BIOS: Anatomy of Speech

what are the 3 planes of reference?

saggital, horizontal / transverse, frontal / conronal

what is the sagittal plane

any vertical plane dividing the body into left and right

what is the midsaggital

a saggital plan that goes through the middle

what is the horiztontal plane? aka transverse

cuts across the body horizontally

• creates a superior and inferior

• 

what is the frontal plane? aka coronal?

vertically dividies into:

• front (anterior / ventral)

• back (posterior / ventral)

explain:
median:
lateral:

proximal

distal

dorsal

ventral

anterior

posterior

rostral

caudal

• Median = Symmetric in the middle

• Lateral = not on median

• Proximal = closer to the origin 

• Distal = further from the origin

• Dorsal = towards the spine (diff for quadrupeds) / towards back

• Ventral = towards the belly / towards front

• Anterior = towards the front

• Posterior = towards the back

• Rostral = towards the front of the head.

• Caudal = towards the tail / rear / coccyx

what is the dorsal part of the tongue?

the top part - as in its resting position, the tongue touches the roof of the mouth

what are the types of tissues

1. epithelial

2. connective

3. muscle

4. nervous

what is the def / features / examples of epithelial tissues?

covers body surfaces + body cavities

features: widely vary BUT no blood vessels, firmlt attatched to connective tissue and other side is exposed to: external environment/ inside of organ or vessel = lumen

• can also be strongly attatched to each other = barrier

e.g skin outer layer, trachea, sweat glands

explain the definition of connection tissues/ function and examples

makes up the majority of the body - protects body organs / binds organs together

• bones, fat, ligaments, tendons

what are key features of connective tissue?

• intercellular matrix = protein fibres, ground substances, fluid = non-cellular + spongy + absorbs water

• Resident cells that live/function within the tissue = repair, maintain + support

Fibres

• Collagen = high tensile strength → doesn’t stretch much (most abundant fibre e.g ligaments, tendons)

• Elastin = elastic, stretches without breaking (e.g arteries, ears)

• Reticular = thin collagen fibres, form delicate structural networks → supports cells + soft tissue (e.g immune tissues, liver)

Cells

• Fibrocyte = cells that help maintain fibres

• Chondrocyte = cells that maintain cartilage

• Osteocyte = cells that maintain cartilage 

Ground Substance

• Composed of gelatinous proteoglycan (protein + sugar) = can hold a lot of water = spongy = resists compressive forces

what are the 2 types of connective tissues?

1. loose connective tissue = lots of matrix, less fibre = fat

2. dense connective tissue = lots of fibre, less matrix = cartilage, bone

function / types of muscle tissue:

function: Responsible for movement (contraction)

types:

Skeletal Muscle = type of muscle tissue under voluntary control

• Usually attached bone to bone

• Muscles of facial expression 

• Origin is mainly up / proximal

• Insertion = mainly down / distal

Cardiac Muscle = for the heart + also involuntary control

Smooth Muscle= under involuntary control

nervous tissue function

Initiates and transmits nerve impulses through neurons and nerve cells

3 types of joints based on structural classificaiton

1. fibrous joints

2. cartilaginous joints

3. synovial joints

def / features / examples of fibrous joints

Def	Joints connected by by dense connective tissue > made up by tightly packed collagen
Features	Mostly immobile or very slightly movable The joints occur where bones have fused together which is why its immovable
Examples	Cranial suture, radioulnar

def / features / examples of cartilaginous joints

Features	Joints where bones are connected entirely by cartilage
Function	Slightly movable (usually - otherwise immovable)
Example	pubic symphysis, joints between vertebrae

def / function of synovial joints

Def	Freely movable joints where bones are separated by a synovial cavity enclosed by a joint capsule
Function	Allows for free mobility = various types of motion and directions

key features of synovial joints (6)

Articular capsule / joint capsule = strong connective tissue reinforced by ligaments

• Blends with periosteum = dense connective tissue that covers bone

• Strong + flexible = prevents dislocation

Synovial Membrane:

• Lines the articular capsule

• Thin, shiny and vascular

• Secretes synovial fluid

  

Synovial Fluid = decreases friction between the bones

• Plasma-like w/out clotting factors

• Low viscosity = well lubricated 

Joint Cavity/synovial cavity = space between articulating bones > filled with synovial fluid

Articular Cartilage

• hyaline cartilage that covers the two bones

• Glassy, smooth = decreases friction 

• Contains collagen (high tensile strength) + elastin = resists pressure

Some joints also have:

Articular disc of cartilage = allows for a better fit between bones by dividing the joint into 2 compartments

what are the 6 types of synovial joints and an example?

what is a ligament?

