Renal System

Front 1

What are the functions of the kidney

Back 1

1) remove waste, urea and toxins
2) Maintain acid/base balance (active excretion of H+, reabsorption of bicarb, NH3 production)
3) Maintain BP (RAS)
4) Maintain blood oxygen carrying capacity (EPO)
5) Convert vitamin D to calcitriol (calcium homeostasis)
6) Maintain electolyte levels

Front 2

Describe the steps of tubular autoregulation if MAP falls

Back 2

1) Decreased MAP -> decreased tubular flow and increased Na+ reabsorption
2) Macula densa cells at distal tubule detect lower conc of Na+ in filtrate
3) Juxtaglomerular cells secrete renin into bloodstream
4) Angiotensin II constricts eferent arteriole causing increased GFR, restoring flow

Front 3

Describe the origin of the urogenital system

Back 3

1) Kidney and ureters from intermediate mesoderm
2) Bladder and urethra from the the urogenital sinus

Front 4

Describe the development of the mesonephros starting at the cervical region

Back 4

1) cervical nephrotomes segment at 24 days
2) segmentation progresses down the strip of intermediate mesoderm caudally forming the mesonephros draining into the mesonephric duct.
3) cervical nephrotomes degenerate as lumbar ones form at 26 days

Front 5

Describe the formation of the embryonic rectum, perineum and allantois

Back 5

1) The cloaca forms a sinus between the allantois (bladder) and hindgut
2) The cloaca is divided by the urogenital septum
3) The anterior portion develops into the definitive urogenital sinus (bladder, prostatic urethra, penile urethra) in the pelvic region and the allantois in the abdomen next to the umbilicus

Front 6

Describe the blood supply to the embryonic mesonephros and associated structures

Back 6

1) Paired aorta extend blood vessels along the length of the intermediate mesoderm to supply embryonic glomeruli
2) The mesonephros forms embryonic Bowman's capsules collecting filtrate

Front 7

Describe the embryonic formation of the trigone

Back 7

1) The ureteric bud joined to the mesonephric duct develops and the pair moves into the bladder wall
2) The ureteric buds and the mesonephric ducts separate olong the bladder forming the trigone
3) The 2 mesonephric ducts forms the vas deferens joining at the apex of the trigone with the ureters on each corner of the base.

Front 8

Describe the time frame of the development of the final kidneys and explain why lobulated kidneys may be present at birthh

Back 8

1) At 4 weeks kidney lobules form around each developing branch of the ureteric bud
2) By 16 weeks, a lobulated kidney forms which may be present at birth

Front 9

Explain how each kidney can have up to 3 renal arteries

Back 9

As the kidneys ascend from the pelvis, the blood supply changes along the length of the aorta. If the remnant artery does not degenerate, it can remain at birth.

Front 10

Describe the variations in kidney shape and location caused by problems ascending from the pelvis

Back 10

1) One or two pelvic kidneys may arise
2) A single horseshoe kidney may arise because of fusion of close proximity kidneys then getting trapped under one of the abdominal arteries (eg inferior mesenteric)

Front 11

Describe the embryonic formation of the major calyces

Back 11

1) At 6 weeks, 4x binary divisions of the ureteric bud occurred
2) These degenerrate into the major calyces, leaving sufficient buds dividing distally to form the final drainage structures.

Front 12

What is the embryological origin of the non-collecting duct portion of the nephron

Back 12

The metanephric blastema forms the Bowman's capsule, proximal and distal tubules and LOH