Speech midterm

Breathing vs. respiration

• Breathing: inhaling (inspiration) and exhaliation (expiration)

• Respiration: exchenge of oxygen and carbon dioxide at the cellular level

Speech breathing

• The adjustment of normal breathing for speech production

• Speech requires a controlled, steady stream of outgoing air

• 10% inhalation

• 90% exhalation

Boyle’s law

There’s an inverse relationship between volume and pressure

During inhalation (passive)

1. Diaphragm contracts and flattens

2. Thoracic cavity increases in size

3. Lung volume increases

4. Pressure in lungs drops

5. Air rushes in

During exhalation (passive)

1. Diaphragm relaxes

2. Thoracic cavity decreases in size

3. Lung volume decreases

4. Pressure in lungs increases

5. Air flows out

Pulmonary system

AKA the respiratory system

• Upper respiratory: oral and nasal cavities, pharynx

• Lower respiratory: trachea, broncial tree, lungs

Chest wall system

• Rib cage

• Sternum

• Thoracic vertebrae

• Abdomen

• Diaphragm

Trachea

• The major passage for air between larynx and lungs

• Open tube with ~20 horseshoe shaped cartilages

• Fibrous membrane and smooth muscle between cartilage rings holds the structure together

• Goblet cells produce mucus to trap particles inside the trachea, and cilia sweep mucus up the trachea to remove them 

Bronchial tree & alveoli

• Primary (left and right) bronchi serve as airways to the lungs

• Secondary bronchi subdivide from the primary bronchi to serve the individual lobes of the lungs

• Tertiary bronchi serve the individual segments of each lobe of each lung

• Terminal respiratory bronchioles supply air to the alveoli for gas exchange

• Ends in alveoli that allow for gas exchange with capilaries due to a large, thin, and permeable surface

• Kept constantly inflated by surfactant

Lungs

• The right lung is larger

  • It’s shorter but wider, losing some space to the liver

  • 3 lobes: superior, middle, and inferior

• The left lung is smaller 

  • Shares the left side of the thorax with the mediastinum (heart cavity)

  • 2 lobes: superior and inferior

Primary inhalation muscles

• Diaphragm: contracts and moves downwards

• External intercostals: pulls ribs up and out

Primary exhalation muscles

• Abdomen: compresses thoracic cavity

• Internal intercostals: pulls ribs down

Pleural linkage

• Maintains expansion of the lungs and ribcage

• The inner/visceral pleural membrane encases the lungs

• The outer/parietal pleural membrane lines the inside of the chest wall

• The interpleural space in between is filled with a liquid surfactant that causes negative interpleural pressure, sucking them towards each other

Rib movement

• The ribcage is somewhat elastic

• Upper ribs move antero-posteriorly (pump)

• Lower ribs move transversely (bucket)

Tidal breathing

• Normal, quiet breathing while at rest

• Inspiration is active

• Expiration is mostly passive due to elastic recoil forces

• 40% inhalation

• 60% expiration

Lung volumes

• Tidal: the volume of air we breath in and out during a normal cycle

• Inspiratory reserve: the volume of air we can inhale above tidal

• Expiratory reserve: the volume of air we can voluntarily exale below tidal

• Residual: volume of air that can’t be exhaled voluntarily from the lungs

Lung capacities

• Vital: the maximum amount of air a personal can inhale or exhale voluntarily

• Functional residual: the amount of air remaining after taking a breath

• Inspiratory: the amount of air that can be inhaled

• Total lung: all the air the lungs can possible hold

Relaxation pressure

• Created by elastic recoil trying to return the lungs and chest wall to resting position (equilibrium)

• Active forces: muscles contractions

• Passive forces: gravity, elastic recoil, surface tension of alveoli

• Lung volume dictates the level of relaxation pressure

Resting lung volume

• Outward chest expansion = inward lung recoil

• Exists after we take a full breath

Above resting lung volume

• Positive relaxation pressure

• Elastic recoil wants lungs smaller, and eventually the ribs as well

• Exhalation can be achived with passive pressure alone

• Pressures above 60% VC are too much to sustain phonation

• At pressures between 60% and RLV, active muscle contraction and passive pressure are used to sustain phonation

Below resting lung volume

• Negative relaxation pressure

• Outward chest expansion overpowers lung recoil

• Exhalation can only be achieved using active muscle contraction

• At pressures below RLV, only active muscle contraction is used to sustain phonation

Breath group

Number of words or syllables spoken on one exhale

Speech breathing - body type

• Endomorphs (fat) use greater abdominal wall activity than rib cage activity compared to endomorphs (skinny)

• Additional mass on the abdomen exerts a pulling force that tugs on the diaphragm, inhibiting rapid contraction

