The lungs Flashcards
Starting at the mouth, in what order of structures does air pass through when we inhale/exhale?
Mouth/nose –> trachea –> bronchus –> bronchiole –> alveoli
<– trachea <– bronchus <– bronchiole <–
What is diffusion?
Movement of particles from a high concentration to a low concentration.
What is a concentration gradient?
A difference in concentration in two different areas.
In the alveoli: (2)
There is a high 02 concentration and a low CO2 con. The 02 diffuses into the blood (capillaries) whereas the CO2 diffuses out of the blood.
There is a high/low concentration of 02/CO2 in the blood.
High 02, low CO2.
Why are millions of alveoli found in the lungs?
Many alveoli provide a larger surface area for gas exchange to occur.
Why do alveoli have thin walls?
So that gases have a shorter distance to diffuse into the blood.
Why do alveoli have many blood capillaries?
More blood can reach the lungs, ensuring good circulation to maintain a conc. gradient.
Why do alveoli have a moist inner wall?
So gases can readily dissolve into moisture.
Why is important to maintain the concentration gradient between lungs/blood?
So gas exchange can occur by diffusion.
How can we maintain the conc. gradient? (2)
- Blood circulation
- Breathing/ ventilation
What is the equation for respiration?
Glucose + 02 (chemical reaction) –> CO2 + H20 (+energy)
What does asthma start with?
Coughing/ wheezing –> tightened chest –> hard to breathe
What causes an asthma attack?
When the inflamed airways of the lungs are triggered, they close up/contract.
What are some triggers of asthma attacks? (6)
Smoke, exercise, cold, weather, allergens and scented substances.
