Excretory System

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Excretory System

• Urine Good Hands

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The Excretory System

• The Structures Involved
• Kidneys,
• ureter,
• bladder,
• urethra, etc.

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The Excretory System

• AKA The Urinary System
• Purpose
• to eliminate waste products (urea) or unneeded
  substances from the body
• Ex (do not write)
• The breakdown of proteins leaves the amine group
  (NH2-) unused. It is converted to ammonia (NH3)
  in the liver, which is extremely toxic, and then
  urea (NH22CO2) which is less toxic. Blood
  carries urea to the kidneys for elimination!

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The Kidney Urine Formation

• 4 Phases
• Filtration
• Reabsorption
• Secretion
• Excretion

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The Kidney Urine Formation

• Filtration
• Renal arteries bring blood to the kidneys
• Blood travels to a nephron which is surrounded by
  capillaries
• Fluids to be processed
  enter Bowmans Capsule from
  blood (120 ml each min.) (Blood
  cells cannot pass through)

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The Kidney Urine Formation
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The Kidney Urine Formation

• Reabsorption
• Occurs in the Loop of Henle ? 119 ml returned
  to the blood, 1 ml becomes urine (urine 95
  water, 5 urea, salts, etc.)

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The Kidney Urine Formation
9
The Kidney Urine Formation

• Secretion
• Some other excess substances are actively
  transferred into the nephron for elimination

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The Kidney Urine Formation
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The Kidney Urine Formation

• Excretion
• Urine is carried by ureters to the bladder for
  storage (200 ml first warning, 400 ml second
  warning, 600 ml too late!)
• When it is time, urinary sphincter opens urine
  enters urethra exits body

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The Kidney Urine Formation
13
QUIZ Label!

• A Renal arteryD Bowman's CapsuleE
  GlomerulusG Loop of HenleI Collecting Tubule

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Kidney-Related Diseases

• diabetes, Brights disease, kidney stones, etc.
• SUMMARIZE using Pg. 213 text

The End!!!