Lecture topic 16: Anatomy of the respiratory tract

What is olfaction? (simple terms)

Smell

What is the structural organisation of the upper respiratory tract composed of?

Nose / pharynx / paranasal sinuses / larynx

What is the structural organisation of the lower respiratory tract composed of?

Trachea / bronchi / bronchioles / alveoli

What are all the functions of the upper respiratory track?

Warm & moisten & filters air / olfaction / resonates sound

What are the functions of the NOSE?

Warm, moisten & filters air / receptors for smell / modify speech sound

State all the functional adaptions of the nose

Vibrissae / conchae / mucosa / rich capillary / olfactory mucosa / paranasal sinuses

What are vibrissae?

Hairs at entrance to nose which trap large dust particles

What does the conchae do?

Produce turbulence which allows more time to warm and moisten air

What is the structure of conchae?

Shelf like projections from lateral wall

What type of cells make up the mucosa?

Pseudostratified ciliated columnar epithelium with goblet cells

What is the function of the mucosa?

Produce mucous to trap particles which is waft in the pharynx by cilia

What is the importance of a rich capillary network underlining the mucosa?

Circulating blood warms the air

Where is the olfactory mucosa located?

In upper aspect of nose

What is the function for the olfactory mucosa?

Contain receptors for smell

What is the function for the paranasal sinuse?

Have air filled spaces that drain into nasal cavity / lighten the skull and resonate sound

State the 3 regions of the pharynx?

Nasopharynx / oropharynx / laryngopharynx

What is the red region?

Nasopharynx

What is the green region?

Oropharynx

What is the yellow region?

Laryngopharynx

What is the anatomical location of the nasopharynx to the nose?

Posterior to nose

What is the laryngopharynx posterior to?

The larynx

What does the pharynx do?

Forms a communal passageway for respiratory and gastrointestinal systems

What are the main functions of the larynx?

Maintain open airway / prevent food entering lower respiratory tract / sound production

What are some additional functions of the larynx?

Coughing / defaecation

What does the larynx consist of?

Consist of a cartilaginous skeleton lined by membranes and moved by muscles

Epiglottis

Hyoid bone

Thyroid cartilage

Cricoid cartilage

What is the carina?

Where the trachea ends / bifurcates

How many / what shaped cartilages is the trachea composed of?

15-20 horseshoe

What is the function for the cartilages in the trachea?

Keep airway open

What does the trachealis muscles do?

Constrict during coughing

The cartilage in the trachea is horseshoe shaped, therefore does not fully connect. What joins the posterior ends of the cartilage?

Trachealis muscles

What type of cells lines the trachea?

Pseudostratified ciliated columnar epithelium

What type of cartilage are in primary bronchi?

C-shaped cartilages

What type of cartilages are in secondary bronchi?

Plates of cartilage

What type of cartilages are in tertiary bronchi?

Plates of cartilages

What type of cells line the bronchus?

Pseudostratified ciliated columnar epithelium with goblet cells

What type of cartilage are in bronchioles?

None

What are the bronchiole walls made up of?

Smooth muscles

What type of cells are in terminal bronchioles?

Simple columnar epithelium with cilia

What type of cells are in respiratory bronchioles?

Simple cuboidal epithelia

What type of cells do bronchioles have that produces surfactants?

Clara cells

What do clara cells do in bronchioles?

Produce surfactant

What are the alveolar ducts?

Elongated airways with walls made of alveoli

What type of epithelium are type I alveolar cells?

Simple squamous

What do type I alveolar cells do?

Forms wall of alveolus

What do type II alveolar cells do?

Secretes surfactant

What type of WBC are present in the alveolus?

Macrophage