Excretion:

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Excretion
Removal of harmful, toxic, metabolic waste
Metabolic Wastes
Physical respiration

• CO2

• H2O

Physical respiration, Dehydration Synthesis

• Nitrogenous Wastes

Protein Metabolism
- Ammonia
(most toxic)
- Urea
- Uric Acid
(least toxic)
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Organs Involved
Skin
Lungs
Liver
Kidneys
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What are the 4 major organs involved with
excretion
Liver
Skin
Kidneys
Lungs
Work together to maintain homeostasis
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Physical Respiration
Exchange of gases (CO2, H2O, O2)
Pathway of air
Nasal Passage
Pharynx
Larynx
Trachea
Bronchi/Bronchial tubes
Bronchioles
Alveoli
(respiratory surface)
LUNGS
150 million per lung
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Nasal Passage
Pharynx
Larynx
Trachea
Bronchi
Lung
Bronchial Tubes
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Nasal Passage
1) Hairs filter out large foreign particles
2) Mucus on walls trap bacteria and dust
3) Moistens air
4) Blood moving through capillaries warm inhaled
air
Pharynx
Connects oral cavity to nasal passage
Larynx
(Voice Box)
Between pharynx to trachea
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Trachea through Bronchial tubes
- transports air to alveoli
- walls produce mucus to trap bacteria and dust
- cilia line walls and beat mucus upwards
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Alveoli

• Are thin, moist and surrounded by capillaries
• Are the functional units for gas exchange between
  the lung and the blood
• Alveoli increase surface area for gas exchange
• O2 diffuses into the blood from the alveoli and
  CO2 and water diffuse out of the blood and into
  the alveoli

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Bronchial Tube
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Alveoli
Bronchiole
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(II) Breathing Process
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What part of the brain controls breathing?
(involuntary behavior)
Medulla
To what is the medulla responding?
Carbon Dioxide concentration in the blood
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Effects of Smoking

• paralyzes cilia in the
• respiratory tract

• increases production of
• mucus (smokers cough)

• smoke particles eventually break down alveoli
  wall
• forming scar tissue. Lungs lose elasticity
  becoming
• less functional

• Smoke contains carcinogens (cause lung cancer)

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Healthy Lung Tissue
Diseased Lung Tissue
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Disorders of the Respiratory System
Asthma
- Severe allergic response

• Contraction of bronchioles
• making breathing difficult

- Fatigue
Bronchitis
- inflammation of the lining of the bronchial
tubes
- results in a severe cough and difficulty
breathing
- fatigue
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Emphysema
- lungs lose elasticity
- results in shortness of breath, difficulty
breathing
- fatigue
Pneumonia
- alveoli become filled with fluid
- prevents exchange of gases at alveoli
- severe cough, chest pain
- fatigue
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Lung Cancer

• tumors form in lungs (irregular uncontrolled
  cell
• growth)

- lungs lose elasticity, breathing difficulty
- fatigue (eventually death)
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Liver
Regulates body fluid composition

• Detoxification of blood

• Synthesis of bile

• Urea formation (amino acid break down)

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Skin
Epidermis
Dermis
Sweat Gland
Hair Follicle
Nerve
Sebaceous Gland
Fatty Tissue
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Sweat Glands
- Release perspiration
- Sweat contains water, urea and salt
Functions

• Excretion

• Regulation of body temperature

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Video 2
Video 2
Kidney Function

• Click the image to play the video segment.

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Kidneys
Functions

• Remove metabolic waste from the blood
• Salt, urea, (water)
• Regulates composition of body fluids
• Control concentration by eliminating/holding
• onto water

Nephron
(functional unit)
- 1.25 million per kidney
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(No Transcript)
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Path of Urine Excretion
Kidney
Ureters
Urinary Bladder
Urethra (boys and girls both have!)
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How do the kidneys maintain homeostasis? (How do
the kidneys regulate blood/urine
composition?) During exercise After
drinking After eating salty chips
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Causes of Kidney Disease
- infections
- heart disease
- toxic substances

• environmental pollutants
• (heavy metals lead and mercury)

- diets high in protein
- crash diets
Gout

• Excess uric acid crystals precipitate out of
  blood
• into joints

- cause is high protein diet (red meat)
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Kidney Threshold level
if the concentration of a substance in the blood
exceeds a certain level, the excess is NOT
reabsorbed Problems Diabetes the blood
sugar level is so high that glucose in the
filtrate will not diffuse back into the blood
stream. so glucose is present in the
urine. Kidney stones hard mineral and
crystalline material formed within the kidney or
urinary tract.
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Dialysis

• When a set of kidneys don't do their job, their
  owner has what is called a chronic kidney
  condition. Eventually, those kidneys may be
  considered failing. Much like a filter system
  hooked up to a pool, dialysis gives the kidneys a
  break by skimming waste for them.
• How does it work? A filtering machine is used to
  remove waste and extra fluid from your blood.