The 4 differences between pharynx and larynx (explained)

The human body is much more than the sum of the thirty trillion cells that make up our being. We are a feat of biological evolution, an almost perfect machine in more than 80 different organs working in a coordinated way so that we can fulfill our physiological functions and have an anatomy and morphology capable of developing mechanical functions.

And although it is normal that, either due to their size and / or physiological relevance, they are the best known (such as the heart, brain, lungs, skin, liver, kidneys, eyes, etc.), there are others that , despite being just as important in our body, they are a bit in the shadow of the most famous and can even be confused between them.

And in this context, there are no two organs that we tend to confuse more with each other than the pharynx and larynx. Both are tubular organs of the respiratory system that, in addition, are followed by each other. All this, added to the fact that at a grammatical level there is only one letter of difference between them, makes us often make mistakes when it comes to differentiating them and being clear about their nature.

It is precisely for this reason that in today's article and, as always, from the hand of the most prestigious scientific publications, we are going not only to detail the morphological and physiological properties of both the pharynx and larynx, but to investigate, in the form of key points, the differences between the two organs of a tubular nature. Let us begin.

What is the pharynx? And the larynx?

Before going in depth and analyzing the main differences between the two bodies, it is interesting (and important) that we put ourselves in context and understand the nature of each of them. In this way, both your relationship and your differences will begin to become much clearer. So let's see what exactly is the pharynx and what is the larynx.

Pharynx - what is it?

The pharynx is an organ of a tubular and muscular nature that is part of both the human respiratory and digestive systems.. It is a tube located in the neck that communicates the mouth with the esophagus and the nostrils with the larynx, the next respiratory structure that we will analyze below. Therefore, it fulfills a non-exclusive respiratory function, as it is also part of the digestive system.

We are, as we say, before a tubular organ of a muscular nature and about 15 centimeters in length and a diameter of between 2 and 5 centimeters that conducts the inhaled air to the larynx when we are breathing but also, when we eat, it carries food and liquids that we ingest to the esophagus, which is a tubular organ that, being an extension of the pharynx, is already part only of the digestive system, being the conduit (between 22 and 25 centimeters in length) that leads the food bolus from the end from the pharynx to the stomach, where digestion that had partially started in the mouth will follow.

But going back to the pharynx, this organ must have a muscular nature (it is supported by the constrictor muscles of the pharynx) in order to adapt to the bolus and allow it to descend properly without causing obstructions. The pharynx is tube-shaped, lined by a mucous membrane, and, as we see, it fulfills many functions such as swallowing, breathing, phonation, and even hearing.

The pharynx is divided into three parts. The first, the nasopharynx, is that most superior portion that emerges from the posterior region of the nasal cavity and descends to the area of ​​the mouth. The second, the oropharynx, is the middle portion that extends from the soft palate to the epiglottis, a sheet-shaped organ that, at the moment of swallowing, closes the upper opening of the larynx. This is essential so that food does not pass into the tubes of the respiratory system and is redirected to the esophagus to reach the stomach.

And the third, the laryngopharynx, is that lower portion through which the air advances in case the epiglottis is not closing the opening to the larynx, being the transition zone between the pharynx and this larynx, the next organ that we are going to analyze. This entrance to the larynx is delimited by what are known as arytenoepiglottic folds. Thus, the epiglottis, which is located in front of the larynx, when in its upright position, keeps the opening to the larynx open. With this understood, let's go on to analyze this larynx.

Larynx - what is it?

The larynx is an organ of a tubular and cartilaginous nature that is part of the human respiratory system. It is a tube that receives air from the pharynx and leads it to the trachea, the tube that, descending from the fourth thoracic vertebra, carries air to the lungs. Well, the larynx limits its function to making air reach this trachea.

And for this, you do not need too long a length. In fact, it measures just 44 millimeters in length, having, yes, a diameter of 4 centimeters. And as we have already hinted, the larynx is not muscular in nature, but cartilaginous. That is, it is not made up of muscles, but is a structure made up of 9 cartilages whose only function (in addition to housing the vocal cords, thus being the organ of phonation par excellence) is to serve as a connection between the pharynx and the trachea, ensuring proper air flow and preventing swallowed food from passing to deeper regions of the respiratory system.

Thus, the larynx is composed of cartilaginous tissue, a type of connective tissue rich in chondrogenic cells, elastic fibers, and collagen. A) Yes, the larynx is made up of 9 pieces of cartilage, three odd (the thyroid cartilage, the epiglottis and the cricoid cartilage) and three even (the arytenoid cartilages, the cuneiform cartilages and the corniculate cartilages). Together, being articulated and lined by mucosa and moved by muscles, these cartilages constitute the larynx.

How are the pharynx and larynx different?

After analyzing the physiological properties and morphological characteristics, surely their differences (but also evident relationship) have become more than clear. Even so, in case you need or simply want to have the information with a more visual character, we have prepared the following selection of the main differences between the pharynx and larynx in the form of key points.

1. The pharynx is part of the respiratory and digestive system; larynx, respiratory only

The most important difference. The pharynx is an organ that is part of both the respiratory system (with the function of conducting the inhaled air to the larynx) and the digestive system (when we eat something, it leads the bolus to the esophagus, which will carry the food to the stomach). Therefore, it has a respiratory and digestive function.

The larynx, on the other hand, is no longer part of the digestive system, only the respiratory system. And its only function (in addition to housing the vocal cords, thus being essential for phonation) is to serve as a connection between the pharynx and the trachea, the conduit that will carry air to the lungs. Therefore, it has an exclusively respiratory function. Under normal conditions, food never passes into the larynx.

2. First comes the pharynx; then the larynx

It may be obvious having analyzed the previous point, but it should be mentioned since it is the most common confusion that we usually make. On the way through the respiratory system, air first passes through the pharynx and then through the larynx. In fact, the complete order of the inhaled air is as follows: nostrils (or mouth, although it is not recommended to breathe in through it), pharynx, larynx, trachea, bronchi (which are already inside the lungs as such), bronchioles and alveoli pulmonary, where gas exchange takes place.

3. The pharynx is longer than the larynx

Regarding the length, there are also important differences. The pharynx is, in comparison, much longer than the larynx. And is that while the pharynx is about 15 centimeters long, the larynx is just 44 millimeters.

4. The pharynx is muscular in nature; larynx, cartilaginous

And we end up with a key difference when it comes to morphology and physiology. And it is that while the pharynx is a tubular organ of muscular nature, the larynx is also an organ tubular but not muscular in nature, but cartilaginous in nature. The pharynx is supported by the constrictor muscles of this and other accessory muscles, thus being a muscular tube lined by a mucous membrane.

The pharynx must have this muscular nature since it is not limited only to conducting air, but in its role as an organ of the digestive system, it must carry the food bolus to the esophagus. And for this, movements are needed to adapt to the shape of the food and make sure that it goes down without obstructions, as this could be a reason for suffocation.

The larynx, on the other hand, since it does not participate in any function that requires movement, does not need this muscular nature. In fact, it is simply made up of 9 pieces of cartilage with the function of conducting air from the pharynx to the trachea.