1.2 wbk URT anatomy Flashcards
what does the URT comprise of ?
- nose & paranasal sinuses
- pharynx
- larynx
Which part of the respiratory tract is termed the URT ?
the part above the lower border of the cricoid cartilage (which forms the lower border of the larynx)
3 respiratory functions of the URT ?
- conducting air from atmosphere to LRT
- conditioning of inspired air (warming, humidification, trapping of particles)
- protection of the airway during swallowing (larynx)
functions of URT that aren’t respiratory related ?
- swallowing (oropharynx & laryngopharynx)
- smell (olfactory epithelium in nose)
- speech (larynx)
How is the nasal cavity divided ?
into R & L cavities by the median nasal septum
Each nasal cavity extends from the nostril or …1… in front to the posterior …2… / …3…. , behind, through which the nasal cavity communicates with the …4… situated behind it.
- anterior nares
- nares
- choanae
- nasopharynx
What does the lateral wall of each nasal cavity contain ?
3 bony projections known as conchae or turbinates
(superior, middle & inferior)
What i pace below each turbinate known as ?
meatus (superior, middle, inferior)
What opens into the meatus ?
paranasal sinuses and the naso-lacrimal duct which drains tears from the eye
the floor of the nasal cavity forms what ?
the roof of the mouth, which is the hard & soft palates
- how many paranasal sinuses exist ?
- how are they named ?
- what are the names ?
- 4
- for the skull bones within which they are situated
- frontal, ethmoidal, maxillary , spehnoidal
paranasal sinuses are ..1.. cavities in the skull that open into the …2… and are lined by ..3…
- air-containing
- nasal cavity
- respiratory epithelium
What role do the turbinates play in the nose?
increase the surface area for warming and humidification,
cause turbulence, and slow down airflow to increase the time available for these changes to occur.
How do the paranasal sinuses contribute to the function of the nose?
warming and humidification of inhaled air
What is the function of the coarse hairs lining the nostrils?
trap large particles in inhaled air
How is humidification of the air achieved in the nasal passage?
by transudation of fluid through the epithelium and to a lesser extent by mucus secretion
What role do goblet cells play in the nasal passage?
secrete mucus that traps almost all particles greater than 5 micrometres
What happens to the mucus and trapped particles in the nasal passage?
cilia waft the mucus to the oropharynx where it is swallowed
Why is nose breathing preferred over mouth breathing?
the nose always remains open, unlike the mouth, and it prevents the lower air passages from drying out and becoming more vulnerable to infection
What can happen to the lower air passages if nose breathing is impossible?
the lower air passages can dry out and become more vulnerable to infection
What is a potential consequence of mouth breathing during exercise, especially for asthmatics?
can lead to drying and cooling of the bronchial mucous membranes
which is thought to be a mechanism of bronchoconstriction in asthmatics.
How can infections of the upper respiratory tract spread from the nasal cavity? & where to does the spread happen ?
Via their respective openings
- paranasal sinuses
- pharynx
- larynx
- middle ear
- eye
what are the 3 parts that pharynx consists of ?
- nasopharynx
- oropharynx
- laryngo (hypo) pharynx
- where does the nasopharynx lie ?
- which part of pharynx ?
- behind the nose
- above the level of the soft palate
- where does the oropharynx lie ?
- which part of pharynx ?
- behind the mouth &
- between soft palate & tip of epiglottis
- where does laryngopharynx lie ?
- which part of pharynx ?
- behind the larynx
- between tip of epiglottis & lower border of the cricoid cartilage
what has a common passage through parts of the pharynx ?
air & food
Failure of mechanisms to prevent aspiration of food particles during swallowing can lead to / cause what ?
potentially life-threatening airway obstruction and/or infection (aspiration pnemuonia)
What does the eustachian tube allow ?
the air pressure in the middle ear cavity to be equalised to atmospheric pressure
Via what can URTI spread to middle ear cavity resulting in what ?
via auditory tube
resulting in = middle ear infection (acute otitis media)
What is the role of the vocal cords in respiration and swallowing?
act as a sphincter or valve, guarding the entrance to the trachea by being open during respiration and closed during swallowing
What risk is associated with dysfunctional vocal cords?
increase the risk of aspiration of food or liquid into the respiratory tract
Why is the ability to close the vocal cords necessary?
for an effective cough reflex, which is a protective mechanism to expel inhaled particles and clear excessive secretions from the airways
How can laryngeal disease present itself?
airway obstruction and difficulty in breathing
What can a voice change indicate in relation to serious intra-thoracic disease?
It can be the first sign of serious intra-thoracic disease due to the involvement of the left recurrent laryngeal nerve in the thorax
cartilaginous skeleton of the larynx is made up by what ?
- unpaired cartilages - the epiglottis, thyroid cartilage & cricoid cartilages
& - 1 set of paired cartilages - the arytenoid cartilages
what together is termed thhe glottis ?
the vocal cords + aperture between the cords
- Describe action of adduction of vocal cords
- this action results in what ?
- movement of vocal cords towards the midline
- closing the aperture e.g. during swallowing (glottis closed)
what results in the opening of the vocal cords aperture ? e.g during inspiration
Movements of the vocal cords away from the midline = abduction of the vocal cords
what happens to vocal cords during the following ?
1. swallowing
2. inspiration
3. speech (phonation)
4. initial part of the cough reflex
- adducted
- open
- partially open
- adducted
What muscles are the vocal cords moved by ?
small intrinsic laryngeal muscles
which muscles moves the entire larynx but not the vocal cords ?
extrinsic laryngeal muscles
which nerve supplies all intrinsic muscles except the cricothyroid muscle ?
recurrent laryngeal
Why can intra thoracic disease compressing / infiltrating the nerve result in a hoarse voice ?
paralysis of the left vocal cord
because the nerve on the left side has a long course , part of which is inside the thoracic cavity
Aspiration of food into the trachea is prevented by what ?
adduction of the vocal cords
what’s another mechanism to prevent aspiration apart from adduction of the vocal cords ?
epiglottis folds downwards to cover the laryngeal inlet
Difficulty in breathing can occure due to problems in the larynx causing narrowing / obstruction of the glottis including what ?
- laryngeal tumour or vocal cord tumours
- larygeal oedema
- bilateral vocal cord paralysis
laryngeal oedema can be due to what ?
- allergic reactions (e.g. anaphylaxis)
- severe infections (e.g. croup or acute epiglottitis)
Difficulty in breathing may also be due to problems in other parts of the URT other than problems in the larynx what could they be ?
- breathing problems in nose - polyps, tumours - results in mouth breathing
- problems in pharynx
