Nose and Pharynx - orl.lf1.cuni.cz · Structure of the Nose Nose, is the only visible part of the...
Transcript of Nose and Pharynx - orl.lf1.cuni.cz · Structure of the Nose Nose, is the only visible part of the...
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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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