(PM3A) ENT - Nose Flashcards
Where are hairs in the nose that help to filter particles?
Nasal vestibule
What are the 3 bones in the nasal cavity?
Turbinates
(1) Superior turbinates
(2) Middle turbinates
(3) Inferior turbinates
What are the components of the nasal-associated lymphoid tissue?
(1) Tonsils
(2) Nasopharynx
Where is the respiratory mucosa?
On the turbinates (3 bones) in the nasal cavity
What sinuses are there in the nose?
(1) Frontal sinus (two of these)
(2) Sphenoid sinus
What is the cribriform plate?
Between the olfactory mucosa + olfactory bulb in brain
Bone-like structure
What are some of the key roles of the nose?
(1) Breathing
(2) Air-conditioning
(3) Filtration + purification
(4) Sinus ventilation
(5) Nasal resistance
(6) Vocal resonance
(7) Olfaction - smell
What is the role of the nose in breathing?
Nose is primary way to breathe
What is the role of the nose in air-conditioning?
Nasal mucosa adjusts temperature + humidity
Before entering lungs
What is the role of the nose in filtration and purification?
Hairs filter + trap
Mucous captures smaller particles
Swallow particles in nasopharynx
Secretions (IgA) to kill microorganisms
What is the role of the nose in sinus ventilation?
Sinuses make mucous to moisturise the nose
What is the role of the nose in nasal resistance?
Maintain positive pressure for respiratory system
What is the role of the nose in vocal resonance?
Chamber helps to produce different sounds
(m, n, ng)
What is the role of the nose in olfaction?
Olfactory neuroepithelium
Olfactory nerves and bulbs control olfaction (smell)
What is olfaction?
Smell
How does smell work? What is the mechanism?
(1) Detection of odour by olfactory receptor neurons in the olfactory epithelium
(2) Transmits signal through cribriform plate to mitral cells in the olfactory bulb in the brain
(3) Olfactory receptor neurons are supported by sustentacular cells (SuC) in olfactory epithelium
(4) Stem cells in olfactory epithelium can replace sustentacular cells and olfactory receptor neuron cells
How can sense of smell be affected?
Damaged/ loss of:
(1) Olfactory receptor neurons
(2) Sustentacular cells
(3) Mitral cells
Which cells in the nasal cavity are affected by SARS-CoV-2?
Sustentacular cells
What is anosmia?
Lack of smell
What is a sustentacular cell?
Supportive cells in the olfactory epithelium
Support olfactory receptor neurons
What are some of the drug targets delivered through the nose?
(1) Innervation from PNS
(2) Adrenergic receptors - dilation of nose vessels
(3) mAchRs - secretions
(4) Glucocorticoid receptors - inflammation
(5) Histamine H1 receptors/ mast cells - allergy
What are some of the key drugs classes to act on the nose?
(1) Decongestants - sympathomimetic amines
(2) Decongestants - sodium chloride solution 0.9%
(3) Anti-inflammatory glucocorticoid - beclometasone
(4) Suppressors of inflammatory mediator release
(5) Anti-histamines
(6) Anti-cholinergic (parasympatholytic)
What are some of the conditions that affect the nose?
(1) Rhinitis - allergic/ non-allergic
(2) Polyps
(3) Bacterial sinusitis
(4) Nasal staphylococci
(5) Nasal congestion
(6) Rhinorrhea
What is nasal congestion?
Blockage of the nasal cavity
Can be caused by:
- Rhinitis
- Polyps
- Infections (cold/ flu etc)
- Sinusitis
What is rhinorrhea?
Runny nose - excessive production of watery nasal mucous secretions by nasal mucosa
Can be caused by:
- Infections (cold/ flu etc)
- Cold temperature
- Rhinitis
What is allergic rhinitis?
Acute/ chronic inflammation of the nasal mucosa
Caused by allergens
How is inflammation caused in allergic rhinitis?
(1) IgE binds to allergens in the nasal cavity
(2) Leads to release of inflammatory mediators (histamine) from mast cells