1- Physiology of speechPresented by : Amit Kumar Maurya Hem Prakash Singh
Physiology of speech : -• Speech requires movement of sound waves through the air. Speech itself is air that is moved from the lungs through a series of anatomic structures that mold sound waves into intelligible speech.• This capacity can be accomplished in any volume from a soft whisper to a loud shout by varying the force and volume of air expelled from the lungs. All languages are spoken by the same mechanism, though the words are different and require different usages of the anatomy.
• Physiology of respiration• Purpose of respiration• Description of respiratory movements• Types of respiration• Method of respiratory analysis
Physiology of respiration• Respiratory physiology has had a long history . With remarkable advance in this century . Hippocretes (460-377 b.c) suggested that the purpose of breathing is to cool the heart.
The respiratory passage:• Includes, in descending order, the nasal & oral cavities, the pharynx, larynx, trachea & bronchi- forms a continuous passage leading from the exterior to the lungs.• The nasal oral & pharyngeal cavities are intrinsic parts of breathing mechanism and also essential organs of articulation & resonance.• The larynx is a modification of the uppermost tracheal cartilages
2- Bony thorax :• Vertebrae and vertebral column• Ribs and their attachment to vertebral column• Sternum• Clavicle• Scapula• Pectoral girdle• Ilium• Pubic bone• Pelvic girdle
3- Muscles of respiration• Diaphragm• Accessory muscles of inspiration• Accessory muscles of expiration• Muscles of postural control
TRACHEA:• Extends from the larynx at the level of C6 to the bronchibelow, which is at the level of the top of the T5.• Flexible tube.• 11 to 12 cm in length• Its composed of a series of 16 to 20 hyaline cartilagerings open in posterior aspect placed one above the other,separated by a small space that is filled by fibro elasticmembrane.• diameter of tracheal rings is from 2 to 2.5 cm.
• Intervening space between the ends of the trachealrings is occupied by fibrous tissue & smooth msls• The Ist tracheal cartilage is slightly larger than others& it is connected with the inferior border of the cricoidcartilage of larynx by cricotracheal ligaments.• Last cartilage of trachea bifurcates giving rise to mainstem bronchi.• At the level of bifurcation ( carina ), it divides into Rt& Lt mainstem bronchi which serve Rt & Lt lungs.
• Fibrous membrane of trachea consists of 2 layers, 1 ofwhich passes over the outer surface of cartilagenous ringswhile other passes over the inner surface.•In the space between the rings, the 2 layers blend to forma single intratracheal membrane which connects thetracheal rings one with another.• The smooth msl which is found in the space between thetracheal rings consists of an outer longitudinal layer & aninner transverse layer.•Mucous membrane which lines the trachea is continuousabove with that of larynx and below with that of bronchi
BRONCHI:• extends from trachea to lungs where they arborize toform bronchial tree.•Divided into: mainstem bronchi lobar/ secondary bronchi segmental/ tertiary bronchi•Mainstem bronchi connect trachea to lungs and the pt atwhich they enter is called hilum•R bronchus is larger in diameter, shorter in length andmore in direct line with trachea than the L.
• Composed of cartilagenous rings bound together by fibro elastic tissue.• Invested by smooth msl fibers lined by psuedostratified ciliated columnar epithelium, walls contain elastic and glandular tissue.• R bronchus is divided into 3 sec bronchi.• sec bronchi is divided into 10 ter bronchi.• L bronchus is divided into 2 sec bronchi, from which 8 ter bronchi arises.
BRONCHIOLES:• Ter bronchi divide repeatedly, becoming smaller• In adults 24 generation of divisions which compromise the bronchial tree, but the combined cross sectional area of any sub division is greater than cross sectional area of parent division• Final division of bronchi give rise to bronchioles, 1mm/less in diameter.• Repeated division give rise to terminal bronchioles which communicate with the alveolar ducts and open into minute air sacs of lungs.
ALVEOLI:• Walls of terminal bronchioles & air sacs are pitted with 7,000,000 small depressions called alveoli.• Small pits- alveolus , so alveoli in lungs are called alveoli pulmonis• Lined by a single layer of epithelial cells resting on a thin basement membrane called Type I cells & phagocytic cells
LUNGS:• Located in thoracic cavity and largely occupy it.• They are two irregular cone shaped structures composed of spongy porous highly elastic materials that contains smooth muscles fibres.• It lie freely within their pleural cavities and attached to the body only by their roots and pulmonary ligaments.• Roots are formed by the bronchi, pulmonary arteries and veins, the pulmonary plexus of nerves and the lymphatic vessels, encircled by connective tissues that contributes to the media stinum.
• Ms is bounded on each side by lungs and pleural sacs.• Its divided into anterior, middle, posterior and superior MS.• anterior MS contains mammalary vessels and lymph nodes.• Middle MS contains heart which is surrounded by a closed membranous sac called pericardium.• Posterior MS contain part of esophagus and trachea, some important nerve tracts and blood vessels that supply the head.
