Respiratory System

Respiratory System

Eric Dane:

- few words per breath

- low volume

Endoscopic view of larynx:

- liquid wasn’t swallowed properly (liquid down windpipe)

- lack of coordination in breathing and swallowing

Respiratory System Functions (5)

• ventilation (physical movement of air) and gas exchange

• filtering, warming, and humidifying air

• sound production

• airway protection

• sense of smell

*during a swallowing process, breathing pauses to protect airway

Organization of Respiratory System

upper resp. tract

• nasal cavity

• oral cavity

• pharynx

• larynx (divides upper and lower tracts)

Lower resp. tract

• trachea

• bronchi

• lungs

Lower Tract - “Breathing Pump”

• Pulmonary apparatus

  • lower airways

  • lungs

• Chest Wall

  • rib cage

  • diaphragm

  • abdominal wall

  • abdominal content

Pulmonary apparatus - Lower airways:

• Trachea - made of ‘c’ shaped cartilage

  •  inferior to larynx

  • trachea extends into the bronchial tubes

  • within the lungs, the bronchi tubes extend into lobar bronchi tubes (goes for 20 generational branches)

• The Bronchi - are made of cartilage as well

  • smaller divisions of bronchi which are called “bronchioles”

• Bronchioles -

  • lack the cartilage of trachea and bronchi so they are less rigid

  • instead, bronchioles are made up of smooth muscle

  • bronchioles eventually lead to alveoli

Pulmonary apparatus - Lungs

• Lungs - are porous and spongy

  • contain many elastic fibers (so that the alveoli can stretch during inhalation and exhalation)

• 5 lobes of the lungs - 3 on the right side, 2 on the left ( to accomadate the heart)

  • lungs are covered by the visceral pleura (hard membrane - outer most wall of the lungs)

  • also covered by the parietal membrane (inner most wall of the lungs, touches the lungs - much thinner membrane)

• Pleura and Pleura fluid

  • essential for respiration

  • pleura fluid reduces friction as the pleura moves past one another

  • pleura are also critical for pleura linkage, allowing the entire chest cavity to move as one unit

• Alveoli - tiny air sacs at the very end of bronchioles where gas exchange takes place (about 300 million)

  • also made of elastic fibers to expand and contract

  • inside alveoli is filled with lipids and proteins (known collectively as surfactant)

  • surfactant lower the surface tension for easier breathing

  • alveoli wrapped in mesh casing of pulmonary capillaries (blood vessels)

  • gas moves into the blood via pulmonary capillaries

• Internal and External Respiration

  • Internal respiration - the exchange of oxygen and carbon dioxide between tissue capillaries and tissue cells (THINK - air exchange between BLOOD AND TISSUE)

  • External respiration - exchange of oxygen and carbon dioxide int he alveoli and blood of pulmonary capillaries (on the pulmonary capillary level) (THINK - air exchange between LUNGS AND BLOOD)

*lower airways and lungs make up the pulmonary apparatus of the lower respiratory tract

Lower Tract - Chest Walls

• Rib Cage - the skeletal portion of chest wall

  • protects lungs and heart

  • part of the thoracic vertebrae

  • 12 pairs of ribs: first 7 pairs are “true” ribs because they are attached to the sternum AND spine - bottom 3 pairs are “false” ribs because they only attach to the spine and indirectly to the top 7, bottom 2 pairs are known as “floating” ribs because they are only attached at the spine

• Sternum - protects middle of the chest

  • positioned above the heart

  • made of 3 parts: the manubrium (the first 2 ribs), the blade (rib pairs 3-7), and the typhoid process (bottom pairs)

• Diaphragm - a muscle, between thorax and abdomen

  • left side sides lower than right side to accommodate the heart

• Abdominal wall - oblong shape with 15 vertebrae (lumbar and sacral region)

  • include muscle and connective tissue

  • contains and protects organs, maintains anatomical position

• Abdominal content - stomach, intestine, etc.

