Lecture 17- The nose Flashcards
functions of the nose
- Smell and taste
- Breathing- route for inspired air
- Filters inspired air trapping particle sin nasal hair and mucous
- Moistens (humidifies) and warms
- Resonating chamber for speech
what is the external nose called
vestibule
anterior nares
nostrils/ nasal apertures
posterior nares
posterior nasal apertures (choanae)
external nose is made up of
cartilage (near the nostrils) and bones (at the top)
important bone of the nose
nasal bone (paired bone) found right at the top of the nose
- Clinical correlates of nasal bone
v
skin inside the vestibule
lined with skin containing sebaceous/sweat glands and hair–> filters inspired air
the nasal cavity has bony boundaires and is divided into left and right by the
midline spetum
features of the 2 lateral walls of the nasal cavity
- Irregular due to presence of bony projections (conchae/ turbinates)
- Superior (part of ethmoid)
- Middle (part of ethmoid)
- Inferior (other bone
what are the bony projections of the lateral walls reffered as
conchae or turbinates
turbinates create
meatues
- superior
- middle
- inferior
- Openings under the meatuses allows for drainage of the
- Paranasal air sinus in nasal cavity
- Nasolacrimal duct in nasal cavity
why do the lateral walls of the nasal cavity have this irregular anatomy?
- slows airflow by causing turbulence of airflow
- increases surface area over which air passes
roof of the nasal cavity
the roof of the nasal cavity is formed by nasal cartilages and several bones, chiefly the nasal and frontal bones, the cribriform plate of the ethmoid , and the body of the sphenoid.
epithelium of the respiratory part of the nose
lined by a ciliated psudeostratified epithelium, interspersed with mucus-secreting goblet cells.
Olfactory region of the nose –
located at the apex of the nasal cavity. It is lined by olfactory cells with olfactory receptors.
the roof of the nasal cavity can be used to
- to access parts of the brain found on the cranial floor
- Transsphenoidal surgical approach- e.g. gaining access to the pituitary gland via the sphenoid bone
floor of the nasal cavity
The floor, wider than the roof, is formed by the palatine process of the maxilla and the horizontal plate of the palatine bone, i.e., by the palate.
Medial wall of the nasal cavity-
The septum
The septum
- Consists of a bony and cartilaginous part
- Anterior= septal cartilage
- Posterior= perpendicular plate of the ethmoid bone and the vomer bone
clinical correlate- septa haematoma
- Potential complication from nasal injury
- Buckling(bending) of cartilage due to trauma
- Tears/shears blood vessel
- Accumulation of blood
- Strips perichondrium away from cartilage (nasal septum)
- Starving cartilage of blood supply
- Cartilage dies fibrosis and affects shape
- Infection can be an issue
diagnosis of septa haemtoma
- Diagnosis- must look up the nostrils for swelling
- septa haematoma treatment-
must be incised and drain and a tamponade placed to stick perichondrium back onto cartilage
But if you don’t treat septal haematoma-
Saddle nose deformity (equivalent tof cauliflower ear)
Saddle nose deformity
untreated septa haematoma leads to avascular necrosis of cartilaginous septum
- saddling of nasal dorsum (saddle-nose deformity)
ALWAYS EXAMINE FOR SEPTAL HAEMATOMAS IN PTS PRESENTING WITH NASAL INJURY
questionL while picking her nose, the queen accidently catchers her nail on the nasal mucosa. the pain is itnense causing her to wince. Which cranial nerve carriers genral sensation from the nasal cavity
- Trigeminal – Va/Vb- maxillary
Nerve innervation to the nose and nasal cavity
Trigeminal nerve (V)