Anatomy and Physiology

Nasal Bridge

The saddle-shaped area of the nose that includes the nasal root and the lateral (side) aspects of the nose. It forms the upper bony portion of the nose.

Nasal Tip

The most anterior, projecting portion of the nose. Its position and projection are supported by the columella and underlying cartilage.

Columella

The tissue that separates the two nostrils externally. It acts like a supporting column for the nasal tip and should ideally be straight and supported by a straight nasal septum.

Naris (plural: nares) / nostril

The external openings of the nose through which air enters and exits. A single opening is called a naris, while both openings together are the nares.

Ala Nasi

The curved outer side ("wing") of a nostril.

Alar Rims

The curved outer edges that surround the openings of the nostrils.

Alar Base

The area where the ala nasi joins the upper lip.

Nasal Sill

The base or floor of the nostril opening. It forms the lower border of the nostril.

Vomer

Perpendicular structure that fits in median palatine suture groove, below septal cartilage and above hard palate

Turbinates (nasal conchae)

• Curved, shelf-like bony structures inside the nasal cavity that are covered by mucous membrane.

• They project from the lateral walls of the nose into the nasal cavity.

• Their functions are to:

  • Filter inhaled air

  • Warm inhaled air

  • Humidify inhaled air

  • Direct airflow toward the olfactory region for smell

Superior Turbinate

• The highest and smallest turbinate.

• Located near the roof of the nasal cavity.

• Helps direct airflow toward the olfactory (smell) receptors

Middle Turbinate

• Located below the superior turbinate.

• Forms part of the lateral wall of the nasal cavity.

• Helps regulate airflow and drainage from several sinuses.

Inferior Turbinate

• The largest and lowest turbinate.

• Plays a major role in warming, humidifying, and filtering inspired air.

Meatuses

• Passageways or spaces located directly beneath each turbinate.

• Air flows through these spaces during breathing.

Superior Nasal Meatus

• Space beneath the superior turbinate.

• Allows airflow through the upper portion of the nasal cavity.

Middle Nasal Meatus

• Space beneath the middle turbinate.

• Important drainage pathway for several paranasal sinuses.

Inferior Nasal Meatus

• Space beneath the inferior turbinate.

• The largest nasal passageway for airflow.

Paranasal Sinuses

• Air-filled cavities located within the bones of the face and skull.

• Connected to the nasal cavity through small openings called ostia.

• Four paired sinuses:

  1. Frontal sinuses – in the forehead

  2. Ethmoid sinuses – between the eyes

  3. Maxillary sinuses – beneath the cheeks

  4. Sphenoid sinuses – deep within the skull

Incisive Foramen

• an opening located at the junction between the premaxilla (the triangular bone at the very front of the hard palate) and the maxillary bones

• the starting point of embryological development of lip and palate

• It marks the boundary between two major developmental regions:

  • the primary palate (formed from the premaxilla)

  • the secondary palate (formed from the palatal shelves of the maxilla)

Sphenoid and Temporal Bones

• Cranial bones that provide the structural base and attachment sites for muscles involved in velopharyngeal function.

Medial & Lateral Pterygoid Plates

• Thin bony projections of the pterygoid process of the sphenoid bone

• These plates form part of the posterior nasal and oral framework

• Serve as attachment sites for muscles of the pharynx and soft palate, contributing to velopharyngeal movement.

Pterygoid Hamulus

• A hook-like projection at the inferior end of the medial pterygoid plate

• Acts as a pulley for the tendon of the tensor veli palatini muscle, allowing the muscle to change direction and assist in tensing the soft palate and opening the eustachian tube.

Adenoid Pad

• A mass of lymphoid tissue located on the posterior pharyngeal wall in the nasopharynx, just behind the velum (soft palate)

• Part of the immune system and help produce antibodies, especially in early childhood

• in young children, often large and can assist with velopharyngeal closure, contributing to what is called velophadenoidal closure.

Cleft Risk for chronic otitis media

• In individuals with a cleft palate, the muscles of the velopharyngeal mechanism (especially the tensor veli palatini) are abnormally positioned or function poorly, so the eustachian tube does not open effectively.