• R lung is larger than L, but shorter and broader.• Heart occupies much of the left side of thorax.• Each lung has an apex, base, coastal and mediastinal surface in addition to anterior, inferior and posterior borders.• Apex extends beyond upper limits of thorax, into the root of neck to about 2.5 to 5 cm above the sternal end of first rib.• Base is broad and concave confirms to the thoracic surface of diaphragm.
LOBES:• R lung is partially divided into three lobes by two fissures.• Oblique fissures separates superior from inferior lobe.• Horizontal fissure give rise to small middle lobe.• L lung divided by oblique fissure into superior and inferior lobe, no horizontal fissure.PLEURA:• In a surface of thoracic cavity, thoracic surface of diaphragm and medaistinum are lined with an air tight membrane called parietal or coastal pleura. Its continuous with the visceral pleura by means of reflections at the root of tongue.
• A sleeve of pleura encloses the bronchi and pulmonary blood vessels which forms a fold called the pulmonary ligament.• Lungs are encased in visceral pleura and thoracic linings are parietal pleura.• Pleura is composed of a single layer of squamous mesothelial cells resting upon a delicate tissue membrane.• Its highly vascular, contain lymphatics and nerves.
2- Bony thoraxVertebrae and vertebral columnRibs and their attachment tovertebral columnSternumClavicleScapulaPectoral girdleIliumPubic bonePelvic girdle
Vertebral column :• The vc of the adult is a flexible . Supports the head and encloses the spinal cord.• There are 33 bones or vertebrae in the spine. The vertebral column has 5 divisions.• 7 cervical vertebrae in the neck (C1 - C7)• 12 thoracic vertebrae in the upper back corresponding to each pair of ribs (T1 - T12)• 5 lumbar vertebrae in the lower back (L1 - L5)• 5 sacral vertebrae are fused together to form 1 bone called the sacrum (S1 - S5)• 4 coccygeal vertebrae that are also fused to form the coccyx or tailbone.• Each vertebra consists of two essential parts - an anterior solid segment or body, which is largest part of the body and a posterior segment arch.
Sternum :• The sternum is a prominent mid-line structure located on the anterior , superior thoracic wall.• It consists of 3 parts : the manubrium, the body, and the xiphoid process.• The uppermost segment of the sternum is known as the manubrium which is a quadrilateral plate, somewhat wider above than below.• The body/corpus of the sternum is long and narrow.• The inferior border of the body articulates with a small process called the xiphoid process.
Ribs 12 pairs of ribs complete the rib cage. The ribs are designated by numbers. The first seven ribs articulate posteriorly with the vertebral column, course obliquely downward and at their lowest point give rise to costal cartilages which course upward to articulate with the sternum. The rib cage becomes progressively larger from the first through the seventh or eighth ribs, and then progressively smaller to the twelfth, so the thoracic framework takes on a barrel-like appearance The ribs become progressively more oblique from ribs 1 through 8 or 9, and then obliquity decreases.
3- Muscles of respirationDiaphragmAccessory muscles of inspirationAnterior thoracic muscle ofinspirationAccessory muscles of expirationPosterior thoracic muscles ofinspiration
MUSCLES IN RESPIRATION DIAPHRAGM• The diaphragm is a major muscle of ventilation. It is a dome shaped musculor fibrous partition located between the thoracic cavity and abdominal cavity.• It is composed of 2 separate muscles known as the right and left hemi- diaphragms. Each hemi-diaphragm arises from the lumbar vertebrae, the costal margin and the xiphoid process.• The 2 muscles then merge at the mid-line into a broad connective sheet called the central tendon.• When stimulated to contract, the diaphragm moves downward and the lower ribs move upward and outward.• This action increases the volume of the thoracic cavity which, in turn, lowers the intra-pleural and intra-alveolar pressures in the thoracic cavity. As a result gas from the atmosphere flows into the lungs.• During expiration, the diaphragm relaxes and moves upward into the thoracic cavity. This action increases the intra-alveolar and intra-pleural pressures, causing gas to flow out of the lungs.
Accessory muscles of inspiration• The accessory muscles of inspiration are not involved during normal quiet breathing.• These muscles play a role during exercise, during the inspiratory phase of cough or sneezing, or in a pathologic state (asthma).• The accessory muscles of inspiration are those muscles that are recruited to assist the diaphragm in creating a sub- atmospheric pressure in the lungs to enable adequate inspiration . The major accessory muscles of inspiration are : Scalene muscles Sternocleidomastoid muscles Pectoralis muscles Trapezius muscles External intercostal muscles
Scalene muscles• 3 separate muscles that function as a unit. They are known as the anterior, the medial and the posterior scalene muscles. They originate on the transverse processes of the second to the sixth cervical vertebrae and insert into the first and second ribs.• The primary function of these muscles is to flex the neck. When used as accessory muscles for inspiration, they elevate the first and second ribs, an action that decreases the intra-pleural pressure.
