Human Organ Systems

1
Human Organ Systems

• The Excretory System

2
What is the function of the Excretory system?

• The job of the excretory system is to remove
  metabolic wastes from your body.
• Metabolic wastes are those that are created by
  the life processes within your cells.
• Remember that the wastes removed from your body
  by your digestive system (Feces) are not
  considered metabolic wastes.

3
The rule of 4

• For this organ system, 4 is a magic number to
  remember.
• For instance, there are 4 metabolic wastes
  created by your body.
• Water
• Carbon dioxide
• Salts
• Urea

4
More on 4

• Not only are there four metabolic wastes, there
  are 4 organs that remove these wastes.
• Skin Lungs Liver Kidneys
• (There are actually 4 components which make up
  our urinary system.)
• 1. Kidneys
• 2. Ureters
• 3. Urinary bladder
• 4. Urethra

5
The Skin

• The largest organ in your body, the skin gets rid
  of metabolic wastes in the form of sweat.
• Sweat consists of water, salts and urea.
• The sweat is formed in specialized sweat glands
  in your skin.

6
The Liver

• While your liver does not excrete anything from
  your body, it is responsible for filtering your
  blood and forming a nitrogenous waste called
  urea.
• Once formed, the urea is then secreted back into
  your blood.
• Its molecular formula is (NH2)2CO2
• Thought question Since Urea is a nitrogenous
  compound, from which component of human nutrition
  is this waste derived from?

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The Lungs

• Your lungs help to get rid of two metabolic
  wastes
• CO2
• H2O
• These wastes diffuse from the capillaries in your
  alveoli.
  
  
  

Normal lung
Lung Cancer
Emphysema Lung
8
The urinary system

• This system consists of 4 components.
• 1. Your Kidneys You kidneys filter your blood
  and remove Urea, excess water and salts. These
  are combined to form Urine.
• 2. The ureters are tubes that transfer urine
  from the kidneys to the urinary bladder.
• 3. The urinary bladder is a temporary holding
  sac for urine.
• 4. The urine leaves your body through your
  uretha. In males, the urethra is also part of
  the reproductive system.

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Quik quiz

• Please turn over your note worksheet and try to
  answer the following questions.
• 1. Name the four metabolic wastes.
• 2. Name the four organs involved in excretion.
• 3. Where are metabolic wastes created?
• 4. Which chemical reaction(s) in your body
  produces water?
• 5. Which chemical reaction produces salt?

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Excretion Summary
Organ Function/Wastes excreted
Skin Excretes water, salts and urea in the form of sweat.
Liver Filters blood of nitrogenous wastes and creates Urea.
Lungs Excretes water and carbon dioxide during exhalation.
Kidneys Filters blood of Urea, Salts and water and creates Urine. Excretes urine with help from the ureters, urinary bladder and urethra.