This leads to:

• Poor ventilation of the middle ear

• Fluid buildup (otitis media with effusion)

• Increased risk of recurrent ear infections

Child risk for Ear Infection

• Eustachian tube for drainage horizontal

• becomes more vertical moving to adulthood

Lateral Pharyngeal Walls

• Side walls of the pharynx that form part of the velopharyngeal valve.

• Structurally, they are composed of muscle and soft tissue

Function:

• Move medially (inward) during velopharyngeal closure

• Close against the velum (soft palate) or, in some cases, meet in midline

• Provide an important contribution to closure, though the degree of movement varies among individuals

Posterior Pharyngeal Wall

• Back wall of the pharynx, forming the posterior boundary of the velopharyngeal valve.

Function:

• May move slightly anteriorly (forward) during velopharyngeal closure

• Serves as the contact surface for the velum in many individuals

• Contributes less to closure compared to the velum and LPWs

Passavant’s ridge

Bulge of muscle on the posterior pharyngeal wall during speech; occurs in some normal and abnormal speakers

Velar Dimple

• A visible indentation in the midline of the oral (inferior) surface of the velum (soft palate) seen during speech or phonation.

Structure & Cause:

• Formed by the interdigitation (blending) of the levator veli palatini muscles in the midline

• Represents the point where these muscles pull the velum upward and backward

Velopharyngeal Function

• Seperates the nasal cavity from the oral cavity

• Regulates and directs transmission of sound energy and airflow into the oral and nasal cavities

• Particularly important for production of “pressure- sensitive” consonant sounds (plosives, fricatives, and affricates) and all vowels

• Closes off nose and builds pressure for swallowing

Levator Veli Palatini (Velar “Sling”)

• Primary muscle that elevates the velum during speech

• Forms a muscular sling in the midline, pulling the soft palate upward and backward for velopharyngeal closure

Superior Constrictor (Pharyngeal Ring)

• Muscle of the pharyngeal wall that constricts (narrows) the pharynx.

• Helps move the lateral pharyngeal walls inward to aid in velopharyngeal closure.

Palatopharyngeus (Posterior Faucial Pillar)

• Runs in the posterior faucial pillars

• Pulls the lateral pharyngeal walls inward and helps bring them against the velum during closure.

Palatoglossus (Anterior Faucial Pillar)

• Found in the anterior faucial pillars

• Responsible for lowering the velum quickly for nasal sounds and helping open the velopharyngeal port.

Musculus Uvulae

• Midline muscle that creates a bulge (velar eminence) on the nasal surface of the velum

• Adds bulk and stiffness for a tighter velopharyngeal seal.

Tensor Veli Palatini

• Does not elevate the velum

• Tenses the soft palate and opens the eustachian tube during swallowing for middle ear ventilation.

Coronal Velopharyngeal Closure

Velum moves posteriorly to contact the posterior pharyngeal wall (most common, ~70%).

Circular Velopharyngeal Closure

Velum, lateral pharyngeal walls, and posterior wall all contribute equally → forms a sphincter-like closure (~25%)

Sagittal Velopharyngeal Closure

Lateral pharyngeal walls move medially to meet in midline with minimal velar movement (least common, ~5%).

Pneumatic vs Non‑Pneumatic Activities

Non‑pneumatic activities (no airflow):

• Examples: swallowing, gagging, vomiting

• Velopharyngeal closure is very high and tight

• Closure is firm and along entire pharynx

  • Purpose: Prevent material from entering the nasal cavity

Pneumatic activities (use airflow/pressure):

• Examples: speech, blowing, singing, sucking

• Closure is lower in the pharynx

• Requires precise, rapid, coordinated movement

  • Purpose: Direct airflow and sound between oral and nasal cavities

Respiration for Speech Sounds

High-pressure sounds

• Plosives (p, b, t, d, k, g)

• Fricatives (f, v, s, z, ʃ, Θ, ð)

• Affricates (ʧ, ʤ)

Low-pressure sounds

• Liquids (l, r)

• Glides (w, j)

No-pressure sounds

• Nasals (n, m, ŋ)

Lip Anatomy

• Philtrum: Midline vertical groove between nose and upper lip

• Philtral ridges (columns): Raised borders of philtrum; fusion lines

• Cupid’s bow: Double peak shape of upper lip border

• White roll: Raised outline of the lip border

• Vermilion: Red portion of the lips

• Labial tubercle: Midline fullness of upper lip