Nose and Pharynx

Dr. Sama ul Haque

Objectives

Discuss the anatomical structure of nose.

Define Paranasal sinuses.

Describe the anatomical structure of pharynx.

Enlist the extrinsic and intrinsic muscles of the

pharynx with their nerve supply and actions.

Organization and Functions of the Respiratory System

Consists of an upper respiratory tract (nose to larynx) and a lower respiratory tract (trachea onwards).

Conducting portion transports air. - includes the nose, nasal cavity, pharynx,

larynx, trachea, bronchi and bronchioles. Respiratory portion carries out gas exchange. - composed of small airways called respiratory

bronchioles and alveolar ducts as well as air sacs called alveoli.

Upper Respiratory Tract

NoseNasal cavityParanasal sinusesPharynx (throat)Larynx

Upper Respiratory Tract

Structure of the Nose Nose, is the only visible part of

the respiratory system and serves as the entrance to the respiratory tract

The nose has two cavities, separated from one another by a wall called the septum.

The external openings, known as external (anterior) nares external (anterior) nares oror nostrils, nostrils, lead to the lead to the nasal nasal cavities.cavities.

Nasal CavityNasal Cavity

Extends from the Extends from the external (anterior) external (anterior) nares nares to the to the posterior nares posterior nares (choanae).(choanae).

Divided into right & Divided into right & left halves by the left halves by the nasal septum.nasal septum.

Each half has a:Each half has a: RoofRoof Lateral wallLateral wall Medial wall Medial wall

(septum)(septum) FloorFloor

RoofRoof Narrow & formed Narrow & formed

(anteroposteriorly) by (anteroposteriorly) by the: the:

1.1. Nasal bone & Nasal bone & cartilagecartilage

2.2. Frontal bone.Frontal bone.

3.3. Cribriform plate of Cribriform plate of ethmoid boneethmoid bone

4.4. Body of sphenoid.Body of sphenoid.

FloorFloor• Formed by the Formed by the hard (bony) palate.hard (bony) palate.• Separates it from the oral cavity. Separates it from the oral cavity.

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Hard PalateHard Palate

Oral cavityOral cavity

Medial Wall Medial Wall (Nasal (Nasal Septum)Septum)

Osteo-Osteo-cartilaginouscartilaginous partition partition between the between the two nasal two nasal cavities.cavities.

Formed by:Formed by:1.1.Septal Septal

cartilage.cartilage.2.2.Perpendicular Perpendicular

plate of plate of ethmoid bone.ethmoid bone.

3.3.VomerVomer..

Lateral WallLateral Wall Shows three horizontal Shows three horizontal

bony projections, the bony projections, the superiorsuperior,, middlemiddle && inferiorinferior conchae.conchae.

The cavity below each The cavity below each concha is called a concha is called a meatusmeatus and are named and are named as as superiorsuperior, , middlemiddle & & inferiorinferior corresponding corresponding to the conchae.to the conchae.

The small space above The small space above the superior concha is the superior concha is the the sphenoethmoidal sphenoethmoidal (suprameatal) recess.(suprameatal) recess.

The conchae are covered by The conchae are covered by respiratory epithelium and thus respiratory epithelium and thus

increase the surface area of the increase the surface area of the nasal cavity.nasal cavity.

Inferior concha

Inferior concha

SuperiorSuperior conchaconcha

middle concha

middle concha

Sphenoethmoidal Sphenoethmoidal recessrecessMeatiMeati

SphenoethmoidaSphenoethmoidal recessl recess

sphenoidal sinussphenoidal sinus

Superior meatusSuperior meatus posterior ethmoidal sinusposterior ethmoidal sinus

Middle meatusMiddle meatus middle ethmoidal, maxillary, frontal & the middle ethmoidal, maxillary, frontal & the anterior ethmoidal sinusesanterior ethmoidal sinuses

Inferior meatusInferior meatus nasolacrimal duct.nasolacrimal duct.

The recess & meati receive the openings of the paranasal sinuses & naso-lacrimal duct.

NoseOlfactory mucosa:

Mucous membranes that contain smell

receptors.

Respiratory mucosa:

Pseudostratified ciliated columnar

epithelium containing goblet cells that

secrete mucus which traps inhaled

particles.

Nerve SupplyNerve Supply Olfactory Olfactory

mucosamucosa supplied by supplied by olfactory olfactory nerves.nerves.

Nerves of Nerves of general general sensation are sensation are derived from derived from ophthalmicophthalmic & & maxillary maxillary nerves.nerves.

Autonomic Autonomic fibers.fibers.LymphaticLymphatic DrainageDrainage::

To the To the submandibularsubmandibular and the and the upper deep upper deep cervicalcervical lymph nodes. lymph nodes.

Paranasal sinuses

Paranasal Sinuses Air filled cavities Air filled cavities located in the located in the

bones around the nasal cavity bones around the nasal cavity Frontal, ethmoidal, sphenoidal, maxillary.

Lined by respiratory mucosa which is continuous with the mucosa of the nasal cavity

Decrease skull bone weight.

Warm, moisten and filter incoming air.

Add resonance to voice.

