Anatomy 15 Flashcards
What forms the first part of the respiratory tract?
Left and right nasal cavities
What does mucosa in the upper part of the nasal cavity contain?
Olfactory receptors
What do the axons of the olfactory receptors form?
Form the olfactory nerves
What are the left and right nasal cavities separated from each other by?
A thin midline septum, formed of cartilage and bone.
When the head is bisected, the septum is seen on one half only
What are the left and right nasal cavities separated from the oral cavity inferiorly by?
Hard Palate
What are the left and right nasal cavities separated from the brain superiorly by?
Bone
What does the nasal cavity communicate with?
Communicates with the nasopharynx posteriorly
The nasal cavity also communicates with the paranasal sinuses, which are cavities within the skull bones
What is the midline nasal septum formed of?
Cartilage anteriorly and two thin plates of bone posteriorly
What does the perpendicular plate of the ethmoid bone form?
Forms the superior part of the posterior septum
What does the vomer form?
Forms the inferior part of the posterior septum
What does the lateral wall of the nasal cavity bear?
3 projections of bone:
Superior
Middle
Inferior conchae (Latin = shell), or turbinates.
What is the space inferior to the turbinates in the lateral wall of the nasal cavity?
Meatuses:
- the superior meatus lies inferior to the superior concha
- the middle meatus lies inferior to the middle concha
- the inferior meatus lies inferior to the inferior concha
● As inspired air travels through the meatuses it is warmed, humidified, and filtered.
What is the nasal cavity separated from the cranium and brain by?
The cribriform plate.
The cribriform plate is a delicate section of bone that is perforated with tiny holes (like a sieve)
The axons of olfactory neurones pass through these perforations to form the olfactory nerves, which travel to the brain
Where are olfactory receptors located?
In the spheno-ethmoidal recess in the upper nasal cavity, between the superior concha and the cribriform plate.
What are paranasal sinuses?
Paranasal sinuses are cavities within the skull bones
Where does the frontal sinus lie?
Within the anterior part of the frontal bone
Where do the ethmoid air cells lie?
Within the ethmoid bone (superior to the nasal cavity and medial to the orbits)
Where do the sphenoid sinuses lie?
Within the sphenoid bone
Where do the maxillary sinuses lie?
Within the maxillae of the facial skeleton
The maxillary sinuses lie lateral to the lateral walls of the nasal cavity
What does the frontal sinus drain into?
Middle meatus
What does the sphenoid sinus drain into?
Spheno-ethmoidal recess
What do the ethmoid air cells drain into?
Superior and middle meatuses
What does the maxillary sinus drain into?
Middle meatus
Where does the opening of the maxillary sinus into the middle meatus lie?
Superomedially, therefore it cannot drain freely when the head is upright