Understanding Respiratory System, Voice Physiology & Common Vocal Disorders
Risk Factors
Hypercholesterolemia
Elevated cholesterol levels in blood plasma increase the risk of heart disease. Lipid plaques appear in the vessels, hindering nourishment and causing hardening (atherosclerosis). The plaque grows and restricts blood flow.
When cholesterol is above 200, it’s considered high cholesterol, increasing the risk of cardiovascular disease. Exercise improves cholesterol, but it’s also important to introduce good eating habits: reduced intake of saturated fat, cholesterol, alcohol, and tobacco. Perform regular aerobic exercise.
Hypertension
Blood pressure may increase, and the risk of cardiovascular disease as well.
Causes:
- Atherosclerosis: Diminished caliber of arteries increases resistance to flow, causing pressure to rise.
Weight loss plans, healthy eating, and a healthy lifestyle are recommended. Moderate aerobic and rhythmic exercise is beneficial.
Smoking
Constricts blood vessels, increases platelet adhesiveness, and increases blood pressure.
Obesity
Additional effort of the body and movement is caused by eating junk food. It’s necessary to combine good eating habits, reducing the intake of saturated fat, cholesterol, and sugars, and increase physical activity. Low-impact and low-intensity exercises help burn more calories.
Lack of Activity and Sedentary Lifestyle
Poor nutrition, overweight, and musculoskeletal disuse contribute to health problems. Physical activity has a protective effect on heart disease, controlling weight, controlling hypertension, and so on.
Genetic Bias for Family History
Any history described in blood relatives should be considered. Prevention is possible through proper living habits.
Stress
People who are hyperactive, experience anxiety, hostility, depression, trauma, etc., are at higher risk. Apart from psychological hygiene, physical exercise is recommended.
Breathing
Theory of Speech
- Sufficient in scope and strength. Indispensable master breathing.
- Clear in pronunciation.
- Expressive in intonation, rhythm, intensity, and timbre.
Anatomy
The phono system has three different but related devices:
- Respiratory: Provides air, which when set in vibration becomes sound.
- Vocal apparatus: Air causes vibration, producing sound itself.
- Resonator device: It amplifies and changes the sound produced.
Vocal Apparatus
Larynx: Shaped like a small funnel, whose largest hole communicates with the pharynx above and the trachea below. The larynx originates from the differentiation of the two upper rings of the trachea. The opening that communicates with the pharynx closes during swallowing via the epiglottis. Beneath it is a dilation, the lobby, followed by a narrowing formed by two folds called superior vocal cords. A little further down, there are two closely spaced folds, vocal cords below, that limit a triangular hole, the glottis.
Gas Exchange
Takes place in the lungs through the walls of pulmonary alveoli. In the alveoli, oxygen partial pressure exceeds that of venous blood, and therefore oxygen diffuses into the blood. The exchange is very fast and efficient.
Respiratory Mechanics
Pulmonary ventilation: A process in which gases are exchanged between the atmosphere and the pulmonary alveoli. It is divided into two phases: inspiration and expiration.
If we have air particles in a container and compress them, its pressure will increase. If we increase the space, the pressure will decrease.
For air to enter the lungs, there should be less pressure in the lungs than in the atmosphere, and vice versa if we want the air to escape.
Inspiration: It sets in motion a series of mechanisms to increase lung volume and decrease the pressure, allowing air to enter. The diaphragm muscle contracts and increases the vertical dimension. The contraction of the diaphragm justifies the entry of 75% of air into the lungs, known as diaphragmatic breathing.
Expanding the size of the rib cage: The sternum is elevated while the ribs are elevated, known as thoracic breathing.
Expiration: The reverse is true; pulmonary pressure must be increased for the air to exit. The diaphragm and the inspiratory muscles relax, decreasing lung volume and compressing the air.
Current Volume in Habitual Respiration
At rest or with little physical activity, we conduct small-amplitude breathing. It is the most common type of breathing. It mobilizes a volume of air about a pint. This practice may vary according to circumstances. It’s a mechanism that regulates breathing permanently as required.
Inspiratory Reserve Volume
We can increase the amplitude of the air inlet during inspiration. When an inspiration is broader, we are in what is called the expiratory reserve volume. In this volume, we can breathe more or less completely: we can take a little extra air or inspire as much as possible.
Expiratory Reserve Volume
We may want to exhale more completely. When a tidal amplitude is more important than simply resting expiration, we are in a volume called expiratory reserve volume.
Residual Volume
When you exhale to the maximum, there is always some air in the lungs. This prevents the pulmonary alveoli from flattening and sticking to themselves during expiration. This volume is called residual volume.
All volumes may vary. Some examples:
- Relaxation of the rib cage
- Increase in strength
- Pathology of lung elasticity
Respiratory System
All cells get the energy they need from the oxidative degradation of foods. The oxygen needed to do this, and the carbon dioxide produced, are transported by blood (cellular respiration).
