Nose

Question 1

Functions of the Nose

Answer 1

▪️olfaction- smell
▪️trap and remove particles
▪️adjust temperature and humidity of inspired air

Question 2

External nose

Answer 2

▪️frontal bone 
▪️frontal process of maxilla 
▪️nasal bone 
▪️septal cartilage- superior and lateral 
▪️major and minor alar cartilages

Question 3

Nasal cavity borders

Answer 3

▪️separated from oral cavity by hard palate
▪️separates from cranial cavity by frontal, sphenoid, ethmoid bones
▪️divided into two by nasal septum

Question 4

Nasal cavity regions

Answer 4

▪️nasal vestibule
-lines by skin and covers in hair follicles
▪️respiratory
-largest part
-rich neurovascular supply-warm air up
-lined by ciliated and mucous cells -trap particles
▪️olfactory
-olfactory receptors sense different smells

Question 5

Nasal cavity lateral walls

Answer 5

▪️conchae- curbed shelves of bone 
-spheno-ethmodial recess 
-superior conchae
-superior nasal meatus 
-middle conchae
-middle nasal meatus 
▪️increases SA so more contact to warm up inspired air 
-inferior conchae 
-inferior nasal meatus

Question 6

Paranasal sinuses

Answer 6

▪️lined by respiratory mucosa-cilliated and mucus secreting
▪️open into nasal cavities to allow drainage
-lightens the skull, resonance (project voice), absorbing shock when hit
▪️frontal, sphenoidal, ethmoidal, maxillary

Question 7

Paranasal sinus drainage

Answer 7

▪️fills up with mucous and can be drained by blowing nose which decrease pressure in nasal cavity drawing the mucous out of sinuses
▪️frontal and anterior ethmoidal- infundibulum/meddle meatus
▪️middle ethmoidal-bulla ethmoidalis/middle meatus
▪️posterior ethmoidal-superior meatus
▪️sphenoidal-spheno-ethmoidal recess
▪️maxillary- hiatus semilunaris

Question 8

Blood supply of the nose

Answer 8

▪️anterior and posterior ethmoidal arteries -ophthalmic (V1)
▪️lateral nasal branches- facial
▪️sphenopalatine- maxillary
- kiesselbach’s area- where arteries anastomose(come together to supply same area)
-common site of epitaxis (nose bleeds scratching)

Question 9

Olfactory nerve

Answer 9

▪️CNI

• nerve fibres (inside nasal cavity)
• bulb (on top of cribiform plate -sieve like)
• tract (splits into medial and lateral stria)
• medial stria- connects to other side
• lateral stria- goes to temporal lobe to primary olfactory cortex

Question 10

Anosmia

Answer 10

-no sense of smell
▪️temporary 
-infection- meningitis
-common cold- blocked nose 
▪️permanent
-head injury 
-tumour 
▪️progressive 
-neurodegenerative conditions- Alzheimer’s

Question 11

Innervation of nasal cavity and sinuses

Answer 11

▪️trigeminal nerve V