  • involved in digestion

  • suspended by “suction force'“ (breathing muscles pull upward creating low pressure to hold abdomen content up)

Pulmonary apparatus and Chest Wall as a unit

*plural linkage allows pulmonary apparatus and chest wall to operate as a unit

• allows for effortless breathing

• compare the plural linkage to two people leaning in opposite directions while holding hands - like a tug-of-war

  • the lungs are pulled in by the chest wall and stretched out - while the chest wall compresses

• Filter in Respiratory System - mucus filters dust out, cilia moves in wave-like pattern to activate filtration

• Humidification - to prevent hoarse speech

  • humid, warm air allows for smooth movement of vocal folds

Inspiratory and Expiratory muscles

Inspiratory muscles - muscles that expand the rib cage during inspiration so air can flow into lungs

Expiratory muscles - muscles that compress the rib cage and abdomen to expel air out of lungs

Inspiratory muscles

• diaphragm

• rib cage wall

  • external intercostals

  • sternocleidomastoid

  • scalene (anterior, medial, and posterior)

Diaphragm

• divided into 3 sections

1) Sternal

• origin in the lower and back border of xiphoid process (tip of sternum)

• course is superior and medial

• intersection is the central tendon

• *the central tendon contracts and moves diaphragm down/flatten

2) Costal (bottom of ribs)

• origin in the low border and inferior surface of ribs 7-12

• course is superior and medial

• instertion at central tendon

3) Vertebral

• origin at upper lumbar vertebrae

• course is superior and medial

• insertion at central tendon

- 3 important openings to diaphragm

1) aortic hiatus - opening for aorta

2) esophageal hiatus - where digestive tract passes

3) Foramen vena cava - where largest vein passes

*all 3 allow for major vessels, nerves, and esophageal tube to pass through muscular wall w/o keeping diaphragm from breathing

- the diaphragm is primary muscle for inhalation

- during contraction, central tendon pulls down and forward and the lower 6 ribs elevate to allow lung expansion

Rib Cage Wall

- External intercostals

• 11 connected muscles that fill the outer portions of the rib interspaces

• each muscles connects from bottom border of upper rib all the way to top border of inferior rib

• these muscles pull the ribs up and out to make room for air

- Sternocleidmastoid

• origin at sternum and clavicle

• insertion on skill behind the war

• this muscle pulls up the sternum, clavicle, and ribs

- Scalene

• elevate top 2 ribs from inspiration

Anterior -

• origin at C3-C6

• insertion at inner border of top of 1st ribs

• elevates 1st rib

Medius -

• origin at C2-C7

• insertion at 1st rib

• also elevates 1st rib

Posterior

• origin at C5-C7

• insertion at outer surface of 2nd rib

• elevates 2nd rib

Accessory inspiratory muscles (general functions only)

- Pectoralis major

- Pectoralis minor

- Subclavicus

- Serratus anterior

- Serratus posterior superior

- Lateral iliocostalis cervicis

- Lateral iliocostalis thacis

- Levatores costarum

• all of these accessory muscles serve to elevate and support ribs and sternum during INSPIRATION

• they all function to assist in breathing

• protect organs

• maintain thoracic stability

Expiratory muscles

• rib cage wall

  • internal intercostals

• abdominal wall

  • rectus adbominis

  • external oblique

  • internal oblique

  • transversus abdominis

Rib Cage Wall

- Internal intercostals

• 11 muscles that fill the spaces between each rib on the INSIDE

• origin at inferior border of every top rib

• insertion at superior border of every bottom rib

• depresses ribs and stiffens interspaces

Abdominal Wall

- Rectus Abdominis

• origin at the “abs” - what you would see as abs in a picture

• insertion at outer surfaces of the 5th-7th costal cartilages and lower sternum

• depresses lower ribs and sternum

• 
  

- External Oblique

• origin at upper surface of coccxal bone and abdominal apornuerosis

• insertion at lower 8 ribs

• depresses lower 8 rubs and forces the front and sides of abdominal wall inward

- internal oblique

• origin into abdominal aponeurosis and lower borders of costal cartilages of lower 4 ribs