Communicate with the nasal cavity by ducts for drainage

Drainage of the Paranasal Sinuses Sphenoethmoidal recess: Sphenoidal air sinus Superior meatus:

Posterior ethmoidal air sinus Middle meatus :Bulla ethmoidalis: Middle ethmoidal air sinusHiatus semilunaris: Frontal air sinus Maxillary air sinus Anterior ethmoidal Inferior meatus: Nasolacrimal duct

Blood supply of the nasal cavity:-

Functions of the Nose

Provides an airway for respiration

Moistens and warms entering air

Filters and cleans inspired air

Resonating chamber for speech

Detects odors in the air stream

Pharynx Common space used by both the respiratory

and digestive systems. Commonly called the throat. Walls are lined by a mucosa and contain

skeletal muscles that are primarily used for swallowing.

Partitioned into three adjoining regions:

Nasopharynx

Oropharynx

Laryngopharynx

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Divisions of the Pharynx

Divided into three parts:Divided into three parts: NasopharynxNasopharynx: :

Superior part, Superior part, communicates with the communicates with the nasal cavity through nasal cavity through posterior nasal aperturesposterior nasal apertures

OropharynxOropharynx: : Middle part, communicates Middle part, communicates

with the oral cavity through with the oral cavity through thethe oro-pharyngeal oro-pharyngeal isthmusisthmus

LaryngopharynxLaryngopharynx: : Inferior part, communicates Inferior part, communicates

with the larynx through the with the larynx through the laryngeal inletlaryngeal inlet

NasopharynxNasopharynx Located directly posterior to the

nasal cavity and superior to the soft palate, which separates the oral cavity.

Normally, only air passes through.

In the lateral walls of the nasopharynx, paired auditory/eustachian tubes connect the nasopharynx to the middle ear.

Posterior nasopharynx wall also houses a single pharyngeal tonsil (commonly called the Adenoids).

OropharynxOropharynx Middle pharyngeal region. Lies immediately posterior to

the oral cavity. Common respiratory and

digestive pathway through which both air and swallowed food and drink pass.

Lymphatic organs here provide the first line of defense against ingested or inhaled foreign materials. Palatine tonsils are on the lateral wall between the arches, and the lingual tonsils are at the base of the tongue.

LaryngopharynxLaryngopharynx Inferior, narrowed

region of the pharynx.

Terminates at the

superior border of the esophagus and the epiglottis of the larynx.

Permits passage of both food and air.

Piriform fossaPiriform fossa

A small depression situated A small depression situated on either side of the on either side of the laryngeal inletlaryngeal inletIt is a It is a common site common site for the for the lodging of foreign bodies.lodging of foreign bodies.Branches of Branches of internal internal laryngeallaryngeal & & recurrent recurrent laryngeal nerves laryngeal nerves lie deep to lie deep to the mucous membrane of the mucous membrane of the fossa and are vulnerable the fossa and are vulnerable to injury during removal of a to injury during removal of a foreign body.foreign body.

Muscles of PharynxMuscles of Pharynx

MM

SS

II

The muscles of the pharynx are arranged in circular and longitudinal layers

Circular (Constrictor) Three muscles, overlap each other: Three muscles, overlap each other:

SuperiorSuperior, , MiddleMiddle & & InferiorInferior Propel the bolus of food down into

the esophagus

Longitudinal Muscles Three muscles: Three muscles:

Stylopharyngeus Salpingopharyngeus Palatpharyngeous

Elevate the larynx & pharynx during swallowing

Sensory Sensory Nerve SupplyNerve Supply• NasopharynxNasopharynx: : Maxillary nerveMaxillary nerve• OropharynxOropharynx: : Glossopharyngeal nerveGlossopharyngeal nerve• LaryngopharynxLaryngopharynx: : Vagus nerveVagus nerve

MotorMotor Nerve Supply Nerve Supply : : • All the muscles of pharynx, except the stylopharyngeus, are supplied All the muscles of pharynx, except the stylopharyngeus, are supplied

by the by the pharyngeal plexus. pharyngeal plexus. • Stylopharyngeus is supplied by the Stylopharyngeus is supplied by the glossopharyngeal nerve glossopharyngeal nerve

Pharyngeal plexusA network of nerves (sensory, motor & sympathetic) located on the surface of the middle pharyngeal constrictor muscle, is formed by the:

• Pharyngeal branches of glossopharyngeal nerve (sensory)• Pharyngeal branch of vagus nerve (motor)• Sympathetic fibers from superior cervical ganglion (vasomotor)

Arterial supplyArterial supply: : From branches of:From branches of: Ascending pharyngeal arteryAscending pharyngeal artery Ascending palatine arteryAscending palatine artery Facial arteryFacial artery Maxillary arteryMaxillary artery Lingual arteryLingual artery

TheThe VeinsVeins drain into drain into pharyngeal venous plexuspharyngeal venous plexus, which , which drains into the drains into the internal jugular veininternal jugular vein

TheThe LymphaticsLymphatics drain into the: drain into the: Deep cervicalDeep cervical Retropharyngeal &Retropharyngeal & Paratracheal lymph nodesParatracheal lymph nodes

Functions of the Pharynx

Provides a passageway for Air & Food

Moistens and warms entering air

Taste

Protection

Speech