Transcript Respiratory system - simonbaruchcurriculum

Why do we have a respiratory system?
1.
Movement of an oxygen-containing medium (air)
so it contacts a moist membrane overlying blood
vessels. (ie the role of Breathing)
2.
Diffusion of oxygen from the medium into the
blood. (ie the role of alveoli)
Transport of oxygen to the tissues and cells of
the body. (ie the role of the red blood cells in the
arteries)
3.
4.
Diffusion of oxygen from the blood into cells. (ie
the role red blood cells in the capillary beds)
5.
Carbon dioxide follows a reverse path. (ie the
role of the red blood cells/Plasma in the veins)
The Human Respiratory System
Structures in the Human Respiratory System
Lungs
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Lungs are ingrowths of
the body wall and
connect to the outside
by as series of tubes
and small openings.
Lung breathing
probably evolved about
400 million years ago.
Gas exchange in the Lungs
The diaphragm is the muscle that controls the breathing process. As the
diaphragm flattens it causes the chest to expand and air is sucked into the
lungs. When the diaphragm relaxes, the chest collapses and the air in the
lungs is forced out.
Control of Respiration
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Muscular contraction and relaxation
controls the rate of expansion and
constriction of the lungs. These muscles
are stimulated by nerves that carry
messages from the part of the brain that
controls breathing, the medulla. Two
systems control breathing: an automatic
response and a voluntary response.
The process of breathing
The figures in Breathing
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Gas exchange occurs in the alveolus where the
thin laminar blood flow and inspired air are
separated only by a thin tissue layer.
Gas exchange takes 0.25 seconds or 1/3 of the
total transit time of a red cell.
The entire blood volume of the body passes
through the lungs each minute in the resting
state, that is 5 liters per minute.
The total surface area of the lung is about 80
meters square, equivalent to the size of a tennis
court.
Air sacs- Alveoli
Exchange of gases in the alveoli
Movement of CO2 out of cells, in the blood and
finally out body via the lungs
In the alveoli capillaries, bicarbonate combines with a hydrogen ion
(proton) to form carbonic acid, which breaks down into carbon dioxide
and water. The carbon dioxide then diffuses into the alveoli and out of
the body with the next exhalation.
Can you name the parts of the human
respiratory system?
Lung disorders
Respiratory quiz