males what happens to the mesonephric duct when the bladder forms
Gets absorbed into the wall of the bladder which will become the ducts deferens in the future
At the neck of the bladder what forms to give rise to the prostate gland
New buds
Which structure forms the posterior wall of prostatic turban
Mesonephric duct
What is the tip of male urethra that opens to the outside derived from
The endoderm
Which gene in the Y chromosome allows the development of the testis
SRY gene
In females what does the absence of SRY gene cause
Expression of NNT4 that differentiates gonads into ovaries
Describe the process that occurs to from the testis
1) coelimic epithelium form primary sex cords which develop into future seminiferous tubules where PCGS are
2) mesonephric duct forms the rete testis
3) the remaining layer of tunica albuginea divides the testis into lobules that contain the seminiferous tubules
Describe the process that occurs in ovary development
1) coelimic epithelium cells do not penetrate deeply to the medullary mesenchyme to form the primordial follicles
2) PCGS are located within the primordial follicles
3) Müllerian duct forms into the uterine tube
Which cells in the testis produce testosterone
Leydig cells
What are the 2 rings of the inguinal canal
Deep inguinal ring
Superficial inguinal ring
Describe how the inguinal canal is formed as the testis descends
1) the gubernaculum that is attached to the base of the scrotum shortens
2) this forms a small pouch of the peritoneum called the processes vaginalis
3) as the gubernaculum contracts is brings the layers of the abdominal wall
4) internal oblique muscle become the cremasteric fascia that contains the cremasteric muscle
5) external oblique muscle becomes the external spermatic fascia
6) transversal is fascia become the internal spermatic fascia
7) processes vaginalis i.e parietal peritoneum becomes the tunica vaginalis
8) the gubernaculum remnant becomes the ligament of the scrotum
In females what is the descent of the ovaries too far prevented by
The developing uterus
What are the remnants of the gubernaculum in females
Ligament of ovary
Round ligament of uterus
Which ligament passes the inguinal canal in females
Ligament of the uterus
What is undescended testis called
Crytochoidism
What is the difference between cyptochoidism and ectopic testis
Cryptochoidism- undescended testis along the initial descending pathway
Ectopic testis - testis can occur anywhere form the abdominal to the groin region
What is the complications/risks of cryptochoidism
Increased risk of testicular torsion
Inguinal hernia
Decreased fertility
Increased risk of testicular cancer
What hormone does the developing testis and the Sertoli cells cells secrete
Anti mullerian hormone
What does the anti mullerian hormone cause
Regression of the Müllerian duct (female duct) and formation of the wolffian duct
What structures does the wolffian duct form
Epididymis
Vas deferens
Seminal vesicle
Ejaculatory duct
What happens in males to allow the Müllerian duct to develop
Oestrogen is produced which regresses the wolffian duct and develops the Müllerian duct
What structures does the Müllerian duct give rise to
Fallopian tubes
Uterus
Proximal 1/3rd of the vagina
Where is the wolffian duct derived from
The mesonephric duct - where the kidney develops from
In females what is the Müllerian duct derived from
The paramesonephric ducts
In females what forms the lower 2/3rd of the vagina
Endoderm
When the paramesonephric ducts cross medially, they drag a fold of peritoneum which fuse together, what does this peritoneum form
The broad ligament
In the embryo external genitalia what are the structures that are present
Genital tubercle
Genital swelling
Genital folds
What structure does the genital tubercule form in the males
Glans penis
What structure does the genital tubercle form in females
Clitoris
What structure does the genital fold form in males
Penis shaft
What structure does the genital folds form in females
Labia minus
What structure does the genital swelling form in the males
Scrotum
What structure does the genital swelling form in females
Labia majora
What is hypospadias
When the genital folds failure to fuse together along the undersurface of the shat of the penis that leads to abnormal urethral orifices
If the urethra opens at the dorsal surface of the penis what is this known as
Epispodias