• insertion at face of coxal bones and lumbodorsal fascia

• depresses lower ribs and forces front and sides of abdominal wall inward

- Transversus Abdominis

• origin covers inner surfaces of costal cartilages of 7-12 (deepest ab. muscle)

• insertion at abdominal aponeurosis

• forces front and sides of abdominal wall inward

Accessory expiratory muscles

• general function of accessory expiratory muscles is to depress the ribs during expiration

• abdominal wall serves to

  • flexors of vertebral column

  • enclose and support abdominal contents

  • assist in respiration

  • urination, defecation, emesis, and giving birth

Movement of rib cage

• during inspiration the rib cage moves up and outward

• during expiration the rib cage moves down and inward

  • bucket handle analogy

• Lungs expand and diaphragm flattens

Movement of abdominal wall

• during inhalation the abdominal wall moves outward

- the different movements of the rib cage, diaphragm, and abdominal wall impact different variables of respiratory control like

• lung volume

• pressure

• chest wall shape

Lung Volume

• size of 3-D object of respiratory system

• volume changes as we breathe

• volume is represented by a waveform = known as Respiratory spirometer

• better defined as a single specific amount of air int he lungs at some point during breathing (auantity of air)

Features of Lung Volumes

• Tidal Volume

• Inspiratory Reserve VOlume

• Expiratory Reserve VOlume

• Residual Volume

- Tidal Volume

• volume of air inspired or expired during breathing cycle

- Inspiratory Reserve Volume

• maximum breath that can be inspired (beyond TV)

- Expiratory Reserve Volume

• maximum volume of air that can be expired (after normal expiration)(i.e. continous coughs)

- Residual Volume

• air left after ERV (so lungs don’t collapse)

Lung Capacity

- Vital Capacity (VC)

• maximum volume of air that can be expired after a maximum inspiration

- Inspiratory Capacity

• maximum volume of air that can be inspired from the end - expiratory level (its the TV + IRV)

- Functional Residual Capacity

• air left at the resting tidal end - expiratory level (residual volume and ERV)

- Total lung Capacity

• sum of all volumes

Pulmonary Ventilation

• amount of air inspired or expired

• Minute Ventilation - TV x breathing frequency

• Apenic period - no air flouring into or out

Pressure

• the force distributed over a surface of a close space

• pressure can be changed by changing the volume of a gas in a closed space

  • volume influences pressure

• Boyle’s Law - inverse relationship between pressure and volume (only talks about gas in a closed space)

- Atmospheric Pressure

• presses on all things it touches, in turn, creates slight baseline force

• expressed in Toor or mmHg

• varies with elevation, temperature, and humidity

• pulmonary ventilation depends on periodic changes in lung relative to atmospheric pressure

  • during inspiration pressure in your body is lower than outside pressure = this forces air into your lungs for inhalation

  • during expiration, pressure in your body is higher than outside air which forces air out of your lungs

• air wants to move away from high pressure to low pressure

Muscular forces on Pressure

• Alveolar pressure - sum of all passive and active forces that operate in respiratory system

  • as lung volume decreases, alveolar pressure increases (Boyle’s Law)

• Relaxation pressure = when lungs are relaxed (comes from elastic recoil of chest wall)

• when the lungs are stretched beyond normal limits, the elastic fibers in the lungs will recoil inward creating positive pressure, pushing air out, causing expiration

• vice versa - small volume, recoils pull outward, creating negative pressure, causing inspiration

