Respiratory tract Flashcards
Function of respiratory tract
respiration (gas exchange). Conducts, warms and humidifies air and protects against pathogens
What 2 components make up the respiratory tract?
Upper and lower respiratory tract
Which components make up the upper respiratory tract?
nose, paranasal sinuses, mouth (inc tonsils), pharynx, larynx
What forms the protuberance of the nose?
nares (nostrils)
What forms the nasal septum?
Vomer bone (and bit of ethmoid) and hyaline cartilage
What tissues make up the nose?
skin, muscle, bone, hyaline cartilage (where nasal septum is found)
Where is muscle found in the nose?
in the corner of the nose (for flaring)
What is the internal portion of the nose referred to?
nasal cavity
Where is the nasal cavity located?
superior and posterior to the nose, inferior to the anterior cranial fossa, superior to the mouth
Which other aspects of the respiratory tract is the nasal cavity continuous with?
nares (external nose) and pharynx
Which ducts open up in the nasal cavity?
ducts from the paranasal sinuses and the nasolacrimal duct
Where does the nasolacrimal duct run from and to?
from the medial canthus of the eye (corner) to the inferior nasal meatus
What is the inferior nasal meatus?
A small space beneath the inferior nasal concha where the nasolacrimal duct opens up
Which gland produces tears?
Lacrimal gland
How do tears pass from the eye to the nose?
Via the nasolacrimal gland which connects the medial canthus of the eye to the inferior nasal meatus
What epithelium makes up the external portion of the nose?
Stratified squamous keratinised epithelium (with hairs)
What are the two segments of epithelium within the nose?
Respiratory and olfactory segments/epithelium
What epithelium is found in the nose (making up the respiratory and olfactory segments)?
ciliated pseudostratified columnar epithelium
What is the difference between the olfactory and respiratory segments in the nose?
The olfactory segment has olfactory receptors
Where is the olfactory epithelium/segment located?
At the roof of the nasal cavity, superior and posterior to the nose
Function of the olfactory segment/epithelium
detect airborne odour molecules (smell)
How do we detect smell?
Airborne odour molecules enter the nasal cavity and bind to olfactory receptors. The receptors are activated and send an impulse via the olfactory nerve (CNI) to the olfactory system.
What forms the first line of defence to prevent particles entering further into the nose?
nasal hairs found near nares
What are the functions of the nose?
Warms and filters the air (via conchae/turbinates) and sense of smell