Sternocleidomastoid muscles• The sternocleidomastoid muscles are located on each side of the neck. Originate from the sternum and clavicle and insert into the mastoid process and occipital bone of the skull.• When the sternocleidomastoid muscles function as an accessory muscle of inspiration, the head and neck are fixed by other muscles and the sternocleidomastoid pulls from its insertion on the skull and elevates the sternum. This action increases the anteroposterior diameter of the chest.
Pectoralis Major Muscles The pect or al i s m or m aj uscl es ar e pow f ul , f an-shaped er m uscl es l ocat ed on each si de of t he upper chest . The or i gi nat e f r omt he cl avi cl e and t he st er numand i nser t i nt o t he upper par t of t he hum us. W f unct i oni ng as er hen accessor y m uscl es of i nspi r at i on, t hey pul l f r om t he hum al i nser t i on and er el evat e t he chest , r esul t i ng i n an i ncr eased ant er opost er i or di am er et• Tr apezi us Muscl es The t r apezi us M uscl es ar e l ar ge, f l at , t r i angul ar m uscl es t hat ar e si t uat ed super f i ci al l y i n t he upper back and t he back of t he neck. They or i gi nat e f r omt he
Anterior thoracic muscles of inspiration• External intercostal muscles :• Origin : inferior surface of ribs 1 to 11• Insertion : upper surface of ribs• The external intercostal muscles contract during inspiration and pull the ribs upward and outward, increasing both the lateral and anteroposterior diameter of the thorax. This action increases lung volume and prevents retraction of the intercostal space during an excessively forceful inspiration.
Internal Intercostal Muscles The Internal Intercostal Muscles run between the ribs immediately beneath the external• Its arise from the inferior border of each riband insert into the superior border of the rib below.• Anteriorly, the fibers run in a lateral and downward direction.• Posteriorly the fibers run downward and in a medial direction.• The Internal Intercostal Muscles contract during expiration and pull the ribs downward and inward, decreasing both the lateral and anteroposterior diameter of the thorax. This action decreases lung volume and offsets intercostal bulging during excessive expiration.
Accessory muscles of expiration1-Rectus abdominals muscle: Commonly known as "abs“ is a paired muscles running vertically on each side of the anterior wall of the human abdomen. There are two parallel muscles, separated by a midline band of connective tissue called the white line. It extends from the pubic crest inferiorly to the xiphoid process and lower costal cartilages superiorly. When contracted the rectus abdominis muscle assist in compressing the abdominal contents. This compression in turn pushes the diaphragm into the thoracic cage., thereby assisting in exhalation.2-External oblique abdominis: This muscles are broad ,thin muscles located on the anterolateral sides of the abdomen. They are the longest and most superficial of all the anterolateral abdominal muscles. They arise by 8 digitations from the lower 8 ribs,
Internal Oblique Abdominis Muscles• Its located in the lateral and ventral parts of the abdominal wall directly under the external Oblique Abdominis muscles, its arise from the inguinal ligament, the iliac crest and the lower portion of the lumbar aponeurosis. they insert into the last 4 ribs and into the linea alba.• The Internal Oblique Abdominis muscles also assist in exhalation by compressing the abdominal contents and in pushing the diaphragm into the thoracic cage
Transverses Abdomen Muscles• Its found immediately under the internal oblique abdominis muscles. Which arise from the inguinal ligament, and the lower 6 ribs and insert into the linea alba. When activated, they also help to constrict the abdominal contents.• When all 4 pairs of accessory muscles of exhalation contract, the abdominal pressure increases and drives the diaphragm into the thoracic cage. As the diaphragm moves into
Posterior thoracic muscles of inspiration:• Levatores costarum• Serratus posterior
Function of Respiratory System:• Primary function is to obtain oxygen for use by bodys cells & eliminate carbon dioxide that cells produce• Pathway of air: nasal cavities (or oral cavity) > pharynx > trachea > primary bronchi (right & left) > secondary bronchi > tertiary bronchi > bronchioles > alveoli (site of gas exchange)
Major Functions of the Respiratory System• To supply the body with oxygen and dispose of carbon dioxide• Respiration – four distinct processes must happenPulmonary ventilation – moving air into and out of the lungsExternal respiration – gas exchange between the lungs and the bloodTransport – transport of oxygen and carbon dioxide between the lungs and tissuesInternal respiration – gas exchange between systemic blood vessels and tissues
Path Taken by Inhaled Air• The composition of air that we breathe in is:1. Nitrogen - 78%2. Oxygen - 21%3. Carbon dioxide - 0.03 - 0.04%4. Hydrogen - traces5. Noble gases - traces• Thus the air naturally contains more oxygen than carbon dioxide.• This oxygen-rich air is taken in by the nostrils. In the nasal cavity, it is filtered by the fine hair.• The cavity also has a rich supply of blood vessels that keep the air warm.