Ligament: a stabilising function that joins bone to bone 

• Proprioception: sense of we know where our body is

  • the muscles, ligaments will give signals to the sensory organs to help understand where the body is even if the eyes are closed

tell me about mechanical constraints:

• Aligned with line of pull → will constraint at the end of range

• Prevents unwanted movement + limits wanted movement

• When moving the ligament on the opposite side of the direction you move will become tighter hence limiting movement, while the ligament on the side of direction will become loose.

what is flexion and extension?

Flexion	the angle of the joint is decreased = the bones move towards each other (flexing the biceps)
Extension	the angles at the joint increases =  the bones of the joint move further away from each other

what is abduction and adduction?

Abduction	movement of a limb away from the midline of the body When you abduct someone you take it away from its rightful place
Adduction	movement of the limb towards the midline of the body

what is rotation?

Rotation

Turning a joint around its horizontal axis Medial Rotation: towards the middle Lateral Rotation: away from the middle

what is circumduction?

Circumduction

circular movement of a body part that makes a cone-shaped airspace e.g arm circles

what is mandibular elevation and depression?

Mandibular Elevation	Closing the mouth = LIFTING the mandible
Mandibular Depression	Opening the mouth = LOWERING the mandible - this is helpful for mastication = chewing

what is protraction and retraction?

Protraction	(of the jaw): the mandible moves anteriorly = pushes the chin forward
Retraction	The mandible moves posteriorly = pulls the jaw backward

what are the 2 types of muscle contraction?

1. isometric

2. isotonic

what is isometric contraction?

1. Isometric = contracting with the  same length/ no change

E.g sustaining vocal fold tension while holding a pitch

what is isotonic contraction and its two types?

• Isotonic = contracting with a changed length

  • Concentric = shortens + bulges 

  • Insertion moves CLOSER to origin

  • Closing lips for plosives (/p/ or /b/ sounds)

• Eccentric = lengthens + overcomes forces

  • Controlling jaw opening slowly

what is articulation in terms of anatomy?

​​articulate refers to the point where two or more bones, or bone and cartilage, come together to form a joint.

lateral view diagram:

inferior view of hard palate:

superior view of brain case

sutures of adult skull

superior view of sutures

posterior view of sutures

lateral oblique view of mandible

frontal view of mandible

posterior view of mandible

name the paired and unpaired bones in the neurocranium:

1. frontal bones (1)

2. parietal bones (2)

3. occipital (1)

4. temporal (2)

5. sphenoid (1)

6. ethmoid (1)

key features of frontal bone:

• houses frontal sinus

key features of parietal bone:

both bones joined medially by the saggittal suture

key feature sof the occipital bone

• Foramen magnum: allows spinal nerves etc to go from brain > spinal cord

• Articulates with the atlas (C1 vertebrae) = nodding / turning of head

  • Paired occipital condyles is joint to the atlas

key features of temporal bone:

5 distinct parts that fuse after birth (critical for hearing + balance structures)

1. Squamous = thin, flat-like part:

   1. Incl zygomatic process > articulates with zygomatic bone to create cheekbone (zygomatic arch)

   2. Attachment point for masseter m. (jaw movement)

2. Mastoid = posterior part

   1. Mastoid process = attachment site for neck muscles

3. Petrous = bumpy, dense area (hardest bone)

   1. Houses internal ear + internal acoustic meatus

4. Tympanic = u shaped plate

• Forms the areas of the external acoustic meatus (ear canal)

5. Styloid Process = pointed protrusion that extends down

• Anchor for muscles / ligaments of the tongue and larynx

key features of sphenoid bone:

“Bat-shaped”

• Centre: contains sphenoidal sinuses

• Has paired lesser wings + greater wings

• Pterygoid process = medial pterygoid plate

  • Hamulus (of medial…): allows for muscle to be hooked around > controls soft palate tension + ear tension

  • Lateral pterygoid plate: vital for jaw movement + TMJ mechanics

key features of the ethmoid bone:

“Spongy” + perforated: olfactory nerves pass through = smell

• Structure of nasal cavity

name the unpaired and paired bones in viscerocranium:

1. mandible (1)

