Nose/Sinuses Anatomy/Physiology Flashcards
What are the functions of the nose?
To warm and humidify air through the turbinates, septum and mucosal lining.
To act as an immune barrier through the specialised nasal mucosa that has hair and cilia. The mucous produced contains IgA, IgE and lysozymes in an alkaline environment. It has a gel layer (thick) and a sol layer (watery).
It allows the sense of smell through the olfactory nerve fibres coming in from the cribriform plate to the olfactory epithelium.
It drains and aerates the middle ear through the Eustachian tube.
It drains the paranasal sinuses and the lacrimal duct.
What is choanal atresia?
It is a congenital disorder in which the nasal fossae are not recanalized during development due to abnormal growth of bony or membranous tissue. This causes neonates (who breathe solely through their nose) to go blue and start crying, they then can breathe when crying but are stuck in a cycle. Requires surgery to reopen nasal passages.
What are the functions of the sinuses?
Lighten the skull Reservoir of warm air Crumple zones to protect brain Act as immune barrier Add vocal resonance to voice
What bones make up the bony part of the nose?
Nasal bones and maxilla
What are the borders of the internal nose?
Roof-skullbase/cribriform plate
Walls-turbinates
Floor-hard palate
What bones and cartilage make up the septum?
Perpendicular plate of ethmoid
Septal cartilage
Vomer
What is a septal haematoma?
Caused by poor supply to the septal cartilage from drugs (vasoconstrictors-cocaine) or trauma. Is usually bilateral and can lead to perforation of the septum.
What are turbinates?
Bony projections from lateral wall of nose to increase surface area. They have erectile tissue covering them for air humidification. Each has a meatus under it. Sinus openings and nasolacrimal duct lie beneath.
What is the nasolacrimal duct and beneath which turbinate does it open?
It is a drainage pathway for lacrimal secretions from the lacrimal sacs beside the eye. It opens under the inferior turbinate (meatus).
Where is the frontal sinus and where does it drain into?
It is behind the eyebrow and it drains into the frontal recess via the middle meatus lateral the middle turbinate.
What is the ground lamella?
When the middle turbinate folds back on itself to attach to the nasal wall.
Where do the ethmoid sinuses lie and where do they drain into?
Anterior ethmoids lie anterior to the ground lamella and they drain into the inferior meatus. Posterior ethmoids lie posterior to the ground lamella and they drain into the superior meatus.
Where does the sphenoid sinus drain into and what are some important surrounding structures?
Drains into the sphenoethmoidal recess. Optic nerve runs above it and carotid lateral.
Where do the maxillary sinuses drain?
They drain into the middle meatus.
How is chronic sinusitis managed?
Remove any triggers
Give antibiotics
Give steroids
Do surgery to remove polyps or open up nasal passage
