Douglas Todey
Functions
 The main function is to deliver oxygen to the blood
 The four main functions can be described with the
acronym VEEM
 Ventilate the lungs
 Extract oxygen from the air and transfer it to the
bloodstream
 Excrete carbon dioxide and water vapor from the lungs
 Maintain the acid base consistency of the blood
Characteristics of Alveoli
 The primary gas exchange units of the lung
 The exchange of carbon dioxide and oxygen happen in the
alveoli
 Oxygen diffuses through the walls of the alveoli into the
red blood cells. The oxygen is then carried by the blood to
the body tissues.
 Carbon dioxide produced by the body returns to the lung
via the blood. It then diffuses
across the capillary and alveolar
walls into the air to be removed
from the body
Characteristics of Alveoli
 Alveoli have a specialized structure that optimizes gas
transfer
 Extremely thin walls
 A large surface area to volume ratio
allowing for gases to flow across the
membrane easily
 They’re lined with fluid enabling gases to dissolve.
 Surrounded by numerous capillaries that carry oxygen
into the blood and bring carbon dioxide back to be
respirated out
Oxygen Transportation
 Oxygen combines with hemoglobin in red blood cells
forming a compound called oxy-hemoglobin
 When the oxy-hemoglobin hits the tissue, it breaks up
releasing most of its oxygen
 Approximately 3% of oxygen dissolves in the blood
plasma and enters the tissue by
diffusion
CO2 Transportation
 Carbon dioxide is transported back to the alveoli by
diffusing through the tissue fluids and then moving with
the blood back to the lungs
 Carbon dioxide is transported in three compounds:
 Carbonic Acid – approximately 10% of dissolved CO2 in the
blood
 Bicarbonates of Sodium and
Potassium – approximately 80% of
the dissolved CO2 in plasma
 Carbominohemoglobin –
approximately 10% of dissolved
CO2 in the blood
Oxygen: From Breath to Blood
1. Oxygen enters the body through the mouth and nose
2. The oxygen then passes through the trachea and the
3.
4.
5.
6.
larynx
Once in the chest cavity, the trachea splits into two
bronchi
Which then divides again into the bronchial tubes
The bronchial tubes lead into the lungs where they
divide into smaller and smaller tubes where they
connect to the alveoli
The alveoli then transfer the oxygen through their
outer membrane and into the hemoglobin found in
red blood cells
Ventilation System
Inhalation and Exhalation
 Inhalation is a result of two body processes
1. The intercostal (rib) muscles expand outward
2. The diaphragm expands downward away
from the lungs
 The result of both of these happening simultaneously
creates a low pressure area in the chest cavity so air from
the higher pressure outside the body rushes into the body.
 Exhalation is just the reverse process of inhalation
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
The intercostal muscles contract and the diaphragm expands
upward into the lungs
This creates a higher pressure than outside the body, so the air
in the lungs is forced out and you exhale
Asthma
 Approximately 10 million people, 10% of Americans,
have asthma, which kills 4,000 people per year
 Asthma is hypersensitivity of the respiratory system
airways, and when triggered constricts the airways.
This then constricts the airflow and causes trouble
breathing.
 Signs of asthma include wheezing and shortness of
breath
 The two main treatments for asthma are
bronchodialators that expand the bronchial tubes, and
anti-inflammatory medication to reduce the
inflammation of the airways
Lung Cancer
 The National Cancer Institute estimates 226,160 new
cases of lung cancer in 2012, which will kill 160,340
people
 Lung cancer is cancer that forms in the tissue of the
lung. The two types are Small Cell and Non-Small Cell.
 Symptoms include cough, shortness of breath,
wheezing, chest pain, and coughing up blood
 Treatment options include surgery, chemotherapy,
radiation therapy or any combination of the three
References
 http://www.ambulancetechnicianstudy.co.uk/respsyst
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em.html
http://www.curoservice.com/parents_visitors/lungs_ci
rculation/structure_alveoli.asp#
http://www.preservearticles.com/201102264268/transp
ort-of-oxygen-and-carbon-dioxide-through-bloodduring-respiration.html
http://www.nsbri.org/humanphysspace/focus2/respira
tory.html
http://respiratory-supplies.medical-suppliesequipment-company.com/PPF/page_ID/62/article.asp
http://www.cancer.gov/cancertopics/types/lung