Transcript Regents Biology

Unit 2 Topic 5
The Respiratory System
What is respiration?
 Exchange of gases between the internal
environment and the external
environment
Need O2 in (for cellular respiration)
 Need CO2 out (waste product)

C6H12O6
Cell
ATP
O2
CO2
Respiratory systems

General characteristics
of respiratory systems:
1.
Thin, moist surfaces
2.
Large surface area:
volume ratio
 Mechanisms of gas
exchange in animals:
1.
2.
3.
4.
Direct with the
environment
Tracheae
Gills
Lungs
Lungs: Our system of gas exchange
A
B
C
D
E
F
G
I
H
E
Negative pressure breathing
inhale
exhale
Sort of random video…
78% nitrogen
21% oxygen
QuickTime™ and
a
0.04%H.264
carbon
dioxide
decompressor
are needed to see this picture.
How do you think this information relates to gas exchange?
Alveoli
Moving gases into bloodstream
 Step 1: Inhale to fill lungs with “fresh” air

O2 passes from alveoli to blood by simple
diffusion (high to low concentration)

CO2 passes from blood to alveoli by simple
diffusion (high to low concentration)
Capillaries carrying
low O2 / high CO2
concentration blood
back from body.
 Step 2: Exhale to
empty lungs.
Capillaries carrying
high O2 / low CO2
concentration blood out to
the body.
Red blood cells and hemoglobin
Blood=
45% cells (red, white, platelets)
55% “plasma” (nutrients, water,
vitamins, hormones, cellular
waste, ions)
Respiratory System
Special Topics
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Chronic Respiratory Diseases
Common respiratory infections
 Pneumonia
 Bronchitis
Smoking and the lungs
Cigarette smoke: carbon coated in 4,000 toxic
chemicals





Benzene
Ammonia
Formaldehyde
Arsenic
Cyanide
Smoking:
 Causes cilia to stop moving (for 20 minutes)
 Increases amount of mucus in the air passages




(cilia no longer clearing mucus)
Kills immune cells on respiratory tract
Decreases the amount of oxygen carried by
blood
Leads to tar build-up in your lungs
Second-hand smoke also contains many toxins
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Lung Cancer
 Tumors form in the lungs
www.lungcancer.au.com
Cystic Fibrosis





Genetic disorder that affects the structure of 1 protein.
Chloride ions protein pumps in cells of the trachea don’t work
Results in production of abnormally thick and sticky mucus
Mucus builds up in lungs and pancreas
People with this disorder live much shorter lives (now up to late
30s/early 40s, only a couple of decades ago, most died in
childhood)
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