Cont….• This air then enters the pharynx, then the larynx and then into the trachea.• The trachea and the bronchi are lined with ciliated epithelial cells and secretory cells (goblet cells).• The secretory cells secrete mucus which moistens the air as it passes through the repiratory tract and also trap any fine particles of dust or bacteria that have escaped the hairs of the nasal cavity.• The cilia beat with an upward motion such that the foreign particles along with the mucus is sent to the base of the buccal cavity from where it may be either swallowed or coughed out.
Cont…Cilia on the Inner Lining of the Wind PipeBeating to Propel a Particle OutsideThe air from the bronchus then enters the bronchioles and then the alveoli. Thealveoli form the respiratory surface in the humans.
Gaseous Exchange• The capillaries lining the alveoli have impure blood which has low concentration of oxygen.• So, the oxygen from the air easily diffuses into the blood through the thin barrier of the alveolus wall.• Similarly since the concentration of carbon dioxide is quite high in the blood, the gas easily diffuses out into the alveolar space.• From here, the air that has comparatively more concentration of carbon dioxide than the air that entered it, leaves the lungs.• Note: Emphysema is condition wherein the area for gaseous exchange in lungs gets reduced, This occurs commonly in heavy smokers.• The walls separating alveoli breakdown resulting in abnormal alveoli with lesser area. Due to this condition the heart has to pump more blood. This may lead to a strain on the heart causing heart failure.
Gaseous Exchange in the Alveolus of Man
APPLICATION OF BOYLE’S LAW:• Robert Boyle, a British physicist, discovered that volume & pressure are inversely related, i.e. V =1/p.• Therefore, increasing the volume of an enclosed space will decrease the air pressure within it.• Boyle’s law – the relationship between the pressure and volume of gases P1V1 = P2V2 P = pressure of a gas in mm Hg V = volume of a gas in cubic millimeters Subscripts 1 and 2 represent the initial and resulting conditions, respectively
2- Purpose of respiration1- The purpose of the respiratory system is to bring oxygen into the blood so it can distribute it to the body cells. It also turns oxygen into nutrients and removes carbon dioxide from the body. To supply oxygen to the body. To eliminate carbon dioxide in the body. To regulate the bodys pH balance.
Cont..2- The purpose of respiration is to store energy released from food molecules so it can be used by the cell. It increases the flow of blood to individual cells. It converts energy in nutrients to ATP in the presence of oxygen and generates carbon dioxide as a waste product so that you can accomplish work.• It causes the buildup of lactic acid.• It increases the heart rate.
Cont..3- Respiration circulate, and metabolism all works together , the main purpose of respiration is to provide oxygen for the body’s cells .• Oxygen is used by cells for the breakdown of nutrients, an activity that is necessary to supply energy to the cells and the body .• Without oxygen, cells are unable to function properly . Oxygen deprivation even for only a few minutes , can cause the brain and the heart to stop functioning, which can lead to death
3- Types of respirationRespiration is the act of breathing :Breathing consists of two phases :• Inspiration• Expiration.
DifferenceInspiration ExpirationDiaphragm descends Diaphragm ascendsRibcage elevates and/or expands Ribcage descends and/or contractsIncreased intra-thoracic volume Decreased intra-thoracic volumeDecreased intra-thoracic pressure Increased intra-thoracic pressure‘High pressure exterior air flows ‘High pressure air in lung flowsinto low pressure lung. out toward low pressure exterior
• How breathing differs for quite and speech?
Inspiration For quite breathing:• Thoracic enlargement leads to inspiratory flow; the enlargement takes place in three dimensions-vertical, anteroposterior, transverse.• Vertical enlargement takes place by lowering the base of the thorax (diaphragm).• Antero-posterior and transverse movements are more complex-ribs attach to the vertebral column posteriorly, from which they slope below and forward towards the front of the thoracic cage.• Upon elevation the ribs go through two types of movement: which are compared to the ‘pump handle’ and ‘raising bucket handle’ movements.
Cont…• In pump handle movement the front ends of the ribs move up and forward along with the sternum, the result being enlargement in the antero-posterior diameter of thorax.• Bucket handle amounts to an outward eversion (rotation) of each rib around an imaginary line joining its two ends. This action results in the widening of the thorax transversely, the extent of the increase being greater in the lower than the upper thorax because the lower ribs swing through arcs larger imaginary circles (siebeas, 1966).• For quite inspiration (or inhalation), the medulla automatically sends neural impulses via the spinal cord to the pertinent thoracic muscles. Several nerves emerge from the spinal cord at the level of the neck (Cervical nerves) & join to form a nerve bundle known as phrenic nerve.
