Kidney And Reproductive Tract Development Flashcards
From what type of mesoderm does the urogenital tract arise?
Intermediate mesoderm
The proneohros are the first stage of kidney development and consists of 7-10 solid cell groups that regress by week…?
4
The pronephros exist in the lumbar region. T/F?
False it is in the cervical region
The mesoneohros are the second stage in kidney development. Where do these exist?
Upper thoracic and lumbar regions
The mesoneohros are the second stage in kidney development. When do these regress?
Week 8
Which oart of the mesoneohric duct induces the development of the definitive kidney?
Ureteric bud
Which part of the mesonephros will form the collecting system of the definitive kidney?
Ureteric bud
When does the metanephros appear?
Week five
When is the embryological kidney functional?
Week eleven
What two components comprise the metanephros?
Ureteric bud
Metanephric cap
What part of the metanephros forms the excretory units of the kidneys?
Metanephric cap
Nephrons continue ti be formed in the foetus until…?
Birth
What type of lining is the cloaca composed of?
Endodermal
What structure divides the cloaca into the anterior urogenital sinus and the posterior rectal/anal canal?
Urorectal septum
The bladder develops from the urogenital sinus other that which region which is instead formed by the mesonephric ducts?
Trigone region
When does the division of the cloaca by the urorectal septum occur?
Between weeks four and seven
At what point do gonads acquire male or female morphological characteristics?
Week 7
When do the genital ducts develop?
Weeks five to six
In the indifferent stage, both males and females have wollfian and mullerian ducts. Which of these ducts goes on to develop in males and which in females?
Males develop wollfian ducts
Females develop mullerian ducts
What structures do the wolffian ducts develop into under the influence of testosterone in males?
Ductus deferens
Ejaculatory ducts
Why do the wolffian ducts disappear in a female?
Lack fo testosterone
What structures do the mullerian ducts fo on to form in the female?
Uterine tubes, uterus and superior vagina
Why do the mullerian ducts not develop in males?
Sertoli cells in the testis secrte antimullerian hormone
What is the name of the ridges which the gonads initially appear as in week five in both makes and females?
Urogenital or gonadal ridges
The primordial germ cells migrate to the gonadal ridges from where?
The yolk sac
By which point must the primordial germ cells reach the gonadal ridge for development to occur?
Week six
Which master gene determines the male characteristic of a foetus?
SRY - sex determining region of the Y chromosome
Which male cells produce testosterone?
Leydig cells
SRY causes proliferation of the sex cords so that they become horse shoe shaped, filled with primitive germ cells and somatic cells and break up into tubules. What happens to these cords during puberty?
The acquire a lumen a become seminiferous tubules
Females don’t seem to have a master gene for ‘femaleness’ as seen in males but what is the closest female version of the male SRY?
Wnt 4
In week three a pair of cloacal folds develop around the cloacal membrane and join to form the genital tubercle at the cranial end. How are these folds divided caudally?
Into anterior urethra, folds and posterior anal folds
What structures do the swellings of the anterior cloacal urethral folds form in males and females?
Males are scrotum whilst females are labia majora
How do the male prostate and bulbourethral glands develop?
As outgrowths of the prostatic urethra and penile urethra
What structures does the phallus develop into in a female compared to a male?
Female clitoris
Male penis
What is bicornuate uterus?
Failure of fusion of the uterus resulting in two uteri
What is vaginal atresia?
Failed canalisation of the vagina
What is hypospadia?
Opening of male urethra is in incorrect position
Klinefelters syndrome causes lack of steroid and sperm production by leydig cells. What effect does this have?
Infertility
Gynaecomastia
Impaired sexual maturation
Describe testicular feminising syndrome
Genetic males with external female phenotype and internal testes
Produce testosterone but mutation in X chromosome causes a deficiency in the androgen receptors for testosterone sk that they cannot act on the target tissue
If a person lacks the gene for 5alpha reductase they cannot produce dihydrotestosterone from testosterone so will be genetically male but have a female phenotype with internal testes. What happens to these people during puberty?
In puberty, these people will develop a male external phenotype as pubertal changes rely on testosterone not dihydrotestosterone
Leydig cells are only present in the developing embryo until what week in development?
weeks 17-18
During development, what stimulates leading cells?
hCG
