WEEK 1: UPPER RESPIRATORY TRACT ANATOMY Flashcards
Outline parts that make up the upper respiratory tract
The upper respiratory tract includes the nose, nasal cavity, paranasal sinuses, pharynx and the portion of the larynx above the vocal cords.
State the parts that make up the lower respiratory tract
The lower respiratory tract includes the larynx below the vocal cords, the trachea, bronchi, bronchioles and the lungs.
State the 12 cranial bones of the nasal cavity, 4 paired and 4 unpaired
Nasal, Maxilla, Palatine, Lacrimal (PAIRED)
Sphenoid, Vomer, Ethmoid, Frontal (UNPAIRED)
Name the structures visible on the LATERAL WALL of the Nasal cavity
*Conchae: Superior, middle and inferior
*Meatus: Superior middle and inferior
*Choana: the opening between the nasal cavity and the nasopharynx
*Torus tubarius
*Sphenoethmoidal recess
Describe the following:
*Nasal vestibule
*Limen nasi
Nasal vestibule: The nasal vestibules are the two entry points into the nasal cavity.
Limen nasi: boundary between the nasal cavity proper and the vestibule
State the functions of the conchae
The lateral walls of the nasal cavity contain three bony projections called nasal conchae (superior, middle and inferior),
- which increase the surface area of the nasal cavity.
*The nasal conchae also disrupt the laminar flow of air, making it slow and turbulent, thereby helping to humidify and warm up the air to body temperature.
State the function of the meatus
They acts as a pathway of air to flow
What are functions of the nasal cavity?
*Olfaction
*Filtration
*Humidification and temperature Respiration
*Drains paranasal sinuses
What is the medial wall of the nasal cavity called?
nasal septum
Name the 3 main components that make up the nasal septum
*Septal cartilage, Vomer, perpendicular plate of the ethmoidal bone
What is Kieselbach area?
Kieselbach’s area is an anastomotic arterial network of four or five arteries in the nose supplying the nasal septum.
It is a common site for nose bleeds.
Describe the blood supply to the nasal septum.
*INTERNAL CAROTID supplies ophthalmic which forms Anterior and posterior ethmoidal arteries
*EXTERNAL CAROTID gives:
-MAXILLARY ARTERY which gives Sphenopalatine artery which enters at sphenopalatine foramen
-MAXILLARY also gives Greater palatine artery
-FACIAL ARTERY fives rise to superior labial branch of facial artery
Where are the paranasal sinuses found?
List all the paranasal sinuses
*The paranasal sinuses are air-filled extensions of the nasal cavity.
*There are four paired sinuses – named according to the bone in which they are located – maxillary, frontal, sphenoid and ethmoid
State the functions of the paranasal sinuses.
*Lightening the weight of the head
*Supporting immune defense of the nasal cavity
*Humidifying inspired air
*Increasing resonance of the voice
Describe where each of the paranasal sinuses drain.
1.Frontal sinus: Frontonasal duct—- Ethmoidal infundibulum—-Middle nasal meatus—- Semilunar meatus
2.Maxillary sinus: Maxillary ostium—Semilunar hiatus—Middle nasal meatus
3.Ethmoidal sinus: divided into 3 groups:
-Anterior, Middle, Posterior
*Anterior: ethmoid infundibulum—Middle nasal meatus
*Middle: Form ethmoid bulla —Middle nasal meatus
*Posterior: Superior nasal meatus
4.Sphenoid: Sphenoethmoidal recess—Superior nasal meatus
5.Lacrimal duct: inferior nasal meatus
A patient is seen in the neurosurgery clinic with an MRI-confirmed pituitary adenoma. Surgical resection of the adenoma is planned.
When considering the surgical approach, which paranasal sinus provides access the pituitary gland?
Sphenoid
Which of the following is not an ethmoid sinus?
Anterior
Middle
Medial
Posterior
Medial
Which is the largest of the paranasal sinuses?
Frontal sinus
Maxillary sinus
Ethmoid sinus
Sphenoid sinus
Maxillary
Which sinus is prone to sinusitis and presents with a blocked nose?
Maxillary sinus
Why is the maxillary sinus difficult to drain?
Because of the position of the ostia, Gravity cannot drain the maxillary sinus when the head is erect.
Describe blood supply and nerve supply to each sinus
FRONTAL: Supra orbital nerve (a branch of the ophthalmic nerve), and arterial supply is via the anterior ethmoidal artery (a branch of the internal carotid).
MAXILLARY: anterior, middle, and posterior superior alveolar nerves, branches of the maxillary nerve (CN V2)
Blood supply: Superior alveolar nerve which is a branch of the maxillary nerve.
ETHMOIDAL: Anterior and posterior ethmoidal branches of the Naso ciliary nerve and the maxillary nerve. The anterior and posterior ethmoidal arteries are responsible for arterial supply.
SPHENOIDAL: Posterior ethmoidal nerve (a branch of the ophthalmic nerve), and branches of the maxillary nerve. They receive blood supply from pharyngeal branches of the maxillary arteries.
Describe the boundaries of the nasal cavity
ROOF: Sphenoid bone
FLOOR: Palatine process of the maxilla and horizontal plate of the palatine bone
LATERAL WALLS: Nasal conchae
MEDIAL: Nasal septum
Describe the clinical relevance of the nasal cavity.
*Nasal fracture
*Nasal septum deviation
*Rhinitis:
*Epistaxis
*Sinusitis
*Infection of the ethmoidal cells can result in blindness as some posterior ethmoidal cells lie close to the optical canal, which gives passage to the optic nerve causing optic neuritis
State the parts of the ethmoid bone
*Cribriform plate, crista galli, perpendicular plate