Aggregate Pressure determining inspiration

• inspiration begins by expanding thoracic cage

  • enlarges intrapleural space, lowers intrapleural pressure

• pulls alveoli open, lowers alveolar pressure

• air flows down the pressure gradient from atmosphere into lungs

All Pressures Determining Expiration

• diaphragm relaxes and lungs recoil

• volume goes down, pressure goes up above atmospheric pressure

• leads to expiration

Lung compliance

- the main influence on lung volume and lung pressure

• lung compliance is the ease by which lungs can inflate

• elasticity vs. stiffness

• can impact pressure and volume, therefore, airflow

  • Excessive compliance - elasticity of lungs is above normal, the recoil of the lungs decreases resulting in manual muscular effort to push air out of lungs for adequate speech (causes decreased pressure)

  • Lack of compliance - lungs are stiff and thick, they resist inflation (causes an increase in pressure)

 Respiratory control variables

- pressure

- volume

- chest wall shape

Chest Wall Shape

• ribcage and abdominal wall collectively

• during inspiration and expiration

  • the abdominal wall moves in and out horizontally

  • the ribcage moves in and out vertically

• vigorous activity engages the ribcage more than the abdominal wall

*these variable differ (pressure, volume, and chest wall shape) depending on the lung activity (breathing vs. speaking) (tidal breathing vs. speech breathing)

Differences in tidal breathing and speech breathing

- different purposes

- different nervous system controls

- different variables of respiratory control

Purpose

Tidal breathing

- ventilation

- gas exchange

Speech Breathing

- airflow for speech production

Nervous system

Tidal breathing

- controlled by brainstem (because its involuntary)

Speech Breathing

- controlled by higher brain systems

the higher systems will override the brainstem breathing

Cranial nerves that dilate the upper respiratory tract (the laryngx)

- IX

- X

- XII

Cranial nerves that elevate the rib cage

- XI

Spinal nerve that elevates

- The rib cage wall: C1-L2

- Diaphragm: C3-C5

- Abdominal wall: T1-L2

Variable Outputs - Lung Volume

Tidal breathing

- stays in range of resting expiratory and end-inspiratory levels

- TV is 10-20% of VC

- lower ventilation

Speech breathing

- midrange of possible lung volumes

- higher ventilation (depends on speech task)

- lung volume varies with speech

Variable Outputs - Alveolar Pressure

idal breathing

- ranges from -1.0 (inspiration to +1,0 (expiration)

• relaxation pressure

Speech breathing

- ranges from 8-10 cm HzO

• increases as loudness increases

Extended Steady utterance

*the main idea is that at high lung volumes, inspiratory muscles act as a brake system. At low lung volumes, expiratory muscles act as a booster

- A steady utterance like “aaaaaaaaaaa”

• at the beginning of the utterance the lung volume is high and alveolar pressure has a quick increases and then plateaus for the duration of the utterance

• at the end of the utterance the lung volume steadily decreases and alveolar pressure had a quick drop off

In-Class activity to depict extended steady utterance activity:

• airflow decreases as the utterance is spoken

• airflow = output, would be more during speaking utterances

• Boyle’s law does not apply here because our lungs have a way to get air out (whereas Boyle’s law only applies to enclosed spaces with trapped air)

• pressure decreased BEFORE the utterance, and increases during utterance and stays constant because muscles are not constricting MORE than they already are to get more sounds out

• during speech, inhalation is very quick and exhalation is more steady

• speech breathing is in the midrange of tidal volume

Connected Speech

• during utterances, lung volumes rise quickly and lower more slowly

• during inspiration, alveolar pressure is negative. Positive during expiration

• both aforementioned changes in volume and pressure remain relatively constant

• expiratory muscles are needed to put out utterance

  • mostly abdominal muscles

Variable Outputs - chest wall shape

Tidal breathing

- relaxed

Speech breathing

- rib cage moves outward

- abdominal wall goes inward

*Body position - also effects speech because it effects lung capacity depending on how you are sitting or standing (whether gravity is working for you or against you)

Body Type and Speech breathing

Endomorph - stocky build with more fat in the middle of the body

• abdominal wall is more inward

Mesomorph - muscular build

• varies between endo and meso

Ectomorph - thin, lanky build

• ideal for speech because of slow muscle fibers

Age and speech breathing

• changes iin anatomy and physiology during development

• much variability in infants and toddlers

• mechanical speech-breathing develop by age 10 (adult like speech breathing)

