-smoking disables the normal cleansing and protective mechanism of the
respiratory system. -smoking causes lung cancer- smokers account for
90% of all lung cancer cases.
-smokers have a higher rate of heart attacks and strokes.
-on average, adults who smoke die nine years earlier
than nonsmokers. -non smokers who are exposed to
secondary smoke are also at risk.
-shortly after quitting smoking, cilia function returns and normal mucus clearing
-breathing is the alternate inhalation and exhalation of air.
-when you inhale, your diaphragm contracts and moves downward, expanding the
-the volume of your lungs increases with the expanding chest cavity, which lowers
the air pressure in the alveoli to less than atmospheric pressure.
-flowing from a region on higher pressure to one of lower pressure, air is pulled
through the nostrils and down the breathing tubes to the alveoli- this type of
ventilation is called negative pressure breathing. -when you exhale, your rib
muscles and diaphragm both relax which decreases the volume of the rib cage
and chest cavity, increasing the air pressure inside the lungs, forcing the air out.
-tidal volume is the volume of air in each breath when you breathe quietly.
-vital capacity is the volume of air breathed during maximal inhalation and
exhalation- example: breathing heavy when you workout.
27.10 -although you can voluntarily hold your breath or breathe faster and deeper,
most of the time your breathing is under involuntary control.
-a breathing control centre in a part of the brai