Initially, I thought of having a blow hole, like whales and
dolphins, so that I can swim in water. But then again, having a hole on top of my
head would be weird. So, if I am given the power to change the anatomical structure
of the human respiratory system, I would like to change one of the lungs to
gills. Because I will be able to walk on land and swim in water to travel
around and explore the underwater world.
The human respiratory system is a series of organs working
together in the exchange of gases. The primary organs of the respiratory system
are lungs which carry out this exchange of gases. The external respiration is
the exchange of gases between the alveoli and blood capillaries is dependent on
the disparity of the partial pressure, large surface area, minimum diffusion
distance and the rate of airflow into and out of lungs. Whereas the internal
respiration is the exchange of gases between the capillaries and tissue cells.
With that being said, the human’s lungs would not work very
well for a fish because breathing underwater would fill the lungs with water,
hence making it useless. Nevertheless, the fishes in the ocean need oxygen to
breathe too but they need specialized organs, gills, to help them do the work
by removing oxygen from the water.
The fish’s primary respiratory organ is gills which contain
full of blood vessels. Unlike humans, the fish uses its mouth to breathe by taking
in water forcefully through its gills. As water transported over the minute walls
of the gills, dissolved oxygen travel into the blood and to its cells. So, the
fish’s gills would not work very well for humans because the gills are not evolved
to extract oxygen from the mixture of air.
Many people have thought that whales are fish because they live
in water. In fact, whales are mammals, just like humans, who breathe through
lungs, give birth to young mammals and feed their young with milk. Similarly, the whales breathe through lungs, just
like humans, and that is one of the reason why they can swim to the surface of
the ocean. Don’t be mistaken, whales do not breathe in from nose like us. They
breathe in from a hole which is known as blow hole located at the top of their
In a nutshell, having both the lungs and gills allow me to
extract oxygen from air and water.