• mostly unchanged in adults (until senescence)

  • senescent adults tend to

    • have larger lung volume breath groups

    • use more VC

    • expend more air per syllable

*no clear differences in breathing between genders, other than difference in lung volume size

High drive conditions and speech breathing

• under high-drive conditions speech breathing is

  • higher ventilation

  • fewer syllables per breath

  • higher average airflow

  • no phonated expirations

  • larger lung volume, rib cage wall volume and abdominal wall excursions

Cognitive-linguistic demand for speech breathing

• inspiration at structural boundaries (like commas)

• inspirations are larger when breath groups are longer

• expirations with more speech end at smaller lung volumes

• high cognitive-linguistic loads are associated with more silent pauses (when you think hard about what to say, you take more pauses in speaking)

Social variables

• short and long term ventilation change during a normal conversation

• resting tidal inspirations are quicker when listening than in quiet

• breathing movements correlate during turns of a conversation

Laryngeal Anatomy

Larynx = the voicebox

Larynx Relevance to SLP

• a point where air makes contact to maintain successful breath

• it creates subglottic pressure to maintain lung volume (prevents lung collapse)

• Protects airway through coughs (expel and prevent foreign objects)

*biological functions of larynx

• generates sound (speech sound)

*non-biological functions of larynx

Example of laryngeal impairment:

- aspiration (below level of true vocal folds)

- nodules

- laryngeal paralysis (one side passes midline to accomodate)

Skeletal Framework

• Bone

  • Hyoid

• Cartilages (supporting connective tissue)

  • thyroid

  • cricoid

  • aryteniod

  • corniculate

  • cuneiform

  • epiglottis

Hyoid

*the body’s only floating bone

• made up of 3 parts

  • body (anterior)

  • cornu (“horns”)

    • greater born on the side of hyoid

    • lesser horns superior and anterior

*is point of attachment for tongue, floor of mouth, larynx, and pharynx

• all are muscles

Thyroid Cartilages

*largest laryngeal cartilage

• made up of…

  • thyroid lamina (large part - the “shield”)

  • angle of thyroid

  • superior notch

  • superior and inferior horns/cornu

Cricoid Cartilage

• shaped as signet ring

• made of…

  • arch

  • quadrate lamina (back)

  • articular facet (depression that connects the cricoid to the thyroid)

*only cartilage that completely encloses upper airway

Arytenoid Cartilage

• paired pyramids

• posterior of larynx, above cricoid

• made up of…

  • muscular process (in the back)

  • vocal process (close to folds)

  • vocal ligament

  • apex

*looks like a lollipop

• attachment point for laryngeal muscles

Corniculate Cartilage

*the “cap” of arytenoid

• no real importance

Cuneiform Cartilage

• support/stiffen vocal folds

Epiglottis

• leaf-like

• the top part of the structure is thick

• the bottom part of the structure is think

• it sits behind the hyoid

• upright at rest

• inverts during eating

Laryngeal Joint

• criothyroid

• crioarytenoid

*joints connect bone to bone

Cricothyroid

• attaches cricoid and thyroid

• facilitate rotating and gliding of laryngx

  • forward movement (*anterior, posterior movement)

Cricoarytenoid

• connects cricoid and arytenoid

• rocking and gliding

Internal laryngeal topography

• laryngeal cavity

• vocal folds

• ventricular folds

• laryngeal ventricles

• laryngeal membranes and ligaments

Laryngeal Cavity

• starts at the vestibule/aditus (above glottis)

• stops at cricoid cartilage

• made up of…

  • supraglottal

  • glottal

  • subglottal

• supraglottis

  • bound by ventricular folds

• glottal cavity

  • between and at the level of vocal folds

• Subglottal cavity

  • bound by the cricoid cartilage just below, and just above the vocal folds

Vocal Folds

• 5 layers of the vocal folds

  • epithelium (surface of the folds)

