Renal/Urinary Flashcards
Path of Urine Production
Afferent/Efferent arterioles → Glomerulus → Bowmans Capsule → PCT → Descending loop of Henle → Ascending loop of Henle → DCT → collecting ducts → minor calyces → major calyces → Renal Pelvis → Ureter → Bladder → Urethra
Afferent vs Efferent capillaries
Afferent: Carry blood into glomerulus
Efferent: Capillaries that surround rest of nephron “peritubular capillaries”; where O2 transfer occurs; solutes return/leave blood stream
Urinary Output
Dependent on GFR
Glomerular Filtration Rate (GFR)
Volume of fluid filtered from kidneysglomerular capillaries to Bowmand capsule
–Balance of hydrostatic and colloid osmotic forces
per unit/time
< 80 mmHg = decreased renal blood flow/GFR
Baroreceptors
Stretch receptors are primary regulators of circulating volume
hypotension/volemia; less stretch -> reduces activity -> activation of SANS and RAAS
Converse also true; up* increase of volume = decreased Renal reabsorption = up* UOP
Antidiuretic Hormone (ADH)
Small peptide secrete by pituitary gland
Stimulated by; up* plasma osmolality + down* effective circulating volume.
Absence of ADH; renal tubular cells impermeable to H2O
ADH activated V2 receptors to open aquaporin channels to move H2O back into circulation = down* UOP
Functions of the Kidneys
1: Blood filtration/reabsorption/secretion
2: Fluid balance regulation
3: Acid-Base regulation
4: Hormone production
5: BP regulation
Micro Anatomy of Kidney
**Nephron: **responisble for filtering/reabsorption/secreting
Renal corpuscle: located in cortex (Glomerulus -> collection of capillaries; Bowmans capsule ->capsule surrounding glomerulus)
**PCT: **continuation from BC; twisted path that has increased cellular surface area exposed for filtration
Loop of Henle: descending loop similar to PCT then becomes more narrow as it ascends
DCT: continues after ascending LOH
Collecting Ducts: where DCT empties into then carry filtrate to medulla -> then calyces -> renal pelvis
