What is Larynx?
In animals, a cartilaginous windpipe is present inside the body. This windpipe connects the larynx to the bronchi of the lungs. This whole system helps in the breathing and speaking process. Let us come to our main question, what is larynx? The larynx is an organ that is involved in the sound production and breathing process. It also protects the trachea from food aspiration. The other name for the larynx is soundbox. The size of the larynx in the adult male is 44mm in length and in females, the length of the larynx is 36 mm. In this article, we have covered the larynx in detail, all the important points about the larynx like larynx function, structure, role, and position have been covered in detail.
Position of Larynx
The larynx lies in the anterior midline of the neck. It extends from the root of the tongue to the trachea. The position in the adult male is from C3 to C6 vertebrae. In adult female and children larynx lies in the C1 to C4 vertebrae position. The diameter of the larynx is around 3mm in the children and around 12 mm in the adults.
Larynx Structure
The larynx structure is composed of nine cartilages. Three cartilages are present in the paired form and the rest of the three cartilages are present in the unpaired form. Let us discuss these cartilages:
Paired Cartilages:
In the larynx structure, the total number of paired cartilage is 6, as they are present in pair (3 * 2 = 6).
Arytenoid Cartilage- These are the cup-shaped cartilages
Corniculate Cartilage- These are horn-shaped cartilages.
Cuneiform Cartilage- These are wedge-shaped cartilages.
Unpaired Cartilages:
In the larynx structure, the total number of unpaired cartilage are three.
Thyroid Cartilage- These type of cartilages are shield shape or v shape.
Cricoid Cartilage- These cartilages occur in a ring form.
Epiglottis Cartilage- This cartilage has a leaf-like structure.
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Let us discuss these human larynx cartilages in detail
Thyroid Cartilage
These cartilages are v-shaped in cross-section. It consists of two laminae; right lamina and left lamina. These two laminas are quadrilateral in shape. The anterior border of both the lamina joins together and forms laryngeal prominence. This prominence is known as Adam's apple. This portion of the lamina, where these are not joined together is known as thyroid notch. This lamina joins at right angles in male and female, they join at 120 degrees. The posterior border of these lamina forms an elongation known as horn or cornua. These are of two types; superior cornua and inferior cornua.
Cricoid Cartilage
The inferior horn of the thyroid cartilage articulates with the cricoid cartilage inferiorly to form a joint. Therefore, this joint is known as a cricothyroid joint. The inferior border of the thyroid cartilage is connected to the cricoid cartilage in the median plane with the help of conus elasticus. The line present between the superior tubercle and inferior tubercle is known as the oblique line.
Three muscles are attached to the oblique line. These muscles are:
Thyrohyoid muscle
Sternothyroid muscle
Thyropharyngeus muscle
The lower border and inferior cornua give insertion to the cricothyroid muscle. The posterior border which is connected to the superior cornua and inferior cornua gives insertion to the palatopharyngeus, salpingopharyngeus, and stylopharyngeus. In the inner position of the thyroid cartilage, three muscles and three ligaments are attached.
The cricoid cartilage is the complete cartilage. It encircles the above present cartilage (thyroid cartilage). It is stronger and thicker than the thyroid cartilage. It articulates superiorly with the arytenoid cartilage.
Role of Larynx Muscle in Human:
It helps in providing tensor strength to the larynx.
These muscles act as an adductor substance.
Posterior cricoarytenoid muscle helps in preventing the collapse. Therefore, it acts as a safety muscle.
These muscles help in opening the inlet.
These muscles help in the closing of the inlet.
Larynx Function
Some of the larynx function are discussed below:
The larynx protects the lower airways.
The larynx in human helps in phonation.
Larynx function in respiratory system is the fixation of the chest.
The larynx helps in the cough reflex.
During the expiration, the vocal cord gets abducted with the help of the larynx muscle.
Did You Know?
The cricoid cartilage forms the foundation stone of the cartilages.
Epiglottis is present in the upper part of the larynx in the anterior wall.
FAQs on Larynx
1. What is the larynx and what is its common name?
The larynx is a specialised organ located in the neck that connects the pharynx (throat) to the trachea (windpipe). It is commonly known as the voice box. Its primary roles are to assist in breathing, produce sound (phonation), and prevent food from entering the lower respiratory tract.
2. What are the main functions of the larynx?
The larynx has several important functions in the body. The main ones include:
- Sound Production: It houses the vocal cords, which vibrate as air passes through them to create sound.
- Airway Protection: The epiglottis, a part of the larynx, acts as a valve that closes the airway during swallowing to prevent food and liquid from entering the lungs.
- Breathing: It provides an open passageway for air to travel from the pharynx to the trachea and lungs.
- Cough Reflex: It helps in forcefully expelling foreign particles from the trachea or bronchi.
3. Where exactly is the larynx located in the human body?
The larynx is situated in the anterior part of the neck. In adult males, it is typically found at the level of the C3 to C6 vertebrae. In adult females and children, it is located slightly higher, usually between the C1 and C4 vertebrae. It sits just above the trachea and below the root of the tongue.
4. How does the larynx protect our airways when we swallow?
The larynx protects our airways through a flap of cartilage called the epiglottis. When you swallow, the entire larynx moves upwards and forwards. This movement causes the epiglottis to fold down and cover the opening of the larynx, known as the glottis. This action effectively seals the windpipe, directing food and liquids into the esophagus instead.
5. What is the main difference between the larynx and the pharynx?
The key difference lies in their function and structure. The pharynx, or throat, is a muscular tube that serves as a passageway for both air (to the larynx) and food (to the esophagus). In contrast, the larynx is a cartilaginous structure that is exclusively part of the respiratory system, responsible for conducting air and producing sound.
6. Is the Adam's apple the same as the larynx?
No, the Adam's apple is not the larynx itself, but a prominent part of it. The Adam's apple is the common name for the laryngeal prominence, which is a bulge formed by the fusion of the two plates of the thyroid cartilage. This cartilage is the largest in the larynx and is typically larger and more prominent in adult males due to hormonal changes during puberty.
7. How do the cartilages of the larynx help it perform its functions?
The cartilages provide a rigid, yet flexible, framework that is crucial for the larynx's functions. The large thyroid and cricoid cartilages keep the airway permanently open for breathing. The smaller, movable arytenoid cartilages attach to the vocal cords, and their movement allows the cords to be tightened, loosened, opened, or closed, which is essential for both sound production and regulating airflow.
8. Why does the pitch of a person's voice change, and what role does the larynx play?
The pitch of a voice is controlled by the tension and length of the vocal cords within the larynx. When intrinsic muscles in the larynx contract, they stretch and thin the vocal cords, causing them to vibrate faster and produce a higher-pitched sound. When the cords are relaxed and shorter, they vibrate more slowly, resulting in a lower-pitched sound. The larynx acts as a precise instrument to make these adjustments.