2. vomer / nasal septum (1)

3. maxillae (2)

4. zygomatic bones (2)

5. nasal bones (2)

6. lacrimal bones (2)

7. palatine bones (2)

8. inferior nasal conchae (2)

what are key features of the mandible:
mandibular condyle, ramus, cornoid process, external oblique, angle, mental foramen, mental tubercle, alveolar part, mandibular foramen, mandibular canal, mylohoid line, mental spine

U-shaped horizontal body:

• Mandibular Condyle: rounded projection that articulates w temporal bone = Temporo-Mandibula Joint (TMJ) 

• Ramus of Mandible: extend upwards from mandible body 

• Coronoid Process: temporalis muscle attachment

• External Oblique Line: anchor for buccinator m. + m that depress lip/mouth

• Angle of Mandible

• Mental Foramen: for passage of nerves / vessels

• Mental Tubercle (external): structural integrity + m attachment sites

• Alveolar Part: the area where the tooth sits, (Alveoli = tooth socket)

• Mandibular Foramen: inferior alveolar nerves/artery/veins enter here

• Mandibular Canal: passage that protects + houses inferior alveolar nerve/artery/vein

• Mylohyoid line: attachment site of mylohyoid m > floor of mouth + swallowing/speech/depressing mandible

• Mental Spine: attachment site of m that allow tongue movement + swallowing

what is the vomer?

Line that divides the nose into separate cavities

key features of the maxillae?

Pair of pyramid-shaped bones > fused at midline = upper jaw

• Central part: maxillary sinus/paranasal sinus

• Alveolar process: thickened ridge > holds upper teeth

• Palatine process: horizontal plate > forms anterior ¾ of hard palate (roof of mouth)

• Frontal Process: articulates with frontal / nasal / lacrimal bones 

• Zygomatic Process: articulates with zygomatic bone

It is immovable - does not move

zygomatic bones - key features?

• Origin point for the masseter muscle (jaw closure)

• Attachment point for temporal fascia

what is the nasal bones?

forms the bridge of the nose

what is the lacrimal bones?

smallest , most fragile bones in facial skeleton

• Forms part of bony pathway that drains tears from the eye into the nasal cavity

what is the palatine bones?

Support key functions: separates oral + nasal cavities, facilitates speech, allows breathing + aids in chewing/swallowing

what is the inferior nasal conchae?

Filtres, heats and humidifies inhaled air due to its high surface area + vascularity 

• Sinus protection

what are the 5 cranial sutures and their locations?

Coronal	frontal bone + 2 parietal bones
Sagittal	Two parietal bones (along the midline)
Lambdoid	Parietal bones + occipital (at back of skull - inverted V shape)
Squamous	Temporal + parietal (on each side)
Metopic	Two frontal bones (from top of head to forehead)

what are the suture junctions (4) and their locations?

Asterion	b/w temporal, parietal, occipital bones
Pterion	b/w frontal, sphenoid, parietal and temporal (weakest part of the skull)
Bregma	B/w frontal and parietal bones  Location of anterior fontanelle in infancy
Lambda	b/w parietal and occipital bones Location of posterior fontanelle in infancy

paranasal sinuses:

paranasal sinuses lateral view

functions of sinuses:

Functions

Lightens the skull = reduces load on the neck Immune Function = epithelium lined with mucous producing cells + cells that produce immune factors > traps: pathogens, dust, particles for removal Cillia will move the particles away Shock Absorption: important for physical trauma Moisten + Humidifier inhaled air: protects respiratory tissue + prevents hoarseness Vocal Resonance: sounds vibrate + amplified in sinuses

Infection

If the sinus cavities become infected = sinusitis Blocked / fluid filled sinuses = reduced airflow → cause reduction in vocal resonance  Drainage occurs via networks

how is a cleft lip formed and its effect + treatment?

Cause	Tissues in baby’s face/ mouth don’t come together properly before birth Genes and environment may be causes, but not always
Effect	Physical malformations, Disrupts normal airflow + velopharyngeal closure, effects breathing, speech, swallowing Leads to: hypernasality, nasal air escape difficulty producing pressure constants (/p/, /b/. /t/, /k/) Compensatory articulation patterns: children use atypical places of articular to make up for structural limitations However, it is usually correct at least within first 12 months after term
Treatment/Management	Surgery, Speech Therapy, OT, ENT, Orthodontic care, neurologist, audiologist

name the cleft lips shape

what does ossification mean?

development of bone

what is the endochondral ossificaiton and its examples?

