The Changes Of Aging In The Human Body

Aging causes changes in the body with or without the presence of disease processes. Tissue elasticity reduces over time and fat replaces space that was once occupied by the muscle (Corbin-Lewis et al., 2005). Similar changes can be seen in the oropharyngeal component during normal aging. With age, the mucosa in the oral cavity becomes more keratinized or fibrous (Corbin-Lewis et al., 2005). The tongue becomes smoother and starts to atrophy. The temporomandibular joint starts to lose range of motion during normal aging and there is a decrease in sensation in the areas of the oral, pharyngeal and laryngeal areas (Corbin-Lewis et al., 2005). Additionally, the larynx becomes calcified and the cartilages become less compliant as individuals age (Corbin-Lewis et al, 2005). Aging in normal, healthy individuals can have specific effects on the stages of the swallow.
For the oral phase there are several processes that happen to the muscles during aging.
These changes include the slowing or decreased movement of the tongue, a reduced strength in mastication muscles, increased oral transit times and the bolus is positioned more posteriorly in the oral cavity (Corbin-Lewis et al., 2005). For the pharyngeal stage, aging results in a swallow response that is triggered lower in the pharynx, delayed anterior movement of the hyoid, progressive pharyngeal contraction is slowed and longer swallowing apnea duration (Corbin-Lewis et al., 2005). The UES opening size decreases and the UES is less flexible with aging(Corbin-Lewis et al.,
2005). Respiration The mechanics of breathing can be characterized by the type of breathing an individual is partaking in. These types of breathing are described as quiet breathing, forced breathing and speech breathing. Passive and active forces are utilized together to breathe. When the diaphragm contracts, the rib cage expands. Due to the pleura linkage of the visceral and parietal pleura the lungs and alveoli expand. The air pressure in the alveoli is low compared to the atmosphere, so air comes rushing in (quiet inhalation, muscles in Appendix B). Then the diaphragm and ribs start to recoil. The air pressure in the alveoli is higher than that of the atmosphere so air comes expelling out which is (quiet exhalation). Quiet breathing occurs during the oral prep, oral transit and esophageal phases of swallowing. However, during the swallow the airway closes for a bit and this moment of airway closure is called apnea (Logemann, 1997), which takes place during the pharyngeal stage (Logemann, 1997). When the muscles are activated to deepen an inhalation or when abdominal muscles are used to extend a breathe forced breathing occurs (muscles in Appendix B). While the basic function of the respiration system is to maintain an appropriate exchange of carbon dioxide and oxygen throughout the body, this system is necessary for speech (Bhatnagar, 2013). The breathing system contributes to characteristics of speech like loudness, pitch, division, syllable and segmentation all while ventilating for gas exchange (Hixon, Weismer & Hoit, 2014). A deep inspiratory breath needs to take place to produce a long utterance in speech. The alveolar pressure will rise abruptly and remain steady during the speech utterance, then will fall abruptly when the utterance stops (Hixon et al., 2014). Speech breathing requires muscles of forced inhalation and forced exhalation. Further, a “checking” action occurs from the muscles listed in Appendix B, to hold the rib cage in an expanded position.
Conclusion
In conclusion, the oropharyngeal structure and the swallowing mechanism need to be examined to understand a normal and abnormal swallowing. Variations occur from individual to individual in regard to anatomical structures, however a speech language pathologist needs to be able to distinguish what is on the spectrum of normal versus abnormal. By examining the different phases of the swallow, the development and aging processes of the oropharyngeal phase and the respiration mechanics of breathing, a complete picture of the components of swallowing come into play.