Head/Neck--Nose,Paranasal Sinuses, Palate Flashcards
Nose
- the nose is an olfactory and respiratory organ
- it is divided into external and internal parts
External part of the nose (be able to label)
Composed of:
1) tip/apex
2) nostril/nares
3) root
4) dorsum (innervated by CN V1)
5) alar/winged lateral part
Which bones make up the nasal skeleton (be able to label)
- nasal
- frontal
- maxilla
The nasal skeleton (external) is made up of:
- bones
- cartilage (multiple, small, septal)
- dens fibrous CT (most lateral aspect of the nose)
Describe the functions of the nasal cavity
1) warms and humidifies the inspired air
2) removes and traps pathogens and particulate matter from inspired air
3) it is responsible for sense of smell
4) it drains and clears the paranasal sinuses and lacrimal duct
Internal part of the nose (be able to label)
- also referred to as the nasal cavity
- it is the most superior part of the respiratory tract
- it extends from the vestibule to the nasopharynx
- or from the nares (anterior nasal opening) to the choanae (posterior nasal opening)
Nasal vestibule
- it is the most anterior part of the nasal cavity
- it is initially lined by skin (keritanized) but as you go inward it transitions to typical respiratory epithelium before entering the nasal cavity
- small hairs called vibrissae that function to filter dust and other microscopic matter
What are the regions of the nasal cavity
- vestibule
- olfactory
- respiratory
Describe the olfactory region of the nasal cavity
It is located at the apex of the nasal cavity. It is lined by olfactory cells with olfactory receptors
Describe the respiratory region of the the nasal cavity
- it is the largest region and it is lined by ciliated pseudostratified epithelium
- within the epithelium are interspersed mucus-secreting goblet cells
Nasal septum
The medial wall of the nasal cavity
Which bones make up the nasal septum (be able to label them)
1) perpendicular plate of ethmoid (olfactory region)
2) vomer (posterior portion of nasal cavity)
3) maxilla (small contribution)
4) palatine (small contribution)
The anterior portion of the nasal septum is made of
-it is the septal cartilage made up of cartilage
Deviated septum
- occurs in 80% of all nasal septums
- common symptom from baldly deviated septum is difficulty breathing through the nose
- symptoms worse on one-side, can interfere with drainage of paranasal sinuses, resulting in repeated sinus infections
Lateral wall of the nasal cavity
- it is irregularly shaped compared to the smooth medial wall
- has 3 curved shelves of bones called conchae (turbinates)
1) inferior (largest/most anterior)
2) middle
3) superior (smallest/most posterior)
What are the functions of nasal conchae (turbinates)
- increase surface area of the nasal cavity to increase the amount of inspired air that can come into contact with the cavity walls
- disrupt fast laminar flow or air making it turbulent
- turbulent air spends longer time in nasal cavity so that it can be warmed and humidified
Nasal meatuses
- the air pathways created by concha projections
1) inferior meatus
2) middle meatus
3) superior meatus
Paranasal sinuses and superior/middle meatuses
-the paranasal sinuses drain into the nasal cavity using the superior and middle meatus
Nasolacrimal duct
- the nasolacrimal duct acts to drain tears from the eye
- it opens into the inferior meatus
- **hypertrophy of the inferior turbinate causes blockage of the inferior meatus and causes congestion