Transcript Bio12 Respiration 2011

Respiratory System
Continued
Cellular Respiration Process
 Breathing: Inspiration and Exhalation
 External Respiration: exchange of gases between
blood and the atmosphere.
 02 in
CO2 and water out.
 Internal Respiration: Exchange of gases blood and
tissue.
 Once Mitochondria have oxygen cellular respiration
takes place.
 Conversion of 02 and sugar into CO2 and water
Path of Air
 Breathing is an unconscious process
 Air is drawn into the respiratory system through
negative pressure,
 Into the nostrils (mouth)
 Function to filter and trap particles in the air through the use
of hairs and MUCUS
 Large blood supply in the sinuses allows for WBC to be on
hand incase of pathogens.
 Next air moves past the PHARYNX and epiglottis which
covers the trachea during ingestion.
Path of Air
 When epiglottis is open, air passes through the LARYNX or
voice box into the TRACHEA.
 Vocal chords (tendons) vibrate and create high and low pitches
depending on how taut they are.
 Why doesn’t the trachea collapse when we’re not breathing?
 CARTILAGE: C-shaped rings line the trachea keeping it open.
 The trachea then begins to branch forming the left and right
BRONCHI which also contain cartilage rings.
 CILIA coat the trachea and bronchi: these microscopic protein
hairs beat constantly to move debris out of the respiratory system
where it can be swallowed or coughed out.
 As the BRONCHI begin
to narrow they become
known as
BRONCHIOLES. This
continued branching is
known as the Bronchiole
tree
 Finally the branching
ends at the ALVEOLI,
this is the site of
EXTERNAL
RESPIRATION.
Quick note:
 As air makes its way down the pathway
to the lungs it is warmed to 37 degrees
(Our normal body temp) as well as
saturate with water as it passes over
mucus lined paths in order to maximize
gas exchange.
ALVEOLI
 Each lung contains millions of these sac-like tissues.
 Their function is to provide a beneficial surface area for
the exchange of materials between the blood stream
and the outside world.
How much surface area?
 These little bags provide roughly 160 square meters of
surface area for the exchange of gases. That’s roughly
the size of a tennis court!
• =
Specialized Functions
 They are specialized in a number of ways.
 1. Alveoli walls are 1 cell thick.
 2. They have a coating of LIPOPROTEINS on the inner
surface which prevents them from collapsing and sticking
together during exhalation.
 3. STRETCH RECEPTORS: send signals to the medulla
oblongata indicating the are full enough. This triggers
exhalation.
 4. Surfaces are highly vascularized by PULMONARY
ARTERIES. Ensures maximum gas exchange
 5. Kept moist by circulatory system. Maintains flexibility
and aids gas exchange.
 KNOW THESE!!!!!!!!!
Mechanics of Breathing
 The ‘brains’ of the breathing system is the medulla
oblongata.
The Medulla Explained.
 The medulla contains the cardiac, respiratory, vomiting and
vasomotor centers and deals with autonomic, involuntary
functions, such as breathing, heart rate and blood pressure.
 From an evolutionist perspective it is referred to as the
primitive brain since it manages basic but life-essential
functions and does not allow for higher order thinking.
 Water Boy:
 http://www.youtube.com/watch?v=UfC4u5GCy3I

