The creator of the laryngoscope lived in the 19th century, he had an indisputably Spanish name: Manuel; and a last name with a marked Hispanic accent: García. He was not a biologist or a doctor, he was simply a singing teacher.
It was his infinite curiosity and his excessive desire to discover the mechanism of the voice that led him to design the first gadget to observe the vocal cords and, with it, gave birth to a new discipline: laryngology.
lower than expected
The function of the larynx is threefold: protection, breathing, and sound generation. If we compare the human larynx with that of primates, there are big differences, on the one hand, theirs consists of a “membrane” that helps them emit different sounds and acoustic distortions. Thanks to her, they call out that enormous variety of squeals and grunts, of different intensities and tones, that we all know.
The loss of this laryngeal structure allowed us the ability to produce other types of sounds, much more harmonic, which ended up giving rise to human language. The anatomical simplicity of our larynx would be based on the concept of “use it or lose it” -use it or lose it-, in such a way that a creature maintains a physical characteristic if it uses it to survive, otherwise it slowly eliminates it.
On the other hand, our larynx is located at a much lower level in the neck, an anatomical idiosyncrasy that allows us to be able to speak, although for this we have had to pay a high price: choking, in the event that we try to swallow and breathe simultaneously. A disadvantage that, obviously, has been overlooked by evolution.
The epiglottis protects us
Anatomically, both the mouth and the pharynx are part of the digestive tract and the respiratory tract. From the pharynx, food continues its way through the esophagus to the stomach, while the air continues through the respiratory tract and reaches the larynx.
It is known as aspiration or broncoaspiration when food or liquids accidentally enter the airways. This is a situation that can have serious health consequences, as it can lead to pneumonia.
To prevent this from happening, nature has endowed us with the epiglottis, a small flap of rigid tissue that folds backwards when we swallow and closes the entrance to the larynx and trachea, thus preventing food from entering the respiratory tract. After swallowing, the epiglottis returns to its original position.
For its part, in the process of breathing the epiglottis remains elevated and the soft palate descends, facilitating the passage of air from the pharynx to the larynx and, finally, to the trachea.
Babies can too
Because the larynx occupies a higher position in the neck in primates, as we have seen, almost at the exit of the oral cavity, they can swallow food and breathe simultaneously without running the risk of choking.
Now, we have all observed that babies have no problem breathing and sucking at the same time. The explanation is anatomical, because during the first six or seven months of life the larynx is in a high enough position so that there is a reasonable distance between the trachea and the esophagus, so that there is a risk of choking. In addition, the hard palate has transverse folds that allow it to hold the nipple and facilitate the swallowing process.
Many centuries ago Plato defined man as a featherless biped, an animal that walks on two legs and lacks feathers. To that definition, and in light of current knowledge, it is possible that he added “choking primate.”