Gas exchange◦Bringing oxygen into the body

◦Getting rid of carbon dioxide

epithelial tissue that lines the trachea and bronchi produce mucus (traps dirt).

epithelial tissue also has cilia (microscopic hair-like structures) to move mucus and foreign material out.

trachea (windpipe) is supported by rings of cartilage (connective tissue) – keeps it open for air to flow freely

involves the diaphragm (a large sheet of muscle underneath the lungs) and the muscles between the ribs.

an involuntary process that we can override while talking but only temporarily

controlled by a part of the human brain that detects the concentration of CO2 in our blood

Air Pathwayair enters through the nostrils (air is filtered by nose hair) ↓nasal cavity (air is warmed and humidified) ↓ pharynx (throat) ↓ larynx (voicebox) ↓ trachea (windpipe)

↓ bronchi (there are 2, each leads to 1 lung) ↓

bronchioles ↓

alveoli (clusters of air sacs with a very large surface area, surrounded by capillaries)

Trachea (windpipe)◦tube that takes air from the back of the throat down to the lungs

Bronchi ◦as the trachea approaches the lungs it splits into two bronchi, one bronchus leads to each lung

◦continues splitting into small bronchiole tubes ending in the alveoli

Alveoli (singular: alveolus) millions of alveoli provide a large total surface area

for greater absorption of gases a thin, single layer of flattened cells are on the wall

of each alveolus to decrease the distance that gases need to diffuse across

a dense network of capillaries (tiny blood vessels) surrounding the alveolus remove CO2 from the blood and absorb O2

Hemoglobin, the protein found in red blood cells, pick up O2 from the alveoli to transport to the rest of the body

the circulatory system provides a good blood supply the lungs

the concentration of O2 in the blood that flows through the lungs is always less than the concentration of O2 in the air in the alveoli, therefore O2 always diffuses from alveoli into the blood.

Some contaminants in some people will trigger inflammation of the airways, i.e. asthma.

People with asthma inhale corticosteroids (using “puffers”) to reduce the inflammation.

infectious disease – easily spread caused by bacteria in the lungs general symptoms: fever, cough,

weight loss, fatigue, and chest pain. diagnosed by a chest X-ray. problem: TB bacteria can remain

dormant for many years – waiting for the immune system to be compromised to take over.

however, once detected, the disease can be successfully treated with medicine and/or a few weeks hospitalization

disease of the respiratory system symptoms: flu-like (high fever),

shortness of breath, dry cough, sore throat, headache, muscle pain, and exhaustion.

tobacco use – first and second-hand smoking is detrimental to the respiratory system

contains carcinogens (cancer-causing chemicals)

“What is Breathing and Respiration?” Package