  • lamina propria (superficial, intermediately deep)

  • thyrovocalis muscle (inner most layer of the vocal folds)

• membrane layer = is 60% of the folds (more elastic to allow for the vibrations)

• cartilage layer = 40% of the folds

• can also be divided into 3 layers:

  • mucosa

  • ligament

  • muscle

• or 2 layers:

  • function

  • cover (vibration) and body (stiffness/structure)

- Epithelium

• stratified squamos layer (for protection of the vocal folds agaisnt abrasions)

- Lamina Propria

• different types of connective tissue

- Thyroid Vocalis

• the muscle

• stiffness changes

Ventricular Folds

• known as the “false” vocal folds

• has ventricular ligaments and a small few muscle fibers

• closes airway completely (true vocal folds leave a small opening) (it is a medial compression/adduction)

Laryngeal Ventricles

• a depression between the ventricular and true vocal folds

• the structure that SECRETES MUCUS (to lubricate the vocal folds for phonoation)

• the laryngeal ventricles sits above the vocal folds (this way, the mucus can drip down to true vocal folds)

*between the true and false vocal folds

Laryngeal membranes and ligaments

• intrinsic

• extrinsic

• membranes are NOT the primary facilitator of movement - that is the job of muscles

Intrinsic

*connects cartilages of laryngeal structures to each other

Membranes -

• conus elasticus

• quadrangular

• lateral cricothyroid

Ligaments -

• vocal

• centricular

• thyroepiglottic

• middle cricothyroid

Conus elasticus (membrane)-

- connects the cricoid, arytenoid, and thyroid cartilages

- connects to middle and lateral cricothyroid membranes and the vocal ligaments

Quadrangular (membrane) -

- connects the epiglottis, thyroid cartilage, arytenoid cartilage, and carniculate cartilage

- the quadrangular membrane is thick at its bottom because it becomes the ventricular ligament

Thyroid epiglottic (ligament) -

- runs from thyroid cartilage to epiglottis

Extrinsic

*connects laryngeal structures to OUTSIDE structures

Membranes -

• cricotracheal

• hypothyroid

Ligaments -

• hypoepiglottic

• middle hypothyroid

• lateral hypothyroid

Cricotracheal (membrane) -

- connects the cricoid cartilage to tracheal rings

Hypo epiglottic (ligament) -

- connects hyoid bones to epiglottis

Hypothyroid (membrane) -

- connects the hyoid bones to thyroid cartilage and eventually becomes the middle and lateral hyothyroid ligaments

Laryngeal forces influencing movement

• Passive

  • recoil of muscles, cartilages, and connective tissue

  • surface tension

  • gravity

• Active

  • contraction of intrinsic, extrinsic, and supplementary muscles

Laryngeal muscles

• intrinsic

• extrinsic

• supplementary muscles

Intrinsic - inside the laryngx (both the origin and insertion are in the laryngx

• 5 main muscles

  • thyroarytenoid

  • posterior cricoarytenoid

  • lateral cricoarytenoid

  • interarytenoid

  • cricoarytenoid

• Forces on the intrinsic laryngeal muscles

  • will produce medial compression/ adduction

  • longitudinal

Thyroarytenoid (TA)

• originates in inner surface of thyroid to arytenoid cartilage

• bulk of vocal folds

  • thyrovocalis

  • thyromuscularis

• functions to contract longitudinal fibers shorten the distance, the distance decreases between the thyroid and arytenoid (tension here increases)

• vertical fibers influence ventricular folds

*to remember the function of the thyroarytenoid, think of a collegiate TA - a TA and the thyroarytenoid HELP

Posterior cricoarytenoid (PCA) -

• originates on back of surface of cricoid, ends at arytenoids (back surfaces)

• contracts/abducts (because arytenoids rock outward)

