What are the parts and functions of the urinary system?

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Study guide

• What are the parts and functions of the urinary
  system?
• What is the macroscopic and microscopic structure
  of the kidney?
• What are the 3 processes in urine formation?
• How is the kidney involved with regulating
  water-salt balance of blood?
• What are the common disorders of the kidney?

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Overview of the urinary system
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What are the functions of the urinary system?

• Excretion of metabolic wastes
• Maintenance of water-salt balance
• Maintenance of acid-base balance
• Hormone secretion

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1. Excretion

• Mostly of nitrogenous wastes
• __________ made by the breakdown of amino acids
  in the liver
• _________________made by the breakdown of
  nucleotides (What? Do I eat DNA?)
• Creatinine made by ___________________from the
  breakdown of creatine phosphate

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2 3. Maintenance of water-salt and acid-base
balance

• Both are homeostatic mechanisms
• Water-salt balance helps to maintain blood
  pressure
• How does blood pH change when there is an excess
  of hydrogen ions?

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4. Hormone secretion

• Renin secreted by the kidneys to allow the
  adrenal glands to secrete aldosterone to help
  regulate water-salt balance
• ___________________ secreted by the kidneys to
  stimulate red blood cell production when blood
  oxygen is low

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What are the 3 regions of the kidney?

• Renal cortex an outer granulated layer
• Renal medulla cone-shaped tissue masses called
  renal pyramids
• Renal pelvis central cavity that is continuous
  with the ureter

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What are nephrons?

• Microscopic functional unit of the kidney that
  produces urine

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Tubules of nephron

• Function
• Filter fluid and reabsorb needed substances
• Structures
• Proximal convoluted tubule
• Loop of Henle
• Distal convoluted tubule
• Collecting duct

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Blood vessels associated with tubules

• Arterioles
• Afferent
• Efferent
• Capillaries
• Glomerular
• Peritubular
• Vasa recta

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How does the nephron form urine?
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Glomerular filtration

• Based on size alone
• What components are too big to pass?

• Proteins
• Formed elements
• Ions
• Amino acids
• Glucose
• Urea
• Salts
• Water
• Drugs poisons

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Tubular reabsorption and secretion

• Which molecules would we want to reabsorb and
  keep in the body? Which ones secreted?

• I
• Ions
• Amino acids
• Glucose
• Urea
• Salts
• Water
• Drugs poisons

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What happens when you have been sweating or have
eaten a salty meal?

• Where are the osmoreceptors?
• What is the control center?
• What hormone is released by the pituitary?
• What is the effector?

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Water reabsorption in nephrons
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What role does alcohol play in this process?

• Alcohol inhibits ADH secretion
• What happens to urine output?
• How does this affect water levels in body?

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Kidney function disorders

• Diabetes, hypertension and inherited conditions
  are the most common cause of renal disease and
  failure such as
• Hematuria
• UTI
• Pyelonephritis
• Kidney stones hard granules formed in the renal
  pelvis due to UTIs, enlarged prostate, pH
  imbalances or intake of too much calcium

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How can kidney failure be treated?

• Hemodialysis uses an artificial kidney machine
  to subtract and add substances to the blood as
  needed
• Continuous ambulatory peritoneal dialysis (CAPD)
  used the peritoneum to filter the blood
• What is the peritoneum?
• Kidney replacement single kidney transplant
  with a high success rate, but relies on a donor