Why humans have difficulty breathing in high elevations
Breathing in high elevation is affected by temperature, air pressure, oxygen levels, and dehydration. An individual will have difficulty breathing in high elevations because the air is colder, has fewer oxygen molecules as well as less dense. Higher attitudes lower the air pressure, which makes it difficult for oxygen to enter the vascular systems for diffusion, leading to less efficient uptake of oxygen. This is because oxygen levels decrease with an increase in altitude, making it hard for the lungs to take in the needed oxygen. Dehydration also causes difficulty in breathing as fast breathing results in high loss of fluid from the lungs.
Why does drowning cause death?
Drowning causes suffocation when the lungs are filled with water, which interrupts the process of oxygen absorption from the air. Inhalation of water into the air passages and the lungs causes asphyxia. Water inhalation causes will cause the victim to attempt to swallow or remove the water, causing an involuntary inhalation of water. The entry of water into the lungs reduces the absorption of oxygen in the lungs, which deprives the brain oxygen leading to cardiac arrest and eventually death. The presence of water in the lungs also damages the inner surface of the lungs by collapsing the alveoli resulting in reduced ability for air exchange.
Why gills work in water but lung do not
Gills work in water as a result of their efficiency in absorbing oxygen dissolved in water. Fish do not breathe oxygen from the air but absorb oxygen dissolved in water. On the other hand, lungs fail to operate underwater because they lack enough surface area to absorb oxygen dissolved in water. Lungs are adapted to enable breathing of air and not water in comparison to gills, which are designed to allow water to flow over them in one direction as blood flows in the opposite direction.