gaseous exchange in humans
structure of human thorax
Trachea- Windpipe draws air from outside to the lungs
Bronchi - the two tube like things which trachea splits into two
bronchioles - branches of bronchi
alveoli - air sacks at the bottom of the thorax
diaphragm - the muscle at the lower bottom of thorax controls the contraction and relaxation of lungs
lungs - the bones which protects the lungs and its inside organ
inter coastal muscles - the muscles located between the ribs
Gas Exchange - transfer of oxygen into the blood and CO2 out of the blood across the alveoli walls
Inhalation- ribs move up and out and diaphragm contracts and flattens so volume increases and pressure decreases so air moves into lungs to expand. (external intercoastal muscles contracts and internal intercoastal muscles relax)
Exhalation- ribs move down and in and diaphragm relaxes and curves to decrease volume and increases pressure so air moves out of the lungs to deflate. (external inter coastal muscles relax and internal internal coastal muscles contract)
consequences of smoking
carbon monoxide
reduces OXYGEN carried as it blinds irreversibly to hemoglobin making carboxy hemoglobin
Nicotine
Heart disease-narrows blood vessels , increasing blood pressure and resting heart rate
It is highly addictive
Coronary heart disease- coronary arteries narrow that supply heart with blood , meaning less blood will be supplied to them: less oxygen,reduces rate of aerobic respiration which increases risk of heart attack and strokes as coronary arteries are blocked by cholesterol (blood cloths)
Adaptation of alveoli
permeable- gases can go through or pass
Moist surface-gases can dissolve for faster diffusion (stops inner walls from sticking together)
Large surface area-highly folded and a lot of alveoli to allow for faster diffusion
Thin walls-diffuse distance is shorter
Good blood supply-to maintain a higher concentration to diffuse faster