Lecture 14: An Overview and the Upper Respiratory Tract Flashcards
What is the role of the respiratory system?
to deliver warm, clean, moist air to the site of gas exchange
What are the key structures of the URT?
nose, nasal cavity, paranasal sinuses, pharynx
The whole of the respiratory tract is lined with
mucosa
What is mucosa?
A layer of epithelium attached via a basement membrane to underlying connective tissue (lamina propria)
What is the epithelium along most of the conduction region (nasal cavity, part of the pharynx, larynx, trachea, bronchi)?
Respiratory epithelium
What is the epithelium where food and air travel?
stratified squamous epithelium
What is the epithelium at the site of gas exchange?
simple squamous epithelium
What is the epithelium required for olfaction?
olfactory mucosa
What is olfaction?
Sense of smell
Describe respiratory epithelium
it is pseudostratified ciliated columnar epithelium with goblet cells
What is the role of the goblet cells?
to produce mucus
What is the role of mucus?
to trap debris and moisten air
What is the role of the cilia on the pseudostratified ciliated columnar epithelium?
to move the mucus that has caught the debris towards the pharynx so it can be swallowed and digested by the stomach acid
What is the nose made of and why?
Mainly cartilage so it is soft and flexible and to have a patent/unobstructed airway
What are the nostrils called?
external/anterior nares
What is the place called in your nose where you can stick your finger?
Vestibule
Describe the vestibule:
- what is it lined with
- is there hair? If so, what is it called?
- what gland(s) are there?
- skin
- yes (vibrassae)
- sweat and sebaceous glands
The roof of the nasal cavity is formed by what two bones?
ethmoid, sphenoid
What is the floor of the nasal cavity formed by?
hard and soft palates
What are the conchae?
three projections pushing into the nasal cavity
What are the conchae covered in?
respiratory epithelium
What is the role of the conchae?
swirl air to allow for more time to warm and moisten the air and for olfactory detection
Where is the olfactory cortex?
area on the roof of the nasal cavity
Why does the air need to be warmed?
To allow for more efficient gas exchange
How is the air warmed?
The lamina propria have veins which can dilate when it is cold to transfer heat to the air
What are the three regions of the pharynx?
nasopharynx
oropharynx
laryngopharynx
What is the pharynx?
Muscular funnel shaped tube shared by both the digestive and respiratory systems
What travels through the nasopharynx?
Because of this, what epithelium lines it?
air only
respiratory mucosa
Where is the nasopharynx?
posterior to the nasal cavity from the posterior nares to the soft palate
What is the role of the soft palate and the uvula in the nasopharynx during swallowing?
Prevent food from entering the nasal cavity
What is the role of the auditory tubes and where are they?
They drain here from the middle ear and they are in the nasopharynx
What travels through the oropharynx?
Because of this, what epithelium lines it?
air and food
stratified squamous epithelium for protection against abrasion
Where is the oropharynx?
posterior to the oral cavity from the soft palate to the hyoid bone
What travels through the laryngopharynx?
Because of this, what epithelium lines it?
air and food
stratified squamous epithelium for protection against abrasion
Where is the laryngopharynx?
from the hyoid bone to the beginning of the oesophagus
What are the paranasal sinuses
they are air filled cavities surrounding the nose.
Where are the paranasal sinuses found?
within the frontal, sphenoid, ethmoid and maxillary bones
What are the paranasal sinuses lined with?
respiratory mucosa
What are the 4 fuctions of the paranasal sinuses?
- lighten skull
- increased surface area to clean, warm and moisten the air
- sound resonance
- infected mucus can block drainage which means the sinuses are blocked
