Transcript 1_Nose and Pharynx_3

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
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
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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)
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3
by the:
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1. Nasal bone &
cartilage
2. Frontal bone.
3. Cribriform plate
of ethmoid bone
Oral cavity
4. Body of
sphenoid.
Floor
• Formed by the hard (bony) palate.
• Separates it from the oral cavity.
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Medial Wall
(Nasal Septum)
 Osteocartilaginous
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.
Meati
Sphenoethmoidal
recess
The conchae are covered by
respiratory epithelium and thus
increase the surface area of the
nasal cavity.
The recess & meati receive the openings of the paranasal
sinuses & naso-lacrimal duct.
Sphenoethmoidal
recess
sphenoidal sinus
Superior meatus
posterior ethmoidal sinus
Middle meatus
middle ethmoidal, maxillary, frontal & the
anterior ethmoidal sinuses
Inferior meatus
nasolacrimal duct.
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
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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

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
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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.
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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
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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
 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
S
M
I
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Sensory Nerve Supply
•
•
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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
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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
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Taste
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Protection

Speech