• Bone develops by replacing a pre-existing cartilage model

•  e.g cranial base, sphenoid, ethmoid, petrous temporal bone, basilar occipital region

what is membranous ossification?

• Bone develops directly from mesenchyme without a cartilage scaffold 

• e.g flat bones of cranial vault (frontal, parietal, squamous temporal, parts of occipital, most of facial bones in viscerocranium

mesenchyme = A loosely organised tissue that develops into connective + skeletal tissues

what is appositional growth?

bone increases in size by adding new layers to its outer surface by bone-making cells (osteoblasts)

what are fontanelles?

 a place b/w bone sin skull where ossification is NOT complete + sutures are not fully formed

• Accommodates for the baby’s growth + fuses as it grows

name these fontanelles?

how does sinuses change with age?

why does the angle of mandible change with age?

• Masticatory forces from muscles (attached to the jaw) affect the angle

• Angle is reduced when masticatory forces increase

how does the skull is as a newborn?

how is the skull as a child?

how is the skull as an adolecesent?

how is the skull as an adult?

how is the skull as an elderly?

what type of joint is the TMJ

synovial biaxial condylar joint

during the second stage of the mouth opening, what movement occurs?

anterior gliding of the condyle and disc onto the articular tubercle

which muscle primarily protrudes the mandible?

lateral pterygoid

which muscle rounds the mouth for the /oo/ sound?

orbicularis oris

which fontanelle corresponds to what cranial suture junction?

1. Bregma → anterior fontanelle

2. Lambda → Posterior fontanelle

3. Asteroid→ Mastoid Fontanelle

4. Pterion→ Sphenoid Fontanelle

Describe the TMJ:

Synovial, biaxial condylar joint formed b/w the mandible and the temporal bone

• Articular surfaces: articular tubercle + mandibular fossa with the condylar process (head)

• Has a loose but strong joint capsule

what is the TMJ’s function?

Allows movement of the mandible in relation to the maxilla (which is immobile)

• Mastication (chewing): approx jaw opens 50mm

• Speech: small but important movements

• Mandibular movement influences: lip posture, tongue position, oral cavity configuration, laryngeal height

what are the 4 key features of the TMJ and their description + functions:

1. Mandibular Condyle

2. Articular Tubercle + Mandibular Fossa

• articular tubercle = prevents the mandible from moving further upwards

3. Articular Disc: A wedge of fibrocartilage

• Has 2 synovial membranes that line each cavity

• Function: Increases congruency, range of motion + absorbs shock, divides the TMJ into superior / inferior compartments

• Shape: biconcave structure

• Attachments: Lateral pterygoid (anteriorally), Head of Mandible (anteriorly), Joint capsule (circumferentially)

4. Retrodiscal Tissue:band of connective tissue that contains nerves that attaches the articular disc (posterior)  → mandibular fossa + mandibular condyle

what are the two TMJ ligaments and its function?

1. Lateral (temporomandibular) ligament: strengthens TMJ joint capsule laterally + holds it taut in all movements

• Prevents inferoposterior condylar displacement or excess lateral movement

2. Stylomandibular ligament + Sphenomandibular ligament = accessory ligaments >> prevents excessive mandibular opening

what are the 3 key positions of the TMJ and the mandible?

• Resting Position: 3-4 mm teeth separation

• Close-packed position: molars firmly clenched, overlap incisors, mouth closed

  • the most stable position >> the muscles will try to act + ligaments make It taut

  • Provides max congruency, condyle lies within the articular fossa =  prevents further upward movement

• Closed Position: the joint capsule / natural ligaments / muscles: medial pterygoid, masseter and temporalis help keep the mandible and TMJ closed

what allows for the stability of the TMJ?

• Disc shape + attachments: Strongly attached, deformable pad improves mechanical fit, allows rotation + sliding movements to occur

• Ligament: Lateral ligament prevents dislocation 

• Muscles: Temporalis, lateral pterygoid provide dynamic stability + temp & masseter elevate mandible = stable position

what muscles are key in moving the mandible?

temporalis, masseter, lateral pterygoid, medial pterygoid, suparhyoid muscles = geniohyoid / mylohyoid / ant. belly of diagastric

for the temporalis muscle: what is its location / shape / origin / insertion / actions when contracted / its fibres and their actions?

