Download Respiratory System Lecture

• The beginning.
• Oxygen first enters your
body and Carbon Dioxide
leaves
• Air enters the nose and is
filtered by tiny hairs called
cilia, it is moistened by the
mucus that lines the nasal
passage.
• The cilia and the mucus
filter dust and pathogens
from the air.
• Air can also get into your
body through your mouth
or the oral cavity but air
is not filtered as much
when it enters in through
your mouth
• Pharynx or throat
• This is where the air
passes from your nose to
your bronchi tubes and
lungs
• Your pharynx (throat)
gathers air after it
passes through your nose
and then the air is
passed down to your
trachea (windpipe).
• Long structure made up of
soft tissue that connects the
mouth and nose to the
lungs
• The trachea is held open
by partial (or incomplete)
rings of cartilage
• Without these rings your
trachea might close off
and air would not be able
to get to and from your
lungs.
• Your trachea splits up into
two bronchi tubes.
• Each branch going to a
lung
• The bronchi tubes are like
tree branches that get
smaller and smaller, till
they become the
bronchiole
• At the end of the
bronchiole are tiny air sacs
called Alveoli
• There are 300 – 600
million alveoli in the lungs.
• They are tiny air sacs that
are highly folded and fill
up with air/oxygen when
you breathe in
• Your alveoli are
surrounded by many tiny
blood vessels called
capillaries
• Respiratory system is the system that helps you breathe in and
out
• Oxygen (O2) can be pumped through your body
• Carbon dioxide (CO2) can be removed from the blood stream.
• An internal structure to avoid water loss by evaporation
• Flow of air: Nose /mouth – Larynx – Trachea – Bronchi –
Bronchiole – Alveoli – Closed Blood Vessels
• System of tubes is restricted to one body area (the Thoracic
Cavity)
• Gas exchange surface is the wall of the alveolar sac because it
is wet, thin and highly folded.
• Requirements of a
successful respiratory
surface:
• Large surface area
• Very thin (one-cell thick)
• Moist or wet surface
• The walls of your alveoli (and capillaries) are so thin that the
oxygen or carbon dioxide can pass through them, traveling
right into, or out of your blood stream
• Diffusion of O2 and CO2 is driven by pressure gradient (gases
move from areas of higher partial pressure to lower partial
pressure.)
• Direction of O2: lungs to cells
• Direction of CO2: cells to lungs
• Primary Transport forms
• Oxygen: as O2 bound to hemoglobin
• Carbon Dioxide: As HCO3- (bicarbonate in plasma)
• CO2 is produced at the tissue level
• Red Blood Cells convert CO2 to HCO3• HCO3- dissolved travels to lungs
• Tissue-Level reactions are reversed within the lung
• CO2 is produced, then exhaled
INHALATION
Diaphragm contracts
(moves down)
EXHALATION
Diaphragm relaxes
(moves up)
Rest
• Ventilation rate
• 12 breaths per minute
• Tidal Volume
• 0.5 L
• Total Ventilation
• 6.0 L per minute of air
Exercise
• Ventilation rate
• 48 breaths per minute
• Tidal Volume
• 4.0 L
• Total Ventilation
• 192 L per minute of air