Flashcards in Embroylogy Of The Urianary System Deck (26)
Where do the kidney systems form from?
The intermediate mesoderm
What are the 3 stages of the development of the kidney?
Pronephros, mesonephros and metanephros
When does the pronephros develop?
Forms at the start of the 4th week, and has disappeared again by the end of the 4th week
What are some of the features of the pronephros?
Never functions in humans and is described as a duct, which extends from the cervical region to the cloaca and drives the next developmental stage
What is the urogenital ridge?
A region of intermediate mesoderm giving rise to both the embroyonic kidney and the gonad
What are some of the features of the mesonephros?
It is formed in the pronephric region, is derived from the intermediate mesoderm in the upper thoracic and lumbar regions, and appears in the 4 th week of development during the regression of the pronephric system
How does the mesonephros develop?
Lengthens rapidly, forms a s shaped loop and aquires a tuft of capilleires that will form the glomerulus at their medial extremity and around the golomeukus the tubules in the bowman's capulse and therefore the renal corpuscle
What happens in the mesonephric duct?
Sprouts the urogentital bud which induces the development of the definitive kidney, and has an important role in the development of the reproductive system.
What are some of the features of the metanephros?
The utreic bud induces the development of the definitive kidney within the intermediate mesoderm of the caudal region of the embryo,p.
What is the uteric bud?
Is an outgrowth of the mesonephric duct close to the entrance of the cloaca
What happens to the uteric bud?
The bud penetrate the metanephric tissue, Nd divides to form the primitive renal pelicis, and forms tubules which form the calcyes of the kidney, and this gives rise to the ureter, the renal pelvis and the major and minor calcyes
What is the importance of the uteric bud?
The uteric bud drives the development of the definitive kidney, and the excerterory component is derived from the intermediate mesoderm under the influence of the uteric bud
What is the ascent of the kidney?
The metapnepheic kidney first appears in the pelvic region, and undergoes an apparent caudal to cranial shift and crosses the atreial fork formed by the vessels returning blood from the featus to the placenta
What causes the ascent of the kidney?
It is caused by a dimmunation of the body curvature and by the growth of the body in the lumbar and the sacral regions,
What happens to the blood supply of the kidney during its ascent?
In the pelvis the metanephros receives its blood supply from a pelvic branch of the aorta, and during its ascent to the abdominal level, it is vascularised by ateries that originate form the aorta at continously higher levels, and the lower vessels commonly degenerate .
What can go wrong in these processes?
Utreic bud fails to interact with the intermediate mesoderm, migration goes awry, wilms tumour, duplication defects, an ectopic ureter and cyctic disease
What is a wilms tumour?
A cancer of the kidney which commonly affects children to five years of age due to mutations and is commonly associated with other conditions
What causes duplication defects and ectopic uretheral defects?
Splitting of the utreic bud, partial or complete and the symptomatic consequence is the ectopic urethral opening
What are the different types of cystic kidney disease?
Multicystic kidney disease involves atresia of the ureter and there is polycystic kidney disease is recessive and presents early and and therefore has a poor progonisis
What is the cloaca?
Early in development, the gastrointentaisl urianry and reproductive ducts end at a single structure that is known as the cloaca
What is the urogential sinus?
This is created from the hindgut from the urorectal septum, and is conintiojs with the umbilicus due to the uracus and the median umbilical ligament
What does the cloaca divide into?
The urogential sinus anteriorly and the anal canal posteriorly
What is the urorectal septum?
Is a layer of mesodem between the anal canal and the urogential sinus
What is the urogenital sinus divided into ?
The largest upper part is the future bladder, and the pelvic and the phallic part are the parts of the future urethra
What does the pelvic part give rise to in males?
This gives rise to the protastaic and membranous parts of the urethra, phallic part will be pulled as it rises