Pathways to men and women Flashcards
Which two entirely different components can the urogenital system be divided into?
Functionally, the urogenital system can be divided into two entirely different components: the urinary system and the genital system.
What is the urinary system and the genital system developed from?
Embryologically and anatomically the urinary system and the genital system are developed from the intermediate mesoderm
Name the kidney systems
Pronephos, Mesonephros and Metanephros
Which kidney system is the genital system derived from?
Mesonephros
What happens during the fourth to seventh weeks of development?
The cloaca divides into the urogenital sinus anteriorly and the anal canal posteriorly.
What does the tip of the urorectal septum form?
The perineal body
Which parts can the urogenital sinus be distinguished in?
The upper and largest part is the urinary bladder
- Initially, the bladder is continuous with the allantois, but when the lumen of the allantois is obliterated, a thick fibrous cord, the urachus, remains and connects the apex of the bladder with the umbilicus. In the adult, it forms the median umbilical ligament
The narrow canal, the pelvic part of the urogenital sinus
- In the male it gives rise to the prostatic and membranous parts of the urethra
The phallic part of the urogenital sinus
- Development of the phallic part of the urogenital sinus differs greatly between the two seces
How are the ejaculatory ducts formed?
During differentiation of the cloaca, the caudal portions of the mesonephric ducts are absorbed into the wall of the urinary bladder. Consequently, the ureters, initially outgrowths from the mesonephric ducts, enter the bladder separately. As a result of ascent of the kidneys, the orifices of the ureters move farther cranially; thos of the mesonephric ducts move close together to enter the prostatic urethra and in the male become the ejaculatory ducts.
Which germ layer does the ureters originate from?
Mesoderm
Which germ layer does the ejaculatory ducts originate from?
Mesoderm
Which germ layer does the ejaculatory ducts originate from?
Mesoderm
Which germ layer does the ejaculatory ducts originate from?
Mesoderm
Which germ layer does the ejaculatory ducts originate from?
Mesoderm
What is the inside of the bladder lined with?
Endodermal epithelium
What does the urethra in both sexes originate from?
The epithelium of the urethra in both sexes originates in the endoderm
What is the surrounding connective and smooth muscle tissue of the urethra derived from?
Visceral mesoderm
What is the key to sexual dimorphism?
The key to sexual dimorphism is the Y chromosome, which contains the testis-determining gene called the SRY (sex-determining region on Y) gene on its short arm.
What protein does the SRY gene transcript that determines the fate of rudimentary sexual organs?
The SRY protein is the testis determining factor (TDF); under its influence, male delopment occurs; in its absense, female development is established.
When is the sex of the embryo detemined genetically?
The sex of the embryo is determined genetically at the time of fertilization
When is the sex of the embryo detemined genetically?
The sex of the embryo is determined genetically at the time of fertilization
When do gonads acquire male or female morphological characteristics?
The gonads acquire male or female morphological characteristics in the seventh week of development.
Gonads appear initially as a pair of longitudinal ridges, the genital or gonadal ridges.
They are formed by proliferation of the epithelium and a condensation of underlying mesenchyme.
Which cells have an inductive influence on development of the gonad into ovary or testis?
Primordial germ cells