Anatomy of the Phonatory System

Respiration

-power source

—physics makes our lungs expand and contract

—can’t compensate with muscles alone

-generates air flow and air pressure

—more pressure/airflow - rehabilitated with the least amount of effort

—airflow - positive pressure unless using negative to suction bolus down into esophagus

Airways

-Vocal folds divide the upper and lower respiratory tract

— larynx is demarcation

Upper Respiratory Tract

nose, mouth, pharynx, larynx

sinus infection, laryngitis, pharyngitis, tonsillitis, sinusitis

Lower respiratory tract

-trachea, bronchi, lungs, bronchioles, alveolar ducts, alveolar sacs

—pneumonia, bronchitis, trachea

Lungs

-rest on surface of diaphragm / bilateral / doesn’t have muscles and don’t move on their own

-encased in pulmonary pleural membranes

-pleural linkage

Plural Linkage

-resting position of lungs (without thorax) = collapsed

-resting position of ribs (without lungs) = expanded

-combination of forces = lungs slight expansion/ribs slightly compressed

Muscles of Inspiration

• quiet respiration

  • diaphragm

  • external intercostals

• forced inspiration/inhalation

  • costal elevators

    • sternocleidomastoid

Diaphragm

• unpaired muscle

• bilateral neural innervation (nerves come from left and right)

• at rest = domed position

• contracted = flattened position

External Intercostal Muscles

• 11 pairs of muscles

• run between ribs

  • downward and medial direction

• contraction

  • raise and expand ribcage

Sternocleidomastoid

• paired muscle on lateral neck

  • origin = sternum and clavicle

  • insert = mastoid process of temporal bone

• functions

  • turns the head

  • if head in fixed position

    • assists lift of sternum and upper ribs

      • can’t have a big breath and turn head to block off weak side at the same time (have to decide which one is more important)

Expiration/Exhalation

• no muscle contraction required for

  • passive exhale

• muscular action required when

  • forced exhalation

  • expiration goes below resting level

  • expiratory flow is controlled as during speech

  • always talk on exhale

Checking action

• muscular force used to resist thoracic recoil during the exhale

  • activates muscles of inhalation - resist so exhale comes out very slowly

• controls how much power source and how long potential speech could be

  • can support phrases with same amount of breath support for each syllable

Internal Intercostal Muscles

• 11 muscle pairs

  • lie deep to the external intercostals

• origin: lower border of ribs

• insert: inner face of rib immediately below

• function: compress ribcage during exhale

Breath Cycle - Rest

• expansion of thoracic cavity

  • diaphragm lowers (1.5 cm)

    • involuntary (automated and reflexive)

  • intercostals elevate ribs

• lungs follow thoracic wall

• air flows in until equal to atmospheric pressure

• once lungs are expanded, air can travel into lungs

Indicators of not using checking action

• loudness

• glottal fry (lack of breath support especially at the end pf a phrase)

Breath Cycle - Recoil

• abdominal pressure forces diaphragm back into dome position

• ribs release with torque force

• elasticity of lungs expels air until pulmonary pressure equal to atmospheric pressure

Resonance Vocal Tract cavities

• nasal, oral, pharyngeal

  • shape the acoustic signal created by VF vibration

  • modulate the airflow generated by respiratory system

    • articulation and resonance

Nasal Cavity

• velopharyngeal control of perceived nasality

  • VP Open =

    • airflow in nasal cavity

    • nasal resonance

  • VP Closed =

    • no airflow in nasal cavity

    • oral resonance

KEY CONCEPT What position is your palate in when breathing, swallowing, speech nasal and non-nasal sounds?

• breathing: port is open and soft palate is down and at rest

• nasal resonance: port is open and soft palate is down so sound resonates through nose

• swallowing: will close and lift - soft palate is up to prevent nasal regurgitation

• non-nasal sounds: palate lifted so sound goes out mouth not nose

Hyper vs hyponasality

• hypernasality: excess nasality

  • sound into the nose when you don’t want it there

• hyponasality: not enough nasality

  • blocking nasal cavity and air can’t come out and resonate

Oral Cavity

• articulation

• phoneme placement/manner

  • pressure points for positive and negative pressure

Pharyngeal Cavity

• velum to cricopharyngeus

• three primary circular muscles

  • superior (weaker because it comes back through pharynx)

  • medial

  • inferior pharyngeal constrictors (directs bolus in tight tube to go right to esophagus - swallowing) -strongest

• pharyngeal cavities

  • nasopharynx

  • oropharynx

  • hypopharynx (laryngopharynx) (below base of tongue)

Laryngeal Functions

• thoracic fixation (to create power in your chest when you close and hold vocal folds to change pressure)

  • change in intra-abdominal pressure

    • birthing

    • lifting

    • defecation

• sound production

  • speaking

  • singing

• airway protection

  • closes laryngeal passageway to lungs

  • cough reflex (to not aspirate)

Laryngeal Anatomy

• skeletal framework

• muscles: intrinsic/extrinsic

• microstructure of the vocal folds

Skeletal Framework

• hyoid bone and cartilages

  • fairly symmetrical

  • connected by membranes, ligaments, joints

• purpose

  • provides laryngeal framework

  • protects soft tissue

    • provides leverage for muscles during laryngeal position changes

Hyoid Bone

• u-shaped

• vertical level varies with age

  • 3rd cervical vertebra in adults

• no articulation with other bone

  • only free floating bone in body

• ‘tongue bone’

• greater and lesser horns

  • attach to middle pharyngeal constrictor

Laryngeal Suspension

• larynx suspended from hyoid

• suspended by muscles, ligaments, and membranes

  • stylohyoid m.

    • suspends hyoid from temporal bone

  • lateral and medial thyrohyoid

    • (membrane and muscle)

    • connects hyoid/thyroid

    • lifts and suspends thyroid

3 types of cartilage

• hyaline: respiratory

  • cricoid, thyroid, arytenoid

• elastic: doesn’t ossify

  • cuneiform, epiglottis, corniculates

• fibrous: attach tendons

• classification based on appearance and properties

Calcification of cartilages begins at…

• about 25 years of age

  • elastic cartilage doesn’t calcify

    • cuneiform, epiglottis, corniculates

Laryngeal Malacia

• congenital disease

  • soft cartilages (flap into and block airway)

    • can’t maintain framework

    • laryngeal opening constricted (arytenoids get sucked into airways)

  • laryngeal stridor (noisy breathing)

  • often requires tracheotomy

Laryngeal Cartilages

• thyroid

• cricoid

• arytenoids

• corniculates

• cuneiforms

• epiglottis

Thyroid cartilage

• largest

• paired plates (thyroid lamina)

• most anatomically variable

  • almost right angle males (adam’s apple)

  • rounded females

• notch

  • gender differences

  • shaved in transsexuals

Thyroid cartilage cont.

• inner surface attachments

  • true vocal folds

  • ventricular bands (false folds)

• cricothyroid

• thyroepiglottic ligament

Cricoid cartilage

• only complete ring

  • signet shape

• sits on top of trachea below thyroid

• posterior surface of lamina

  • broad and oval

Arytenoids

• paired (function like pinball levers)

• pyramidal shape

• processes

  • vocal

    • attaches vocal ligament of TA

  • muscular

    • attaches TA, LCA, PCA