Gas Exchange Flashcards
What is the thorax?
Your Chest
What structures are involved in breathing?
trachea–> bronchi–> bronchioles –> alveoli.
ribs and intercostal muscles. Protection and moves your ribs. can change thorax volume for breathing in and out
diaphragm–> breath in = flattens= increase thorax size
breath out= relaxes to become a dome= decrease thorax size
How does the diaphragm change breathing?
When it relaxes and decreases thorax volume the pressure inside becomes higher than outside. This means that the air pressure outside it lower so you breath out.
(High to low pressure)
How to do the intercostal muscles aid breathing?
They move your ribs out and up when breathing in. This increases your thorax volume which decreases pressure inside compared to atmosphere pressure. Therefore air moves in.
How are alveoli adapted for gas exchange by diffusion?
High Surface area:volume ratio.
They are thin so reduced diffusion distance
There is a high concentration of oxygen in the alveoli compared to the blood so oxygen diffuses across.
What are the effects of smoking on the lungs and heart?
Cigarettes contain chemicals causing lung cancer such as tar
Emphysema- smoking breaks down alveoli which refuse forming irregular shapes with reduced surface area:volume ratio
Bronchitis- smoke causes mucus production which blocks airways and leads to coughing
Coronary Heart disease- smoking damages coronary arteries
How does coronary heart disease cause death?
smoking damages the arteries which the body repairs by depositing cholesterol.
cholesterol reduces the lumen size
therefore less blood can travel through the coronary arteries to the heart
Heart works harder to get more blood to it and more oxygen
Eventually lack of blood causes death of the heart cells and death
What is gas exchange?
The diffusion of oxygen and carbon dioxide into and out of cells and tissues
What is breathing?
The movement of air into and out of lungs due to changes in thoracic pressure.
