Urinary System Flashcards
What are the four main components of the urinary system and from which germ layer does each derive?
Kidneys (mesoderm), Ureters (mesoderm), Urinary bladder (endoderm), Urethra (endoderm)
Name the three kidney sets seen during development and when each appears
Pronephros (4th week, is vestigeal), Mesonephros (later in 4th week, is interim kidney), Metanephros (5th week, is true kidney)
What does the mesonephros end up becoming in males?
Epididymis and vas deferens
Give the relationships of the three primordial kidney systems
Pronephros rostral to mesonephros rostral to metanephros (i.e. pro is most rostral, meta is most caudal)
What do the mesonephric ducts terminate into and what do they become in the adult?
Terminate into cloaca, become genital ducts in males
What structures does the genital ridge develop into in males and females respectively, and how far into development is this ridge the same in the two sexes?
Testes in men, ovaries in women. Ridge is same in both until week 6
What are the two developmental sources of the metanephroi (permanent kidneys) and what is the function of each?
Ureteric bud (collection) and Metanephric blastema (urine production)
The ureteric bud is an outgrowth of what structure and initially connects what to what?
Outgrowth of mesonephric duct, initially connects metanephric blastema to cloaca
How do the ureteric bud and metanephric blastema influence each other developmentally?
Through reciprocal induction (they induce each other to develop into the correct structure)
What cell signaling factor is important in reciprocal signaling in the developing kidney, what condition to this lead to, and how does it present?
WT1, Wilms tumor (of the kidney), presents as mass over kidney region
Give the levels of the kidney collecting system in order
Collecting tubules, Minor calyx, Major Calyx, Renal pelvis
Name the parts of the nephron in order and what they are derived from
Renal corpuscle (consists of glomerulus and bowmans capsule), Proximal Convoluted Tubule, Loop of Henle, Distal Convoluted Tubule. They are derived from metanephric blastema
What is the function of the prenatal kidney?
Supplementing amniotic fluid. Urine production is not the primary function until after birth
Describe the positional change that occurs for the kidneys, mesonephrons and gonads during development
The mesonephros/gonads descend (along with the rest of the body) and the kidneys ascend along the posterior abdominal wall
What happens to the kidneys and their arterial supply as the ascend during development?
They rotate medially, new arterial supplies are formed and old ones degenerate
What are pelvic and horseshoe kidneys and why do they occur?
One (pelvic) or both (horseshoe) kidneys remaining in the pelvic area. Caused by a failure of the kidneys to ascend and medially rotate during development (weeks 6-9)
What does the cloaca become?
The urogenital sinus (which becomes bladder and uretrha) and rectum
Urinary trigone
A patch of mesoderm integrated into the bladder wall where it meets the ureter
What is the origin of the epithelium, and inner wall muscle respectively, in the bladder?
Epithelium on inner surface is endodermal, muscle is mesodermal
What is the median umbilical ligament a derivative of?
The urachus, which is a fibrous cord that is remnant of the allantois
The trigone of the bladder is formed as what two structures intercalcate into the bladder?
The ureteric bud (becoming the ureter) and the mesonephric duct)
What might cause leakage of urine between the bladder and the umbilicus?
A patent urachus (fistula) with a urachal sinus. A remaining urachus would connect the bladder to the umbilicus