Temporalis (fan-shaped muscle): (retraction - pos / elevation - rest)

• Origin: floor of temporal fossa/passes deep in the zygomatic arch/ insertion: coronoid process + ramus (ant.)

• Actions: elevation + retraction (when muscles contract)

  • Posterior Fibre: retraction (more horizontal fibres - travel > arch > coronoid process) 

  • Middle / Anterior Fibres: elevation (more vertical fibres)

for the masseter muscle: what is its location / shape / origin / insertion / actions when contracted / its fibres and their actions/ the two types?

Masseter (on the jaw) = stabilises the jaw  (elevation, partially protrusion + retraction) > primary jaw closer + chewing muscle

1. Superficial: 

   1. Origin: maxillary process on zygomatic bone / insertion: lateral surface of mandibular ramus + angle

   2. Action: Elevation + Protrusion

2. Deep

   1. Origin: zygomatic arch / insertion: ramus of mandible

   2. Action: Elevation + Retraction

= used for mastication

for the lateral pterygoid muscle: what is its location / shape / origin / insertion / actions when contracted / the two types?

Lateral Pterygoid (protrusion + depression)

1. Superior Head > Origin: greater wing of sphenoid / insertion: neck of mandible

2. Inferior Head > Origin: lateral pterygoid plate of sphenoid / insertion: neck of mandible

3. Actions: Protrusion, Depression

4. Purpose: controls slight forward movement for coordination with lips

for the medial pterygoid muscle: what is its location / shape / origin / insertion / actions when contracted / the two types?

Medial Pterygoid (elevation + protrusion) > has same direction as masseter so moves like it BUT a bit deeper, so not as impactful on mandible 

1. Superficial Head > origin: maxilla / insertion: internal surface of angle of mandible

2. Deep Head > origin: lateral pterygoid plate of sphenoid / insertion: internal mandible angle

3. Actions: elevation + protrusion

4. helps close the jaw + stabilise side-to-side movement

for the suprahyoid muscle: the types of muscles / what is its location / shape / origin / insertion / actions when contracted

Geniohyoid → superior to mylohyoid

Mylohyoid → covers floor of mylohyloid

Ant. Belly of Diagastric →inferior to mylohyoid

• Joined from “chin” >> joined to diagnostic fossa 

Main function: moves hyoid bone (which is above the larynx and is suspended within the body)

• If hyoid bone is fixed, the muscles will help depress the mandible

• If the mandible is fixed, the hyoid will be elevated

outline the process of the mouth opening and closing within the TMJ:

Resting Position: open packed jaw position, connective tissue is loose

• Medial + lateral pterygoid muscles relax

• Teeth not in contact, mouth slightly open

• Isometric contraction of temporalis + masseter

Rotation: first half of mouth opening (20-25mm) >> inferior compartment of TMJ

• Condylar process rolls anteriorly

• Eccentric contraction of temporalis

• Inferior portion of lateral pterygoid tenses

• Superior lateral pterygoid relaxes

Translation: second half of mouth opening >> superior compartment of TMJ

• Disc + condylar process glide anteriorly

• Eccentric contraction of temporalis

• Superior + inferior lateral pterygoid contracts concentrically (shortens)

• Connective tissue taut posteriorly

Closure: 

• Disc + condylar process glide posteriorly

• Masseter (+ post temporalis, eccentric lateral pterygoid)

• Connective tissue returns to rest

name key facial muscles for speech

orbicularis oris, buccinator, lip muscles, upper lip elevators, lower lip depressors, mentalis

what is the orbicularis oris?

circular muscle that surrounds the mouth

For Speech: Closes the lips / rounds the lips / protrudes the lips 

• Bilabial sounds: /p/ /b/ /m/ = requires 2 lips to close together

• Labiodental Sounds: /f/ /v/ > requires controlled lip positioning against teeth

• Rounded Vowels: /u/ (food), /o/ (go) > requires lip rounding + protrusion

If weak / impaired = difficulty in closing or rounding lips

what is the buccinator?

Muscles in the cheek

For Speech: keeps cheeks tight against teeth / prevents air from collecting in cheeks while speaking / maintains inner mouth pressure = builds up air pressure then releases it 

• Plosives (stops): /p/ /b/ /t/ /k/ = need air pressure buildup b4 the sound 

• Fricatives: /s/ /f/ /v/ = controlled airflow thru narrow space

If weak / impaired = air may escape into the cheeks > reduces speech precision