Our Medulla is kind of a big deal
 It is sensitive to CO2 and Hydrogen ions in blood
plasma.
 Both of these are toxins (Bi-products of cellular
metabolism) and need to be removed from our bodies.
 When H+ and CO2 concentrations get too high, the M.O.
triggers a contraction of muscles (Guess?) through nerve
impulses in order to promote breathing
Other sites of
Chemoreceptors
 The M.O. is not the only site in the body that monitors
the blood content in our bodies.
 The aortic arch and Carotid arteries also contain
CHEMORECEPTORS (Chemo=chemical).
 If these receptors detect poor O2 levels in the blood and
they may help trigger inhalation.
 This is a secondary mechanism though
 Most of the time our body works to detect CO2 and H+
levels in plasma.
Chain Reaction
 Two important muscles must contract inorder for us to
breath.
 They are…..
 The DIAPHRAM and INTERCOSTAL muscles.
 As stated previously, these contractions are cued by a
stimulus from the M.O.
 The Diaphram moves down during contraction and the
Intercostal musles move (effecting the rib cage) up and
out.
Creating the Vacuum
Mechanics continued.
• The combined effect of these muscles motions increases the
volume of the THORACIC CAVITY.
• As discussed previously this expansion creates a negative
pressure inside the thoracic cavity causing air to rush in.
Also Termed Vacuum effect.
• This bringing of air into the lungs is termed….
•
Inhalation of course.
• It is an active process requiring ATP
• Exhalation is a relaxing of these muscles.
Pleural Membranes
 The outer surface of the lungs is coated with a
PLEURAL MEMBRANE. (just remember pleural means
two, so it has two membranes)
 A second layer coats the inside of the thoracic cavity.
 Its function?
 To allow the surface of the lungs to slide easily over the
body wall and seal off the cavity.
Pneumothorax
 If a puncture should happen, breaking the air tight seal
of the lungs you may experience a
 PNEUMOTHORAX or in more common terms, a
collapse lung.
Gas Exchange: External
Respiration
 External Respiration: diffusion of Oxygen into the
pulmonary capillaries and diffusion of Carbon Dioxide
out through the alveoli
 Approximate conditions of Alveoli are:
 37 degree, pH of 7.38
 Under these conditions hemoglobin combines with
oxygen. Each Hb (Hemoglobin) molecule has 4 oxygen
binding site. As blood leaves the alveoli it is 99% saturate
with O2. That’s pretty good.
 This chemical combo is referred to as
OXYHEMOGLOBIN and is abbreviated as HbO2.
 From here its on to the heart and off to the tissue.
Gas Exchange: Internal
Respiration
 At the tissues the conditions are slightly different, but
this is important to Hb
 At the tissue, pH is 7.35 and our internal temperature is
slightly higher at 38 degrees.
 Hb can now release O2 in the capillary beds which
diffuses into the tissue along with water. (high to low
concentration!)
 On the other side of the capillary bed Hb can now
except some CO2 (carbaminohemoblobin HbCO2)
and metabolic wastes also enter the blood stream.
 Most CO2 however reacts with H20 thanks to
Carbonic Anhydrase (enzyme) forming Carbonic
Acid
 However this doesn’t last long.
 Quickly the molecule disassociates into BICARBONATE
ions and Hydrogen ions.
 Remember those? Remember their functions?
 Bicarbonate is our bodies pH buffer.
 H+ ions are acidic, not good. They bond with Hb as
well forming HHb, known as reduced hemoglobin.
Transport of Gases
Gas
Reacts with
Carbon
Dioxide
CO2
Hemoglobin
Carbaminohemoglobin
HbCO2
Carbon
Dioxide
CO2
Water
Carbonic Acid ->
Bicarbonate and H+
HCO3 + H
Oxygen
O2
Hemoglobin
Oxy-hemoglobin
HbO2
Hydrogen
Ions Acid
H+
Hemoglobin
Reduced Hemoglobin
HHb
Hemoglobin is responsible for transporting not only O2, but CO2 and
H+ the chemical formula also contains Hb which stands for
Hemoglobin.
Also note that the enzyme Carbonic Anhydrase plays a key role in
combining H20 and CO2 to form Carbonic Acid before they turn into
Bicarbonate and Hydrogen.
 Summary diagram is
available in your
study guides.
So what does our blood composition look
like at this point?
 Blood leaves the capillary bed, enters venuoles, then
veins of the systemic system. It returns to the right
atrium, right ventricle and makes its way back to the
pulmonary system.
 At this point as it arrives at the alveoli again its
composition is as follows:
 Bicarbonate ions, with some carbon dioxide gas.
 Hemoglobin is carrying either CO2 or H+
 Here remember the temperature is a little cooler and
pH is a little more basic (higher)
Review:
 With a partner:
 Create a basic diagram showing the heart and
pulmonary system. Include CO2, HbCO2 H20, O2,
Hb02, H+, HCO3, Hemoglobin. Where are these
molecules found?
 Include the temperature and pH during internal and
external respiration.
 Give 4 unique features of the Alveoli which allow them
to function properly.
 List in order all steps involved in taking a breath, begin
with the MO monitoring CO2 levels.
Healthy vs. Smokers Lungs
What’s in cigarettes

Cigarettes are made from tobacco, a tall leafy plant that is grown almost everywhere in the world. The tobacco plant
contains a drug called nicotine. Nicotine is a deadly poison - it can kill a person in less than an hour if even a small
amount is injected into the blood-stream. Tobacco smoke contains very tiny amounts of nicotine that aren't deadly, but
are still very bad for your health.

Tobacco smoke also contains over 4,000 chemicals, many of which are known causes of cancer. Just a few of these
chemicals ar

Carbon Monoxide (found in car exhaust)
, Arsenic (rat poison), Ammonia (found in window cleaner), Acetone
(found in nail polish remover), Hydrogen Cyanide (gas chamber poison), Napthalene (found in mothballs)

Sulphur Compounds (found in matches)

Lead

Volatile Alcohol

Formaldehyde (used as embalming fluid)

Butane (lighter fluid)
 When you smoke, all of these chemicals mix together and form a
sticky tar. The tar sticks to clothing, skin, and to the cilia (tiny hairs)
that line the insides of your lungs. The cilia help to clean out dirt
and germs from your lungs. If the cilia are covered in tar, they can't
do their job properly, and germs, chemicals and dirt can stay in
your lungs and cause diseases.
 Second-hand smoke is also dangerous
 Even if you yourself don't smoke, you can still get sick or die from
tobacco. When you breathe the smoke from another person's
cigarette, it can be as bad as smoking cigarettes yourself. Learn
more about what second-hand smoke does to your lungs
 Basics of
breathing:http://video.about.com/asthma/How-LungsFunction.htm
 Dr. Z gives a Bronchoscopy
 http://www.youtube.com/watch?v=v30vHFz1ZAY
 Bronchoscope introductions
 http://www.youtube.com/playlist?p=F8B79845A0DFD702