Transcript Gas Exchange - Crestwood Local Schools

Gas Exchange
Lizzie Cymanski
Functions
Acquisition of oxygen
Distribution of gases
Removal of carbon dioxide
Importance
Oxygen is needed for
cellular respiration
The body needs to
get rid of carbon
dioxide, the product of
cellular respiration
Cellular Respiration vs.
Respiration
Cellular Respiration -- the use of oxygen and
production of carbon dioxide at a cellular level
-
also called internal respiration
Respiration -- the uptake of oxygen from the
environment and the disposal of carbon dioxide
at the body system level
-
also called external respiration
Respiratory system needs:
large respiratory surface (lungs, gills)
a method for ventilating respiratory surface
a pump and circulatory system to distribute
gases
Bacteria
In bacteria and other very small organisms, cells
are in always in contact with the environment
Gas exchange happens easily
Respiratory Surfaces
The first respiratory surface was skin
doesn’t work for larger animals
Most amphibians still use skin for 100% of their
gas exchange
Fish, reptiles, humans get some respiratory
gases from skin
Evolution
As animals grew larger, their body’s surface area
wasn’t large enough for gas exchange through
skin
Aquatic animals developed gills, terrestrial
animals developed lungs
Lungs
Humans have two lungs -- the left divided into
two lobes, the right, three
Two zones -- the conducting zone and the
respiratory zone
Protected by the rib cage
Conducting Zone
Trachea -- connects the pharynx to the lungs,
allows the passage of air
Trachea divides into two bronchi which divides
into bronchioles which divides into terminal
bronchioles
No gas exchange with blood
Warms, cleans and humidifies air
Reinforced with cartilage to keep airways open
Respiratory Zone
alveolar ducts -- the tiny ends
of the airways
alveoli -- form at the end of
alveolar ducts, sac-like
structures, site of gas
exchange
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Pleural Cavity
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Lungs covered in visceral pleural membrane
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Lungs lined in parietal pleural membrane
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The pleural cavity is the space between the two
membranes
•
The cavity is filled with water to hold the two
membranes together
Interesting Facts
The lungs:
contain 1500 miles of airways
300 to 500 million alveoli
total surface area of 70 sq. miles -- about the
size of one side of a tennis court
If all the capillaries were unwound, they would
be 620 miles long
Circulatory System
•
The circulatory delivers the oxygen to cells all
over the body and then carries away carbon
dioxide
•
Most oxygen is bound to molecules of
hemoglobin inside red blood cells
Hemoglobin
•
A protein made of four polypeptide bonds and four
organic compounds called heme groups
•
At the center of each heme group is an atom of iron
•
The iron molecule can bond to a molecule of oxygen
•
Each hemoglobin can carry four oxygens
(De)Oxyhemoglobin
•
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Oxyhemoglobin – hemoglobin that is full of
oxygen, a bright red color
Deoxyhemoglobin – hemoglobin that has
released its oxygen, a dark red that appears blue
under tissue
History of Hemoglobin
•
Hemoglobin is an ancient protein
•
Not only used in vertebrates but also in annelids,
mollusks, echinoderms, flatworms, and even
some protists
•
Other invertebrates use hemocyanin which has a
base of copper instead of iron
Emphysema
One of the main forms of Chronic Obstructive
Pulmonary Disease (COPD)
The destruction of the lungs over a long period of
time
Most common cause is smoking, also caused by
exposure to pollution
Cannot be cured but can be treated
Emphysema Symptoms
Cough with mucus
Shortness of breath
Fatigue
Wheezing
Frequent respiratory infections
Tuberculosis
Caused by the bacteria Mycobacterium
tuberculosis
Very contagious
Can be cured but takes very long time
If not treated properly, spreads to other organs
TB Symptoms
Cough
Coughing up blood
Excessive Sweating
Fatigue
Fever
Weight loss
Cystic Fibrosis
Inherited disease
Causes thick, sticky mucus to build up in lungs
and digestive tract
May also affect sweat glands and male
reproductive system
Most commonly affects Caucasians
Only live to mid-30’s
Cystic Fibrosis Symptoms
Salty-tasting skin
Frequent lung infections
Wheezing and shortness of breath
Delayed growth
Problems with bowel movement
http://cwx.prenhall.com/bookbind/pubbooks/martini10/c
hapter24/custom2/deluxe-content.html
http://www.ncbi.nlm.nih.gov/pubmedhealth/
http://www.google.com/images
http://health.howstuffworks.com/humanbody/systems/respiratory/lung.htm
http://icb.oxfordjournals.org/content/28/2/739.abstract