THE TUBES TO LIFE
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By: Haasini Vasudevan
pharynx:
The pharynx helps both the respiratory and digestive functions. The pharynx is also the main part of the throat and is “throat” in Greek. This passageway is shaped like an ice cream cone and leads from the top of the head down to the top of the lungs or larynx and esophagus. Thick fibers attach the pharynx to the base of the skull and connective tissues attach it to surrounding structure. Circular muscles are used so food can go down without air. The longitudinal muscles are used to expand the pharynx while food goes through.
The pharynx has three main parts. The anterior or upper section consists of the nasal pharynx which connects to the back of the nasal cavity. The nasopharynx is connected to the oropharynx by way of the isthmus. The isthmus is cone shaped as well. The oral pharynx connects and starts from the back of the mouth. It continues down the throat and joins at the epiglottis. The epiglottis is a thin flap of tissue that blocks the airway while swallowing and helps to push food down. A triangular shaped structure is built on the wall of the oral cavity and this structure is called the palatine tonsils. These tonsils are capable of getting infected really easily. This is because they are lymphatic tissues that carry fluid. The isthmus is really helpful for operation in case they have to get food into the system but the person cannot swallow or has gotten a mouth infection such as ulcer. The last section is the laryngeal pharynx which helps to stabilize the flow of air down to the lungs.
Two small tubes by the name of Eustachian tubes connect from the middle ears to the nasopharynx. These tubes allow the pressure of the air in the eardrums to be equalized. Earaches and hearing difficulties can be caused by colds which inflames the tubes causing ear aches. Tonsillitis and cancer as well as other types of throat paralysis such as polio, are other medical conditions that are related to the pharynx.
larynx:
The larynx is a hollow tubelike structure that air passes through on its way down to the lungs. It is connected to the windpipe. The other jobs of the larynx it’s to make sure food doesn’t go down to the lungs. While swallowing and to produce sounds as we speak. The larynx also prevents forgiven particles from going down to the respiratory tracts by filtering out the ari through tiny hairs on the walls of the larynx. These hairs then cough out the particles if any are there.
Because the larynx is exposed at the front of the throat, it is composed of hard cartilage tissues that are built as plates. Being connected by muscle fibers makes sure that it maintains its tube like structure. The front set of plates or the thyroid cartilages are replaced by bone cells by the age of twenty.
Covering the larynx is the job of the epiglottis. The epiglottis is a thin tissue flap which is actually very strong. It is the job of the larynx to rise up to the glottis and settle back down after the food has passed.
Instead of the entire larynx being in the same shape, the center portion is a slit-like shape. This occurs twice in the larynx. Both are like large folds in the mucous membrane that line the larynx. The first set at the bottom is known as the false vocal cords. The second is the real vocal cords that produce sounds. Just like a reed on a saxophone or clarinet that vibrates to produce sounds, the air is passed up from the lungs and vibrates against the larynx. This sound that is created is called a raw sound. Then the sound goes up to the upper throat and vibrates against the epiglottis and this creates the full sound. In some languages such as Arabic or Malayalam, the sound goes up to the nasal cavities to produce a nasal sound. Lastly the vibrations go up to the tongue, palate of the mouth, teeth, and lips so the sounds can become words. If the larynx has to be removed due to infections or cancer, then the esophagus will make the sounds but the control of pitch and volume is reduced.