Cont…• The phrenic nerve innervates diaphragm, the convex sheet of muscle fibers that separates the thoracic & abdominal cavities.• When nervous stimulation is sufficient to cause a contraction of the diaphragm, the muscle fiber shorten pulling the central part downward toward the edges , which are attached to the lower ribs. The effect is to lower & flatten the diaphragm to some effect.• As the diaphragm forms the floor of the thoracic cavity, thoracic volume is increased vertically as the floor is lowered.• The abdomen protrudes upon inspiration because of the downward pressure of the diaphragm upon the abdominal contents.• At the same time that the diaphragm is lowering, nerve impulses are transmitted via the nerves emerging from the spinal cord at the level of the chest (thoracic nerves) to innervate muscles that run between the ribs.
Cont…• During inspiration, the external intercostal muscles & the section of the internal intercostals that lies between the cartilaginous portions of the ribs contract to elevate the ribs.• This action is aided by the twisting of the cartilage. Elevation of the ribs is thus produced by the joint efforts of the external intercostal muscles & the interchondral parts of the internal intercostal muscles aided by the slight rotation of the cartilage.• As the volume within the thorax increases with corresponding lung volume increase, the air pressure inside the lungs decreases relative to the atmospheric pressure outside. Consequently, air from the outside moves to the area of less density or lower pressure within the lungs.
For Speech breathing:• Speech Breathing is the regulation of the exhaled airstream to support the processes of phonation and articulation, to ensure the timely inspiration of air to support life and next speech event.• There are differences between inspiration during quiet breathing & inspiration for speech breathing. 1) The volume of air inspired for speech sounds is generally greater than that inspired during quiet breathing especially if the speaker knows that he is going to generate an utterance that is long and loud(or both). To accomplish the inspiration of a grater volume of air, the diaphragm & the intercostal muscles can be augmented by any of several muscles capable of sternum & rib elevation:
Cont… The sternocleidomastoid, the Scalenus, the subclavius, the pectoralis major, & minor in front, The Serratus Anterior muscle at the sides, & The levatores Costarum muscles, Serratus posterior muscle & latttismus dorsi muscle at the back. A second difference is in the degree of automaticity. .We breathe in & out, day & night, conscious & unconscious , & the process is under reflexive control, with the rate & depth of volume change dependent upon need.3) Inspiration for speech comprises less of the total respiratory cycle than during quiet breathing.• During quiet breathing, the ratio is roughly 40% inspiration & 60% expiration while for speech it is about 10% inspiration & 90% expiration.
Expiration For quite breathing:• When the glottis is open for inspiration, air from outside enters the lungs .When the inspiratory muscle effort is complete, there is a moment of equalized pressure. The pressure in the lungs is equal to the atmospheric pressure. At a relatively high thoracic volume, however, a large inspiratory effort is required to maintain the volume. If the inspiratory muscles are made to relax, then the air would suddenly rush out because of three passive forces:1. The elastic recoil of the lungs & the rib cage,2. Torque (the force of untwisting of the cartilages next to the sternum),3. Gravity, which may aid in lowering the rib cage.• These three passive forces suffice to decrease the volume of the rib cage & lungs.• According to Boyle’s law, the decrease in volume increases the pressure within, causing air to flow out. For inspiration, an increase in thoracic volume causes a decrease in pressure. For expiration, a decrease in thoracic volume causes an increase in pressure.• In quiet expiration, the exchange of air is small (approximately 0.5 liter). With deeper breaths like those that accompany exercise, the volume of air exchange increases.
For sustained phonation:• The passive expiratory forces of elasticity, torque, & gravity are not sufficient by themselves to support singing or speaking. Expiration during phonation then differs from those during quiet breathing, & expiration during speech differs from both.• In order to maintain a constant pressure to produce a note sung at a constant intensity, the passive recoil force of the rib cage-lung coupling is used as a background force that is supplemented by active muscle contractions, first of the inspiratory muscles, then of the expiratory muscles.• If a singer permitted expiratory forces to act unaided, the lungs would collapse suddenly & the note could not be sustained. The purpose of the active inspiratory forces is to slow down the outflow. The expiratory muscle forces are recruited later to further decrease thoracic size below the limits set by elastic recoil.
For Speech• The continued action of the inspiratory muscles to check the rate of expiration seen in sustaining a tone is also evident during expiration for speech. The expiratory muscles are innervated by spinal nerves. The thoracic nerves (T1-T11) innervate the internal intercostal muscles, the interosseeous portion of which contract to shorten the distance between the ribs by depressing them, thereby reducing thoracic volume. The abdominal muscles are active in extended expiration as their contraction presses in upon the abdominal contents forcing the diaphragm up. The chief abdominal muscles used in expiration are rectus abdominis, the external & internal Oblique, & the transversus abdominis.• Expiration for speech differs from expiration for a sustained tone by many factors:• During Speech, intensity is constantly changing because certain sentences, phrases, words, & Syllables are given certain emphasis. In order to increase the intensity of the speech sound, the speaker must increase the sub glottal pressure. The activity of the abdominal muscles increases in order to supply the added respiratory force needed for utterances that are heavily stressed or long in duration.