The respiratory system’s fundamental mission is to allow gas exchange between blood and the external environment. It consists of the airways and lungs. A number of muscles are responsible for the expansion and contraction of the ribcage; this phenomenon is called external respiration and pulmonary ventilation.
Larynx, Trachea, and Bronchi
Through the glottis, the air enters the larynx, the upper part of the trachea. They form a tube protected by horseshoe-shaped cartilages to prevent its closure. First in the larynx is the thyroid cartilage, whose prominence forms the Adam’s apple.
The entrance of the larynx is closed to the passage of breath by the epiglottis during swallowing, which prevents food from entering the trachea. The tracheal epithelium moves solid particles into the pharynx. When, due to incomplete closure of the glottis, some portion of food enters the windpipe, it triggers a reflex mechanism that includes certain movements, such as coughing, to expel the particles from the larynx.
The trachea splits into two branches, the bronchi. In the lungs, these tubes branch several times into increasingly smaller caliber tubes called bronchioles, forming the bronchial tree. They end in blind sacs, the lung alveoli, which have thin walls and are vascularized.
Bronchi and bronchioles are reinforced by arches and cartilage plates to keep them open. Among the cartilaginous reinforcements, we can find smooth muscle fibers that change the diameter of the tubes to allow the passage of more air to meet different requirements of the body.
Lungs
A set of bronchioles, alveoli, blood capillaries, and elastic tissue that fills the spaces between them.
Each lung is covered by a membrane, the pleura, which has two layers: the visceral layer, bonded to the surface of the lung, and the parietal layer, lining the chest wall and diaphragm.
Between the visceral and parietal layers, filling the space, is the pleural fluid.
Resonator Device
Composed of the upper chambers of the larynx-pharynx, mouth, and nostrils. They receive and modify the vibration of air produced by the larynx.
Mouth: A cavity whose limits are: lips, cheeks, hard palate that extends to the soft palate and ends in the uvula, and the tongue, after which the larynx is opened.
Of particular importance are two muscles of the face: the orbicularis oris, allowing the lips to form multiple positions and shapes, and the tongue, which can change shape and position inside the mouth by contracting or relaxing, becoming rounded or pointed, and bringing its tip almost anywhere inside the mouth.
Nostrils: Two tubes that pierce the nose.
On the sides are three horizontal ridges called turbinates, which hide small holes that communicate with neighboring bone cavities called sinuses, such as the temporal or maxillary bone sinuses.
Pharynx: Limited in its entirety by soft tissues: the soft palate, with its extension in the uvula, the back of the tongue, and a double glandular mass called the amygdala.
Physiology of Voice
The function of the larynx is phonation, which is the union of the two vocal folds. The glottic closure causes an air lock, forming expiratory subglottic pressure, provided by rhythmic small openings that allow some air leaks favored by that subglottal pressure. This air, passing through the glottic space, vibrates or curls the edges of the vocal folds and forms the fundamental sound or tone.
Acoustic Phonetics
Tone: It is the acoustic frequency, the musical tone. Low frequencies (slow rhythm of the glottis) give a sense of low pitch, while increased speed gives a sense of high pitch.
Intensity: Refers to volume, strong or weak. The intensity is determined by subglottic air pressure while passing through the glottis and the resonance cavities.
Timbre: The relationship between the intensity and frequency of the harmonics of a sound. It is a property of every voice and depends on the harmonic behavior within the resonance structures, allowing us to differentiate voices. Also called the color of the voice.
Resonance
The sound produced in the larynx involves all cavities of the resonator device: the air contained in them changes its vibration according to its characteristics. Since they are different in each person, the natural timbre of the voice varies with each individual. And, as soft cavities can be modified at will, the natural timbre can be varied infinitely. Similarly, various types of occlusion and release of the air column will produce various ways to start or stop the sound.
The Most Frequent Alterations of the Vocal Folds
The Nodule
It is situated at the free edge of one of the first thirds of both vocal folds.
Nodules are hard lumps that, during phonation, allow lateral air leakage, resulting in loss of vocal intensity, a hoarse voice, and low frequency.
Polyps
Soft-sided formations, often originating in the anterior third of the vocal folds.
Surgery is customary.
Symptoms: Air leakage, loss of sound intensity, shortness of breath, broken voice, and so on.
Laryngitis
An inflammatory process that affects the larynx. When it affects the vocal folds, it may range from mild to acute or even to aphonia.
There are irritants to the larynx and airway in general: tobacco, alcohol, irritating dust, sudden temperature changes, air conditioning, heating, polluted environments, and so on.
Functional pharyngitis is caused by a bad vocal mechanism. The concentration of the voice sound at the level of the larynx leads to persistent inflammation of the vocal folds.
Pharyngitis
An inflammatory process characterized by pain in swallowing, dryness, and congestion. It causes mild dysphonia and is functional in origin.