Nose and Pharynx

MUDr.Pavel Hermann

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

Nose

Nasal cavity

Paranasal sinuses

Pharynx (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 or

nostrils, lead to the nasal cavities.

Nasal Cavity

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

Divided into right & left halves by the nasal septum.

Each half has a:

Roof

Lateral wall

Medial wall (septum)

Floor

Roof

Narrow & formed (anteroposteriorly) by the:

1. Nasal bone & cartilage

2. Frontal bone.

3. Cribriform plate of ethmoid bone

4. Body of sphenoid.

Floor

• Formed by the hard (bony) palate.

• Separates it from the oral cavity.

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3 2

1

Oral cavity

Medial Wall (Nasal Septum)

Osteo-cartilaginous partition between the two nasal cavities.

Formed by:

1. Septal cartilage.

2. Perpendicular plate of ethmoid bone.

3. Vomer.

Lateral Wall

Shows three horizontal bony projections, the

superior, middle & inferior conchae.

The cavity below each

concha is called a meatus and are named as superior, middle &

inferior corresponding to the conchae.

The small space above

the superior concha is the sphenoethmoidal (suprameatal) recess.

The conchae are covered by

respiratory epithelium and thus

increase the surface area of the

nasal cavity.

Sphenoethmoidal

recess Meati

Nose Olfactory mucosa:

Mucous membranes that contain smell

receptors.

Respiratory mucosa:

Pseudostratified ciliated columnar

epithelium containing goblet cells that

secrete mucus which traps inhaled

particles.

Nerve Supply

Olfactory mucosa supplied by olfactory nerves.

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

Autonomic fibers.

Lymphatic Drainage:

To the submandibular and the upper deep

cervical lymph nodes.

Paranasal sinuses

Paranasal Sinuses

Air filled cavities located in the 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 sinus

Hiatus 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:

Nasopharynx:

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

Oropharynx:

Middle part, communicates with the oral cavity through the oro-pharyngeal isthmus

Laryngopharynx:

Inferior part, communicates with the larynx through the laryngeal inlet

Nasopharynx 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.

Oropharynx 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.

Laryngopharynx

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 fossa

A small depression situated on either side of the laryngeal inlet

It is a common site for the lodging of foreign bodies.

Branches of internal laryngeal & recurrent laryngeal nerves lie deep to the mucous membrane of the fossa and are vulnerable to injury during removal of a foreign body.

Muscles of Pharynx

M

S

I

The muscles of the pharynx are

arranged in circular and

longitudinal layers

Circular (Constrictor)

Three muscles, overlap each other:

Superior, Middle & Inferior

Propel the bolus of food down into

the esophagus

Longitudinal Muscles

Three muscles:

Stylopharyngeus

Salpingopharyngeus

Palatpharyngeous

Elevate the larynx & pharynx

during swallowing

Sensory Nerve Supply • Nasopharynx: Maxillary nerve

• Oropharynx: Glossopharyngeal nerve

• Laryngopharynx: Vagus nerve

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

by the pharyngeal plexus.

• Stylopharyngeus is supplied by the glossopharyngeal nerve

Pharyngeal plexus A 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 supply: From branches of:

Ascending pharyngeal artery

Ascending palatine artery

Facial artery

Maxillary artery

Lingual artery

The Veins drain into pharyngeal venous plexus, which drains into the internal jugular vein

The Lymphatics drain into the:

Deep cervical

Retropharyngeal &

Paratracheal lymph nodes

Functions of the Pharynx

Provides a passageway for Air & Food

Moistens and warms entering air

Taste

Protection

Speech