Lateral cricoarytenoid (LCA) -

• cricoid to arytenoid

• side instead of the back (like the PCA)

• internally rocks arytenoid forward (medial compression/adduction)

Interarytenoids

• transverse

  • back of arytenoid to same location at other arytenoid

• oblique

  • from top of one arytenoid to bottom of opposite arytenoid

*arytenoids move closer by medial compression

Cricothyroid -

• originates from outer front and side lower

• during contraction pars rectus decreases/rocks

• during contraction pars obliques slides (cricoid and thyroid) (anterior and posterior way)

Extrinsic - laryngx to outside structures

• 3 main muscles

• role is to support and fixate (the framework for laryngeal muscles)

Sternothyroid -

• sternum to thyroid

• contracts to pull thyroid downward

Thyrohyoid

• from thyroid to hyoid

• decreases distance between thyroid and hyoid

Inferior constrictor

• from median seam to back of pharyngx

• muscles fan out and down to thyroid and hyoid

• contraction moves sidewall of pharynx inward

Supplementary

• divided into 2 groups of supplementary muscles

• Suprahyoid

  • digastric

  • stylohyoid

  • mylohyoid

  • geniohyoid

  • hyoglossus

  • genioglossus

• Their overall function is to pull HYOID UP

• Infrahyoid

  • sternohyoid

  • omohyoid

Digastric

• functions to contract and pull the hyoid bone up and forward OR up and backward

• has an anterior and posterior component

• the anterior digastric goes from inside the lower border of the mandible to the lesser cornu of the hyoid

• the posterior digastric goes from the mastoid process to the lesser cornu hyoid, too

Stylohyoid

• functions to contract and pull the hyoid bone up and back

• goes from the lateral and back surface of the styloid process to the body of the hyoid

Mylohyoid

• functions to contract and pull up and forward on the hyoid bones

• goes from the inner surface of the mandible to the tendinous midline raphe (or the front side of the hyoid)

Geniohyoid

• functions to contract and pull up and forward on the hyoid

• goes from the inner surface of the front of the mandible of the front surface of the body of the hyoid

Hyoglossus

• functions to contract and pull the tongue down and back AND the hyoid bone up

• goes from the inner surface of the mandible to the undersurface of the tongue and hyoid

Genioglossus

• functions to contract and pull the hyoid bone up and forward

• goes from the inner surface of the mandible to the undersurface of the tongue and hyoid

Infrahyoid supplementary laryngeal muscles

Sternohyoid

• functions to contract and pull down on the hyoid

• goes from the back surface of the sternum and inner clavicle to the lower edge of the hyoid

Omohyoid

• functions to pull down on the hyoid

• has an anterior and posterior component

• the anterior omohyoid goes from the intermediate tendon to lower edge of the greater cornu of the hyoid

• the posterior component goes from the edge of the scapula to the intermediate tendon

Unit 5: Velopharyngeal - Nasal

Part 1:

Relevance to speech and swallowing -

• air pressure management

• controls resonance

• prevents nasal regurgitation

• airway protection

Structures:

• skeletal framework

• velum

• pharyngx

• nasal cavities

• outer nose

Skeletal Framework -

• cranial bones

  • temporal bone (paired)

  • parietal bone (paired)

  • occipital

  • frontal sphenoid

  • ethmoid

• Facial bones

  • maxillary (paired)

  • palatine (paired)

  • zygomatic (paired)

  • vomer

  • inferior nasal conchae (paired)

  • mandible (paired)

  • lacrimal (paired)

  • nasal (paired)

Pharynx -

• shaped as on oval tube (larger at the sides than at the front-to-back)

• reaches from the base of the skull to the esophagus

• top of pharynx consists of connective tissue

• bottom of pharynx consists of muscle

• 3 primary divisions

  • nasopharynx

  • oropharynx

  • larengeopharynx

Velum -

• the soft palate and uvula

• leads to opening of oropharynx, which is through to faucial isthmus