Speech breathing - cognitive linguistic factors

• Inspiration mainly occurs during grammatical and semantic boundaries

• The longer the phrase, the deeper the inhalation

• When you’re actively thinking, you generally have shorter breath groups

Speech breathing - respiratory demands

• Speech breathing = slight hypovention and irregular breathing

• Exercise/being active = larger breaths, shorter breath groups

Hypervention

• Excess of CO2

• Dizziness, blurred vision

Hypovention

• Lack of oxygen

• Impared cell respiration, tissue damage, death

Clavicular breathing

• Shoulder lifting

• Uses neck muscles heavily

• Less activation of diaphragm

• More vertical than horizontal expansion

• Least efficient

Chest breathing

• Rib cage expanding a lot during inhalation

• Expansion is primarily in the chest rather than the diaphragm

• Less efficient

Diaphragmatic breathing

• Abdomen moves outwards

• Diaphragm moves freely

• Most efficient pattern

Neural control of breathing

• Respiratory center located in the medulla oblongata

• Muscles controlled by the phrenic and intercostal nerves

Sensory receptors

• Chemoreceptors monitor CO2, pH, O2, and more

• Mechanoreceptors monitor tissue movement and stretch

Airflow

• The volume of air moving through a given area of tube per unit of time

• Airflow increases when driving pressure increases (more push, more flow)

• Airflow = driving pressure/resistance

Airway resistance

• Narrower airways = more resistance

• Doubling airway diameter decreases resistance by a factor of 16

• About half of airway resistance is in the upper airway

• Lower airway resistance is mainly due to the trachea and bronchi

• Rapid shallow breathing = most of work is done against airway resistance

Elastic resistance

• Work required to prevent tissue from springing back once expanded

• Deep slow breathing = most of work is done against elastic resistance

Viscosity

• Internal friction within air/fluid

• High viscosity = high friction

• Higher viscosity increases breathing effort

Airflow types

• Laminar: smooth, efficient, directly proportional to driving pressure

• Turbulent: chaotic, eddies/whirpools, requires more driving pressure, common in trachea and large airways

Phonation

• The production of speech sounds through vibration of the vocal folds

• The vocal folds repeatedly open and close, creating puffs of air that generate sound waves

Larynx

• Located in the front of the neck anterior to the esophogus and above the trachea

• Protects the airway during swallowing

• Phonation

• Airflow control during breathing

• Autonomic coughing

• Throat clearing

• Valsalva manuver: stabilization during heavy lifting (vocal folds are adducted to seal the airway, making the thoracic cavity become ridged which allows the lower body to more efficiently generate movement)

  
  

Laryngeal cartilages

• Unpaired

  • Thyroid

  • Cricoid

  • Epiglottis

• Paired

  • Arytenoids

  • Corniculates

  • Cuneiforms

Cricothyroid joint

• Allows larynx to rock/tilt

• Lengthens vocal folds

• Helps control pitch

Cricoarytenoid joint

• Opens and closes vocal folds

• Rocks and slides (undulating motion)

Aryepiglotic folds

• Connects top of epiglottis to arytenoids

• Just the edges

• Pull the epiglottis backwards to close the larynx during swallowing

False vocal folds (ventricular folds)

• Mainly protective, not sound producers

• Capable of limited movement like closing during swallowing and forceful activity

True vocal folds

Complex valves that vibrate and open and close

Vibrating element of larynx

Multilayerd structure

Glottal space

• Glottis: Space between the true vocal folds

• Supraglottis: area above the vocal folds

• Subglottis: area below the vocal folds

Intrinsic muscles of larynx

Throat muscles located entirely within the larynx

• Fince control of phonation

• Open and closes vocal folds

• Adjusts tension (pitch)

• Posterior cricoarytenoid

• Lateral cricoarytenoid

• Interarytenoid

• Cricothyroid

• Thyroarytenoid

Posterior cricoarytenoid

ONLY vocal fold abductor

Lateral cricoarytenoid

Adducts vocal folds

Interarytenoid

• Adducts vocal folds

Cricothyroid

Lengthens vocal folds (raises pitch)

Thyroarytenoid

Main body of the vocal folds

Extrinsic muscles of larynx

• Attaches larynx to structures outside of it

• Moves entire larynx

• Stablizes position

• Thryohyoid

• Sternothyroid

• Omohyoid

• Sternohyoid

Intrinisc membranes and ligaments

• Connect laryngeal cartilages to each other

• Conus elasticus membrane

• Quadrangular membrane

Conus elasticus membrane

• Below the vocal folds

• Medial cricothyroid ligament and lateral cricothyroid ligament

• Upper portion thickens to form the vocal ligament, the core of the true vocal fold

Quadrangular membrane

• Above the vocal folds

• Superior free margin forms the aryepiglotic folds

• Inferiror free margin forms the vestibular ligament and false vocal folds

Extrinsic membranes

Attaches the larynx to the hyoid bone above and the trachea below

• Thyrohyoid membrane: connects thyroid cartilage ↔ hyoid bone

• Cricothyroid membrane: connects cricoid ↔ thyroid cartilage

• Cricotracheal membrane: connects cricoid ↔ trachea

Extrinsic ligaments

Attaches the larynx to the hyoid bone above and the trachea below

• Thyroepiglottic ligament: connects thyroid cartilage ↔ epiglottis

• Hyoepiglottic ligament: connects hyoid bone ↔ epiglottis

• Cricotracheal ligament: connects cricoid ↔ trachea

Vocal fold histology

• Covered in a mucus blanket secreted from glands within the vestibular folds (false vocal folds)

• Epidermal layer

• Basement membrane

• Lamina propia:

  • Superficial (gelatin)

  • Middle (elastic)

  • Deep (collagen)

• Thyroarytenoid muscle

Laryngeal innervation

Vagus nerve

Reccurent branch

• Motor control to all intrinsic muscles (except cricothyroid)

Superior branch

• Internal: sensory

• External: cricothyroid control