Cont…• Increases in syllable duration, fundamental frequency, & Intensity may each accompany the production of stressed syllables. The intensity of the voice is primarily controlled by sub glottal pressure, & it increases as a function of between the 3rd & 4th power of the sub glottal air pressure. I =P(sub)3 or Ps4• As the formula above indicates, a small change in pressure generates a large change in intensity. If you double the sub glottal pressure, the intensity will increase between 8 & 16 times, a 9 to 10 db increase in sound intensity.• Another difference between expiration for speech & for either sustained phonation or for quiet breathing is that phase groups determine the duration of the expiration. In saying “I’m nobody. Who are you? Are you nobody too?” a speaker might use one expiration or perhaps two. The break for the text is partly determined by the text. Variations in expiratory duration depend on what is spoken. It results in relatively long durations of the expiratory part of the respiratory cycle.
Cont…• A speaker who wants to finish a long phrase without interruption often contracts expiratory muscles, using some of his expiratory reserve volume, even at the expense of his comfort.• A final difference between quiet breathing & breathing for speech is the volume of air expended. During normal relaxed breathing we only use 10% of our vital capacity. For e.g.: We may inhale up to 50% of VC & then exhale to 40%.• In conversational speech, Hixon reports that we typically inspire up to roughly the 60% of vital capacity. & do not take another breathe until we have reached an appropriate stopping place near a resting expiratory level of about 30-40% of vital capacity.. Therefore, we use only about 25% of our vital capacity for conversational speech. During loud speech, we use 40% of vital capacity, the expiratory phase going from 80%-40% of vital capacity.
4- Description of respiratory movements The specific characteristics of the speech breathing pattern may vary across individuals and theses differences may be quite stable. These patterns are sometimes called Ventillatory /Respiratory. There are 4 main types of breathing movements :1. Costal or chest breathing,2. Diaphragmatic or abdominal breathing,3. Clavicular breathing,4. Circular breathing
COSTAL OR CHEST BREATHING• This type of breathing is characterised by an outward, upward movement of the chest wall.• In chest breathing the expansion is centred at the midpoint and consequently it aerates the middle part of the lung most.• Since the lower part of the lung is most abundantly perfused with blood, we have that ventilation perfusion mismatch.• Thus during resting periods chest breathing is less efficient.• Chest breathing also requires more work to be done in lifting the rib cage, thus the body has to work harder to accomplish the same blood gas mixing than with diaphragmatic breathing, and the greater the work, the greater the amount of oxygen needed, which results in more frequent breaths.• Chests breathing is useful during vigorous exercise but it is quite inappropriate for ordinary, everyday activity.
ABDOMINAL OR DIAPHRAGMATIC BREATHING• The principal muscle involved in abdominal breathing is the diaphragm, a strong dome-shaped sheet of muscle that separates the chest cavity from the abdomen.• When we breathe in, the diaphragm contracts and pushes downwards, causing the abdominal muscles to relax and rise.• In this position, the lungs expand, creating a partial vacuum, which allow air to be drawn in.• When we breathe out the diaphragm relaxes, the abdominal muscle contract and expel air containing carbon dioxide. Of the two major types of breathing, diaphragmatic breathing is the most efficient because greater expansion and ventilation occurs in the lower part of the lung where the blood perfusion is greatest.
Cont….• Judson and Weaver (1965) point out that changing relationship with age of the angle between the ribs and the axis of the body in the fetus and at the birth it average 90 degree.• At 4ys of age it’s 82 degree.• In adults 64 degree.• The horizontal disposition of the ribs in a baby makes costal breathing to enlarge the thorax less efficient and explains why babies breathe in a predominantly abdominal manner.
CLAVICULAR BREATHING• Clavicular breathing is only significant when maximum air is needed and the body’s need for oxygen is very great. .• The name is derived from two clavicles or collar bones which are pulled up slightly at the end of maximum inhalation, expanding the very top of the lungs.• Sternocliedo-mastoid muscle would be particularly active in this breathing.• Individuals with neurologic or lung disease such as patients with asthma or chronic bronchitis, may use this adaptive strategy to compensate for impaired function• It’s also called as paradoxical breathing because of the tendency for the abdomen to be drawn inward during inspiration instead of expanded slightly outward.
