dr. sami zaqout faculty of medicine...

Dr. Sami Zaqout Faculty of Medicine IUG

Nasal

Cavity

External

Nose

The Nose


External Nose


Blood and Nerve Supplies of the External Nose

• Blood Supply of the External Nose – The skin of the external nose

• Branches of the ophthalmic and the maxillary arteries

– The skin of the ala and the lower part of the septum • Branches from the facial artery

• Nerve Supply of the External Nose • The infratrochlear and external nasal branches of the

ophthalmic nerve

• The infraorbital branch of the maxillary nerve


Nasal Cavity


Choanae


Nasal Cavity - Floor


Nasal Cavity - Roof


Nasal Cavity - Lateral Wall


Nasal Cavity - Medial Wall


Ethmoid bone


Mucous Membrane of the Nasal Cavity

• The vestibule is lined with modified skin and has coarse hairs.

The area above the superior concha is lined with olfactory mucous membrane.

The lower part of the nasal cavity is lined with respiratory mucous membrane.


Function of Warm Blood and Mucus of Mucous Membrane

• The presence of warm blood in the venous plexuses serves to heat up the inspired air as it enters the respiratory system.

• The presence of mucus on the surfaces of the conchae traps foreign particles and organisms in the inspired air.


Nerve Supply of the Nasal Cavity.


Arterial Supply to the Nasal Cavity


Venous drainage of the nasal cavities


Lymphatic drainage of the nasal cavities


Examination of the Nasal Cavity

• It should be remembered that the nasal septum is rarely situated in the midline.

• A severely deviated septum may interfere with drainage of the nose and the paranasal sinuses.


Trauma to the Nose

• Fractures involving the nasal bones are common.

• Blows directed from the front may cause one or both nasal bones to be displaced downward and inward.

• Lateral fractures also occur in which one nasal bone is driven inward and the other outward; the nasal septum is usually involved.


Infection of the Nasal Cavity

• Organisms may spread via the nasal part of the pharynx and the auditory tube to the middle ear.

• It is possible for organisms to ascend to the meninges of the anterior cranial fossa, along the sheaths of the olfactory nerves through the cribriform plate, and produce meningitis.


Foreign Bodies in the Nose

• Foreign bodies in the nose are common in children.

• The presence of the nasal septum and the existence of the folded, shelflike conchae make impaction and retention of balloons, peas, and small toys relatively easy.


Nose Bleeding - Epistaxis

• The most common cause is nose picking.

• The bleeding may be arterial or venous, and most episodes occur on the anteroinferior portion of the septum and involve the septal branches of the sphenopalatine and facial vessels.


The Paranasal Sinuses


Functions of Paranasal Sinuses

Act as resonators to the voice

Reduce the weight of the skull


Maxillary Sinus • The maxillary sinus is pyramidal in shape and located within

the body of the maxilla behind the skin of the cheek. The roof is formed by the floor of the orbit The floor is related to the roots of the premolars and molar

teeth.


Frontal Sinuses • The two frontal sinuses are contained within the frontal

bone. • They are separated from each other by a bony septum. • Each sinus is roughly triangular, extending upward above

the medial end of the eyebrow and backward into the medial part of the roof of the orbit.


Sphenoidal Sinuses • The two sphenoidal sinuses lie within the body of the

sphenoid bone


Ethmoid Sinuses • The ethmoidal sinuses are anterior, middle, and posterior

and they are contained within the ethmoid bone, between the nose and the orbit.

• They are separated from the latter by a thin plate of bone so that infection can readily spread from the sinuses into the orbit.


Paranasal Sinuses and Their Site of Drainage Into the Nosea


Sinusitis


Sinusitis

• The frontal sinus is innervated by the supraorbital nerve, which also supplies the skin of the forehead and scalp as far back as the vertex.

• The maxillary sinus is innervated by the infraorbital nerve and, in this case, pain is referred to the upper jaw, including the teeth.


Examination of the Paranasal Sinuses


Transillumination - Radiologic examination


The Larynx Protective sphincter at the inlet of the air passages.

Responsible for voice production.

• Lies at the level of the fourth, fifth, and sixth cervical vertebrae.


Larynx


Cartilages of the Larynx

Thyroid cartilage

Cricoid cartilage

Arytenoid cartilages

Cuneiform cartilages

Corniculate cartilages

Epiglottis


Thyroid cartilage


Cricoid cartilage


Arytenoid cartilages


Corniculate and cuneiform cartilages


Epiglottis


Membranes and Ligaments of the Larynx

Thyrohyoid membrane

Cricotracheal ligament

Quadrangular membrane

Cricothyroid ligament


Thyrohyoid membrane + Cricotracheal ligament


Quadrangular membrane


Cricothyroid ligament.


Inlet + Cavity of the Larynx


Vestibular Fold

• The vestibular fold is a fixed fold on each side of the larynx.

• It is formed by mucous membrane covering the vestibular ligament and is vascular and pink in color.


Vocal Fold (Vocal Cord)

• The vocal fold is a mobile fold on each side of the larynx and is concerned with voice production.

• It is formed by mucous membrane covering the vocal ligament and is avascular and white in color.


Vocal Fold (Vocal Cord)

• The gap between the vocal folds is called the rima glottidis or glottis.

• The glottis is bounded in front by the vocal folds and behind by the medial surface of the arytenoid cartilages.

• The glottis is the narrowest part of the larynx and measures about 2.5 cm from front to back in the male adult and less in the female.


In children the lower part of the larynx within

the cricoid cartilage is the narrowest part


Laryngeal Cavity - Laryngoscope

dr. sami zaqout faculty of medicine...

Documents