Respiratory System Histology Flashcards
What are the functions of the respiratory system?
* Supplies oxygen to the blood for delivery to cells throughout the body
* Removes carbon dioxide that has been accumulated in the blood from body tissues
* Phonation (speech)
* Olfaction (smell)
* Lungs function in blood pressure control via renin-angiotensin system
What is the function of the renin-angiotensin system in the lungs?
Control of blood pressure
Explain the process of the renin-angiotensin system in the lungs
Angiotensin I is converted to angiotensin II via angiotensin-converting enzyme (ACE) in the lung capillaries
Explain the flow of air through the lungs
* Air enters the nose or mouth
* Travels via the pharynx and larynx into the trachea
* Trachea branches into the principal bronchi to convey the air to the lungs
* In the lung, each bronchus divides into smaller bronchi which divide into smaller bronchioles
* These bronchioles terminate in the alveolar sacs where gas exchange occurs
What are the functions of the nasal cavity?
* Warming inspired air
* Moistening inspired air
* Filtering inspired air
What cell types are present on the roof of the nasal cavity?
Olfactory epithelium
What is the initial part of the nasal cavity called?
The vestibule
What cell type is the vestibule lined with?
Keratinised stratified squamous epithelium
What is the rest of the nasal cavity (excluding vestibule) lined with?
Respiratory epithelium - pseudostratified, ciliated, columnar epithelium with goblet cells
What cells line the conducting part of the respiratory system?
Respiratory epithelium - pseudostratified, ciliated, columnar epithelium with goblet cells
Name the structures labelled 1-5
1) Pseudostratified, ciliated, columnar epithelium with goblet cells 2) Goblet cell 3) Basal cell (stem cell) 4) Cilia 5) Lamina propria/submucosa
What is the purpose of cilia?
Clearance of mucous
What is the purpose of goblet cells?
Production of mucous
Which areas of the respiratory tract have respiratory epithelium?
* Nasal cavity
* Nasopharynx
* Conducting airways
Which areas of the respiratory tract have stratified squamous epithelium?
* Vestibule
* Oropharynx
* Laryngopharynx
Where are olfactory epithelium located?
Olfactory mucosa
What lies beneath the respiratory epithelium?
Lamina propria
What is the lamina propria?
A band of connective tissue containing seromucous glands and a rich venous plexus
What happens to the venous plexus in the lamina proper in an allergic reaction?
Release of histamine causes the blood vessels to become engorged which āblocksā the nose
What cell type lines the oropharynx?
Non-keratinsed, stratified, squamous epithelium
What cell type lines the posterior surface of the epiglottis?
Non-keratinsed, stratified, squamous epithelium
Why is the oropharynx lined with non-keratinsed, stratified, squamous epithelium?
The oropharynx transmits both air and swallowed food - it must resist abrasion
What cell type lines the larynx?
Respiratory epithelium
What cell type is the anterior surface of the epiglottis lined with?
Respiratory epithelium
Which areas of the larynx are not covered with respiratory epithelium?
Vocal folds and adjacent structures
What are vocal folds and adjacent structures lined with?
Stratified squamous epithelium
Why are vocal folds lined with stratified squamous epithelium rather than respiratory epithelium?
Respiratory epithelium would be damaged by vocal folds rubbing together
What does trachea terminate into?
Right and left main bronchi
How many tracheal rings are there?
Trachea contains 15-20 āCā shaped cartilages
What lines the open side of the āCā of the cartilage?
* Fibroelastic tissue * Smooth muscle
What are tracheal rings composed of?
Hyaline cartilage