Circircular Breathing:• Musicians who play wind instruments such as the above /clarinet are often required to sustain a note for considerably longer than is possible from using expiratory airflow on a single breathing alone.• A talented musician overcomes this problem by using this strategy. It enables the individual to replenish the volume of air in his or her lungs by inhaling all the while continuing to blow air out of all the mouth and into the wind instrument, there by breathing and maintaining the musical note simultaneously.• Here they are adjusting distribution of volume of air in your mouth by using your cheek muscle, breathing all the while through the nasal passages by way of the opening velopharyngeal port.
Cont…• We can maintain breath by lowering velopharyngeal port, thereby sealing off the oral cavity from rest of vocal tracts Musicians uses their cheek muscle to squeeze the impounded air out of their mouth and thru the instrument.• After inhalation and subsequent increase in lung volume the velopharyngeal port is raised and the air is exhaled through oral cavity in to the mouth.• Although as SLP’s we are concerned with the breathing system primarily as a power source for voice and speech production, the metabolic ventillatory demand of body supersede its communicative function.• Too much oxygen in blood can result in dizziness, blurred, numbness and tingling. Too little oxygen can cause impaired cellular respiration .Tissue damage and ultimately death
Lung VolumesTidal Volume (TV) The volume of air inhaled and exhaled during any single expiratory cycle (an inhalation followed by an exhalation) is known as tidal volume.Inspiratory Reserve Volume (IRV) The quantity of air which can be inhaled beyond that inhaled in a tidal volume cycle is called inspiratory reserve volume. In a state of rest (quiet tidal breathings), inspiratory reserve volumes vary anywhere from about 1500 to about 2500 cc.
Expiratory Reserve Volume (ERV) The amount of air that can be forcibly exhaled following quiet or passive exhalation is known as expiratory reserve volume or resting lung volume (RLV). Expiratory reserve volume usually amounts to about 1500 cc and may go as high as 2000 cc in a young adult.Residual Volume (RV) The quantity of air that remains in the lungs and airways even after a maximum exhalation is called residual volume. Regardless of the depth of inhalation, approximately 150cc of our residual air neither contributes oxygen to the blood nor receives carbon dioxide from it. It is called dead air, and remains in the nasal cavities, larynx, trachea, bronchi, and bronchioles, or collectively, the dead-air spaces.
Minute Volume = Rate (breaths per minute) X Tidal Volume (ml/breath)Rate of respiration at rest varies from about 12 to 15 bpm. Tidal volume averages 500 ml Assuming a rate of 12 breaths per minute and a tidal volume of 500, the restful minute volume is 6000 ml. Rates can, with strenuous exercise, increase to 30 to 40 bpm and volumes can increase to around half the vital capacity.
LUNG CAPACITIESInspiratory Capacity (IC) The maximum volume of air that can be inhaled from the resting expiratory level is called the inspiratory capacity. Itcan be measured directly with a spirometer and is equal to tidal volume plus inspiratory reserve volume.Vital Capacity (VC) The maximum volume of air that can be forcefully expelled from the lungs following a maximal inspiration. It is the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume. In adult males it ranges from 3500 cc to 5000cc.
Functional Residual capacity (FRC) The quantity of air in the lungs and airways at the resting expiratory level is known as functional residual capacity. It is computed by taking the sum of expiratory reserve volume and residual volume. In young adult males functional residual capacity amounts to about 2300 cc.Total Lung capacity (TLC) The quantity of air the lungs are capable of holding at the height of a maximum inhalation is logically known as total lung capacity and is equal to the sum of all lung volumes.
Pressures of the respiratory systemThere are 5 specific pressures for speech and non-speech functions. Alveolar pressure ,intrapleural pressure, subglottal pressure, intraoral pressure and atmospheric pressure.Alveolar Pressure• This is the pressure, measured in cm H20, within the alveoli, the smallest gas exchange units of the lung. Alveolar pressure is given with respect to atmospheric pressure, which is always set to zero. Thus, when alveolar pressure exceeds atmospheric pressure, it is positive; when alveolar pressure is below atmospheric pressure it is negative.• Alveolar pressure determines whether air will flow into or out of the lungs. When alveolar pressure is negative, as is the case during inspiration, air flows from the higher pressure at the mouth down the lungs into the lower pressure in the alveoli. When alveolar pressure is positive,which is the case during expiration, air flows out. At end-inspiration or end-expiration, when flow temporarily stops, the alveolar pressure is zero .
Intrapleural pressure (Ppl) Intrapleural pressure (also called intrathoracicpressure) is the pressure exerted outside the lungs within the thoracic cavity.It is the pressure in the space betweenparietal and visceral pleurae.Intrapleural pressure will be negative throughout respiration.Subglottal pressure (Ps ) Subglottal pressure is the pressure below the vocal folds. During normal respiration with open vocal folds the Subglottal pressure and Intraoral pressures are equal to alveolar pressure.
