urinary system/fluids

• urinary system function

  maintain homeostasis of blood, volume, pressure, pH, and electrolytes. reabsorbs glucose, excretes waste. releases certain hormones like renin and EPO
• ureter

  originates near the hilum of each kidney and travels to the base of the bladder
• urethra

  allows urine to be excreted from the bladder
• renal cortex

  filtration to form urine
• renal medulla

  collects and excretes
• renal pyramids

  8 to 18 conical subdivisions within the medulla contain the kidney’s secreting apparatus and tubule
• renal columns

  lines of blood vessels and fibrous material which anchor the cortex
• renal papilla

  medullary pyramids empty urine into minor and major calyces. once in calyces its urine
• Urine drains from the major calyces into the ___ and then out through the ureter

  renal pelvis
• ureters

  transport urine from the renal pelvis of the kidneys to the bladder using peristaltic waves, hydrostatic pressure and gravity
• When volume increases, stretch receptors send signals to a micturition center in the spinal cord triggering a spinal reflex 

  micturition reflex
• urethra

  tube from the internal urethral orifice in the bladder floor to the exterior
• nephron

  is the functional unit of the kidney, blood vessels and tubules, collect filtrate from the blood and turn in into urine
• renal corpuscle consist of two structures:

  glomerular capillaries and glomerular capsule (Bowmans capsule): a double walled epithelial cup that surrounds the glomerular capillaries
• filtered fluid passes into the renal tubule, which has three main sections:

  the proximal convoluted tubule (PCT), the loop of henle, the distal convoluted tubule (DCT)
• T/F: a major function of the kidneys is to regulate blood cell size

  false
• urine leave the renal pyramids through the

  renal papilla
• correct order of kidney blood flow (arteries)

  interloper -> arcurate -> cortical radiate
• order of filtrate flow

  glomerular capsule -> PCT -> descending limb -> ascending limb -> DCT -> collecting duct -> renal papilla
• what part of the nephron makes the medulla hypertonic

  loop of henle
• renal corpuscle

  filters blood
• entry of substances into the body from the filtrate is called

  reabsorption
• what controls the pH of urine

  secretion
• what gets reabsorbed in the collecting duct

  water OR salt
• T/F: angiotensin II increases GRF in the kidneys

  false
• the kidney are

  retroperitoneal
• increased reabsorption of bicarbonate (HCO3) would result in

  an increase of pH
• increased levels of aldosterone would lead to

  increase reabsorption of sodium
• ureter

  transports urine from kidney to bladder
• which two structures make the loop of henle

  descending and ascending loops
• the process of filtration occurs in

  Bowmans capsule
• DCT empty into a

  single collecting duct
• descending limb of the loop of henle

  descends into the renal medulla
• ascending limb of the loop of henle

  turns and returns to the renal cortex, thick and thin
• cortical nephrons

  make up about 80–85% of the 1 million microscopic nephrons that comprise each kidney. Renal corpuscles far from medulla. short loops of Henle that penetrate only a small way into the medulla. ascending limbs of loops of Henle consist of only a thick segment, lacking any thin portions. receive their blood supply from peritubular capillaries that arise from efferent arterioles.
• juxtamedullary nephrons

  other 15–20% of the nephrons. Their renal corpuscles lie deep in the cortex, close to the medulla. long loops of Henle that extend into the deepest region of the medulla. The ascending limbs of loops of Henle consist of both thin and thick segments. receive their blood supply from the vasa recta that arise from peritubular capillaries 
• secretion


  selective, small amounts
• reabsorption

  selective, large amounts. most at PCT, selective reabsorption of water in collecting ducts
• filtration

  non/minimally selective, large amounts
• water reabsorbed

  purely passively