The document discusses human respiration and ventilation. It describes how respiration involves cellular respiration, gas exchange through the lungs, and ventilation or breathing. It then discusses the importance of ventilation for providing a supply of oxygen and removing carbon dioxide to maintain gas exchange in the lungs. Finally, it provides details on the structure and function of the upper and lower respiratory tract and the process of breathing and gas exchange.

1. Human Respiration:
Ventilation
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2. Human Respiration
 Involves the process of:
a) cellular respiration:
Glucose + O2  H2O + CO2 + 36 ATP’s
b) gas exchange:
exchange of gases between the internal
and external environment with the use of
lungs
c. ventilation - breathing
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3. Ventilation System
why do we need it!?
 adequate lung ventilation is essential to
gas exchange
 ventilation provides a continual supply of
fresh air to the lungs needed to
maintain a large concentration gradient
for gas exchange >> surface of the
alveoli
 O2 must be delivered regularly
 CO2 must be quickly eliminated
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4. (I) Human Respiratory System
 Composed of a network of
passageways which permits
air to flow from the external
environment and into the
lungs
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5. The Upper Respiratory Tract
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6. Nasal Cavity
 The nose
 Lined with a ciliated
mucus membrane
 The cilia and mucus:
1. Filters air
2. Warms air
3. Moistens air
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7. Pharynx
 Known as the
throat region
 It is an area
in which both
air and food
pass through
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8. Larynx
 Humans
 use the larynx as a
voice box
 contains vocal cords
that vibrate and
produce sound as air
passes through
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9. Epiglottis
A cartilaginous
flap
 It “covers” the
trachea when
swallowing food
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10. Trachea
 Known as the windpipe
 Kept open by rings of
cartilage
 Lined with a ciliated
mucus membrane
 One cigarette
paralyzes the cilia for
20 minutes
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11. Lung
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12. Bronchi
 Bronchus = singular
 Trachea divides into two major
divisions known as bronchi
 The bronchi contain cartilage
rings as well
 The bronchi subdivide many times
forming smaller tubules known as
bronchioles
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13. Bronchioles
 Lack cartilage
rings
 Tiny bronchioles
subdivide and
terminate (end)
with structures
known as alveoli
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14. Alveoli
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15. Alveoli
 Are thin: single layer of cells – easy
diffusion
 Moist: helps gases to dissolve before
passing thru membranes/
 Alveoli increase surface area for gas
exchange
 Rich in blood vessels: O2 diffuses into
the blood from the alveoli and CO2
and water diffuse out of the blood
and into the alveoli
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16. (II) Breathing Process
 Inhaling – Inspiration
 Exhaling – Expiration
 Lungs are highly elastic (stretchable)
 Thoracic Cavity is sealed
 Atmospheric Pressure Constant
 Atmospheric Pressure forces air into the lungs:
 Volume Inc. / Pressure Dec. = Inhale
 Volume Dec. / Pressure Inc = Exhale
4 sets of MUSCLES that control breathing include:
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17. Diaphragm and Abdominal
Muscles
 Diaphragm contracts –
flattens dome – Inhale
 Abdominal muscles relax
 Diaphragm relaxes –
abdominal muscles
contract - Exhale
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18. Intercostal Muscles
 External Intercostals –
 Attached to rib cage
 Contracts to move rib cage up and out
 Inhale
 Internal Intercostal
 Attached to rib cage
 Contracts to move rib cage down and in
 Exhale
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20. II – Breathing Process
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21. III – Gas Exchange
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22. (III) Gas Exchange
• High Concentration gradient
needed.
• In the blood, hemoglobin binds
with oxygen from the alveoli to
form oxyhemoglobin (HbO2)
• Carbon dioxide is carried primarily
in the plasma of the blood in the
form of bicarbonate ions (HCO3)
Lung Attack – Gas Exchange
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23. THE END
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