Intraoral or mouth pressure (Pm) is the pressure that could be measured within the mouth.Atmospheric (barometric) pressure: pressure exerted by weight of air in atmosphere on objects on earth’s surface. These pressure measurements are made relative to Atmospheric pressure.
Pressure Relationships• Intrapulmonary pressure and intrapleural pressure fluctuate with the phases of breathing• Intrapulmonary pressure always eventually equalizes itself with atmospheric pressure• Intrapleural pressure is always less than intrapulmonary pressure and atmospheric pressure
Respiratory Cycle• Respiration works by changing the volume of the chest cavity• Before the start of inspiration, respiratory muscles are relaxed, intra-alveolar pressure = atmospheric pressure, and no air is flowing.• At onset of inspiration, inspiratory muscles (primarily the diaphragm) contract, which results in enlargement of the thoracic cavity.• As the thoracic cavity enlarges, the lungs are forced to expand to fill the larger cavity.• Because the intra-alveolar pressure is less than atmospheric pressure, air follows its pressure gradient and flows into the lungs until no further gradient exists
Cont…• Therefore, lung expansion is not caused by movement of air into the lungs• Deeper inspirations are accomplished by contracting inspiratory muscles more forcefully, and by using accessory inspiratory muscles to enlarge the chest cavity further.• At the end of inspiration, the inspiratory muscles relax, the chest cavity returns to original size, and the lungs return to original size.• Although at rest expiration is a passive process, during exercise it is an active process and expiratory muscles (primarily abdominal muscles) contract to decrease the size of the chest cavity during expiration.
Breathing for speech Speech requires much more muscular control than quiet breathing, to sustain the correct pressure over the long vocalisations that humans typically produce. Without adequate breath control, the air goes out too fast.Therefore:• At the start of an utterance, the flow of air out of the lungs is braked by using the inspiratory muscles (external intercostals and/or diaphragm) to keep lung volume high• Once the resting expiratory volume has been reached, the expiratory muscles (internal intercostals) are used to push more air out until the end of the utterance.
Pressures of speechThe respiratory system operates at 2 levels of pressure.• The first level is the relatively constant supply of subglottal pressure required to drive the vocal folds. To produce sustained voicing of a given intensity, this pressure is relatively constant. The minimum driving pressure to make the vocal folds move would elevate a column of water between 3-5 cm H2O, with conversational speech requiring between 7 and 10 cm H2O. Loud speech requires a concomitant increase in pressure.• The second level of pressure is one requiring micro-control. Eventhough a constant pressure is required for phonation, the pressure can be rapidly changed for linguistic purposes such as syllable stress. Quick bursts of pressure can create rapid increases in vocal intensity and vocal pitch.
Speech production requires to maintain a constant pressurefor speech. During normal respiration, inhalation takes upapproximately 40% of the cycle, while expiration takes upabout 60%. The respiratory cycle for speech is markedlydifferent. During speech, only 10% of the respiratory cycle isspend on inspiration and about 90% for expiration. Speechrequires much more muscular control than quiet breathing.
Therefore : At the start of an utterance, the flow of air out of the lungs is braked by using the inspiratory muscles (external intercostals and/or diaphragm) to keep lung volume high . Once the resting expiratory volume has been reached, the expiratory muscles (internal intercostals) are used to push more air out until the end of the utterance.
• During speech production the respiratory cycle is altered to capitalize on expiration time and restrain the expiration through checking action i.e., the flow of air out of the inflated lungs is impeded or checked by the muscles of inspiration.• Checking action is extremely important for respiratory control of speech ,because it directly addresses a person’s ability to restrain the flow of air. Checking action permits to maintain the constant flow of air through the vocal tract and thus accurately controls the pressure beneath the vocal folds that have been closed for phonation. This is very important for maintaining constant vocal intensity and frequency of vibration.
• Pressure is also generated through contraction of the muscles of expiration when the lung volume is less than resting lung volume. These manipulations help to maintain a respiratory rate to match the metabolic needs, and even use the accessory muscles of inspiration and expiration to generate small bursts of pressure for syllabic stress.
Lung volumes required for speech• Hoshiko (1946) found that approximately 50% of vital capacity is inhaled for speech purposes.• Hixon et al (1973) have reported that ‘there are roughly defined lung volume limits within which certain types of utterances typically occur.• They state that in the upright posture most conversational speech of normal loudness is produced within the midrange through volumes encompassing approximately 35 to 60% of the vital capacity.• They also maintain that deeper breaths are taken during conversational speech than during normal quiet tidal breathing. During loud speech ,which demands higher subglottal pressures, speech is initiated from higher lung volumes (60 to 80 % vital capacity).
5- Methods of respiratory analysis:1- Invasive method:• Pneumography• Spirometroy• Oral manoetory• Electomyography• Fluroscopy• Cineoflurograph• Recording of pressure during breathing