Question | Answer |
What both the urinary and genital systems arise from ? | * Intermediate Mesoderm |
The excretory tubules formed by ? | * the mesonephros --> mesonephric (wolffian) duct (in males, some pieces remain, and in women, it completely go away) |
What is the structure that is medial to the two mesonephros ? (in between them) | * the urogenital ridge |
The metonephros forms ? | * adult kidney ....... * |
Comes off of the mesonephros to attach to the metonephros ? | * ureteric bud, and the metonephric tissue grows around it |
What the ureteric bud then does ? | * expands to make the renal pelvis, later making the maj/min. calyces, and collecting tubules |
Congenital anomalies of the ureter ? | * the ureteric bud will begin splitting early and we see either a bifid ureter or a double ureter |
Happens when the cloaca divides ? | * urogenital sinus anteriorly, and the anorectal canal posteriorly...... * in between these two, the urorectal mesdoerm develops (is mesoderm) |
Divisions of the urogenital sinuses ? | * Largest portion = bladder..... * Intermediate Portion = prostatic and membranous urethras and prostate in Men....Makes the urethral and paraurethral glands in women...... * Final Part = phallic |
The bladder is continuous with ? | * allantois --> forms the urachus --> median umbilical ligament in adults |
When a localized portion of the lumen persists ? When only the upper portion of the lumen persists ? | * urachal cyst..... * urachal sinus |
Congenital abnormalities of the bladder, due to the body wall not closing properly ? | *If incomplete closure occurs in the pelvic region, bladder exstrophy can occur (ventral abdomen has the bladder exposed)...... * in males we also see epispadias in this condition |
Exstrophy-epispadias complex ? | * A severe defect in body wall closure will include epispadias, bladder exstrophy, and cloacal exstrophy. ... * in less severe, we may only see one issue of those 3 |
So what actually causes the body wall defect that leads to exstrophy? | * with the development and rupturing of the cloacal membrane..... * Normally, the ventral aspect of the cloaca is composed of a layer of endoderm and ectoderm called the cloacal membrane |
continued... | *Exstrophy is thought to occur when the cloacal membrane becomes overdeveloped and prevents tissue from migrating medially during formation and closure of the ventral body wall. |
Development of the gonads ? | * develop in the urogenital ridge that is in between the mesonephros..... * then the germ cells migrate to urogenital ridge to develop the gonad |
Development of the testes ? | * SRY gene encodes the testis determining factor --> testis (medullary) cords developing --> rete testis |
Leydig and Sertoli Cells ? | * sustentacular (Sertoli) cells that are derived from the surface epithelium. Interstitial (Leydig) cells are derived from the original mesenchyme and are located between the testis cords... * Week 8 make Test and cause sexual differentiation |
Testis and puberty ? | * The testis cords remain as cords (i.e., solid strands) until puberty when they develop and lumen and become seminiferous tubules. |
Development of ovaries ? | * if No SRY gene, the sex cords develop unorganized in to cortical cords.... * 3rd month = cortical cord splits to surround the primordial oocye with a layer of follicular cells to make the primordial follicle |
Both males and females initially have two pairs of genital ducts called ? | * mesonephric (wolffian) ducts and paramesonephric (mullerian) ducts |
Happens to the paramesonephric duct ? | * fuse and project in to the urogenital sinus and make the paramesonephric tubercle |
Male duct development ? | * Under the influence of the SRY gene, the paramesonephric ducts degenerate following secretion of anti-Mullerian hormone (AMH).... * Mesonephros that remains to form the efferent ducts, epididymis, ductus defrens, and seminal vessicle, and ejac duct |
Female duct development ? | * the paramesonephric ducts develop into the main genital ducts through influence of estrogens and the WNT4 gene.... * they fuse to make the body of the uterus, cervix, and upper part of the vagina |
Development of the vagina ? | * After the tip of the uterine canal reaches the urogenital sinus, the sinovaginal bulbs form and develop into a solid vaginal plate and progressively elongate... * upper flares make the fornices |
Forms what in vaginal development ? | * The fornices and upper portion of the vagina are formed from the uterine canal (paramesonephric ducts) whereas the lower part is formed by the urogenital sinus. |
Formation of external genitalia | * mesenchymal cells migrate to the area around the cloacal membrane to form a paired set of cloacal folds....* forms the genital tubercle, urethral folds, anal folds, & genital swellings develop on sides of cloacal folds --> scrotal swellings or lab. maj |
Male external genitalia ? | * genital tubercle grows rapidly and becomes the phallus ( head ).... * urethral folds combine to make the shaft and urethral groove (penile urethra)..... * scrotal swellings = scrotum...*ectoderm migrates in to form/open ext. urethral meatus |
Female external genitalia ? | * genital tubercle = clit..... * urethral folds do not fuse = lab. minora ...... * Genital Swellings = lab. majora |
Congenital anomalies of the penis ? | * hypospadias = incomplete fusing of the urethral folds ....... * Epispadias = an abnormal opening of the urethra on the dorsal aspect of the penis, and is an anomaly is part of the exstrophy-epispadias complex (defect in ventral body wall closure) |
Descent of the testes ? | * initially attached to the abdominal wall.... * after the mesonephros degens., we get the caudal genital lig and the gubernaculum....* the gub. grows towards the scrotal swellings and the process vaginalis follows the gub. |
After the gubernaculum reaches the scrotal floor ? | * pulls the testes through the inguinal canal, over the pubic bone, while taking the blood supply from the abdominal aorta with it |
The process vaginalis forms ? | * reflects and forms an inner visceral layer of the tunica vaginalis and an out parietal layer of the tunica vaginalis |
Muscles/Layers that the testes do not descend through to go to the scrotum ? | * the transversus abdominis muscle |
Layer order as it passes from stomach to scrotum ? | * from innermost to outer most = transversalis fascia - internal abdominal oblique - ext. abdominal oblique |
Congenital anomalies of testicular descent ? | * cryptorchidism = when one or both of the testes fail to descend |
Issue if the process vaginals does not fully close, separating the abdominal cavity with the scrotum ? | * completely open pathway, the intestines can easily pass through the opening, forming an indirect (congenital) inguinal hernia...... * partially closed, a cyst may develop, leading to a hyrdocele of the testis or spermatic cord |
Descent of the ovaries ? | * The cranial genital ligament, forms the suspensory ligaments of the ovaries...... * The gubernaculum is present, but remains in the inguinal canal to form the round ligament of the uterus and the ovarian ligament. |