Respiratory Anatomy 2 - Lower Respiratory Tract

Question 1

This component of respiratory system preps the air for gas exchange, helps with olfaction and resonance of sound

Answer 1

Upper respiratory system

Question 2

What are the 3 main types of epithelium found in the upper respiratory system?

Answer 2

Stratified squamous epithelium, olfactory epithelium, respiratory epithelium

Question 3

What are the 5 key components of the lower respiratory system?

Answer 3

Larynx, trachea, bronchi, bronchioles, alveoli

Question 4

What are the 3 main functions of the LRT?

Answer 4

1) gas exchange (conducts air to/from sites of gas exchange)
2) completes cleaning, warming, and humidifying of air
3) provides blood-air barrier and large SA for gas exchange

Question 5

This allows the passage of air only. It lies anterior to the esophagus. (Main airway)

Answer 5

Larynx

Question 6

What is the role of cartilage in the larynx?

Answer 6

It protects and maintains an open airway

Question 7

This closes over the airway when swallowing.

Answer 7

Epiglottis

Question 8

This is known as the ‘true’ vocal cord. The passing air causes vibrations which results in sound waves; it is used for normal phoation.

Answer 8

Vocal folds

Question 9

These are known as the ‘false’ vocal cords. It is superior to the vocal folds and prevent foreign object entry into the glottis

Answer 9

Vestibular folds

Question 10

This affects cartilage and muscle in the vocal folds which results in longer and thicker folds, and thus a deeper voice.

Answer 10

Testosterone

Question 11

This can produce very deep sounds.

Answer 11

Vestibular folds

Question 12

This maintains the patent airway (keeps it open and obstruction free). It is anterior to the esophagus and sits between the larynx and the primary bronchi

Answer 12

Trachea

Question 13

What is the trachea made of? (2 components)

Answer 13

C-shaped cartilage rings, elastin fibres in lamina propria + submucosa

Question 14

What type of epithelium lines the trachea?

Answer 14

Respiratory epithelium

Question 15

This has structures known as cilia that move the debris to the pharynx to be swallowed and digested. Mucus and mucosal glands line the surface of the epithelium.

Answer 15

Mucociliary escalator

Question 16

The ends of C-shaped cartilage rings are connected by a band of smooth muscle known as?

Answer 16

Trachealis

Question 17

Why is the cartilage of the trachea C-shaped?

Answer 17

To allow the esophagus to expand and stretch.

Helps to keep airways open and allows trachealis muscle to contract (to generate a cough)

Question 18

What is the function of the trachealis muscle?

Answer 18

Contracts and dilates (contracts to cough as well) but it helps the trachea to expand during swallowing, and constrict when not being used (to save space)

Question 19

This structure prevents food from entering the larynx (main airway)

Answer 19

Epiglottis

Question 20

What are the 2 folds of the larynx? What is their difference?

Answer 20

Vocal folds: passing air causes vibration (sound waves) ‘true’ vocal cords; used for normal phonation

Vestibular folds: prevent foreign object entry to the glottis; ‘false’ vocal cords; can produce deep sounds

Question 21

This is a part of the lungs where the bronchi and blood vessels enter.

Answer 21

Hilum

Question 22

How many lobes does the lungs have?

Answer 22

Right lung has 3 lobes
Left lung only has 2 lobes (because of the position of the heart)

Question 23

This is a dome-shaped structure that sits on top of the diaphragm.

Answer 23

Lungs

Question 24

The bronchial tree consists of what structures:

Answer 24

Trachea, primary, secondary and tertiary bronchi and terminal bronchioles

Question 25

How does the epithelium change throughout the bronchial tree?

Answer 25

Trachea - Respiratory epithelium
Primary bronchi - respiratory epithelium
Secondary and third bronchi - respiratory epithelium decrease in height - goblet cell numbers reduce
Bronchioles - cuboidal epithelium
Terminal bronchioles - no epithelium

Pattern: respiratory epithelium gets smaller, and the number of goblet cells decreases so less mucus is present as you go down the bronchial tree

Question 26

How does the structure of the cartilage change throughout the bronchial tree?

Answer 26

Trachea - C-shaped cartilage (to allow for constriction of dilation of trachea to accomodate food and also close when there’s no food present)

Primary bronchi - cartilage and smooth muscle rings are complete

Secondary and tertiary bronchi - cartilage plates

Bronchioles - no cartilage (only thick smooth muscle for bonchoconstriction and dilation)

Terminal bronchioles - no cartilage

Pattern: amount of cartilage decreases as you go down the bronchial tree. But amount of smooth muscle increases.

Question 27

Why is there no cartilage in the bronchioles?

Answer 27

Because there’s only smooth muscle to control bronchoconstriction/dilation

Question 28

These structures provide pulmonary lobules. This directs the air to the alveoli

Answer 28

Terminal bronchioles

Question 29

This zone is made of pulmonary lobules made of many alveoli (air sacs) arranged like bunches of grapes.

Answer 29

Respiratory zone

Question 30

Why are alveolar walls very thin? What kind of epithelium lines these walls?

Answer 30

Alveolar walls are lined with simple squamous epithelium on a thin basement membrane.

• it is thin to provide a greater surface area for gas exchange

Question 31

Approximately how much alveoli are in each lung?

Answer 31

150 million alveoli

Question 32

The external surface of alveoli is covered in a network of?

Answer 32

Pulmonary capillaries

Question 33

These are pocket-like structures covered by a dense capillary network meant for gas-exchange.

Answer 33

Alveoli

Question 34

This is the main type of epithelial cell found in the lungs/alveoli.

alveoli are found in the lungs

Answer 34

Pneumocytes

Question 35

This is a type of pneumocyte that forms the respiratory membrane/blood air barrier with capillary wall and shared basement membrane. Important for gas exchange .

Answer 35

Type 1 squamous pneumocytes

Question 36

This is a type of pneumocyte scattered amongst Type 1 squamous pneumocytes. They secrete surfactants.

Answer 36

Type 2 cuboidal pneumocytes

Question 37

This is a complex lipoprotein (phospholipid) that reduces the surface tension of the alveolar fluid.

Answer 37

Surfactant

Question 38

This removes the debris that makes it into the alveoli.

Answer 38

Macrophages

Question 39

This connects the alveoli to the bronchial tree/bronchii.

Answer 39

Alviolar duct

Question 40

What structures form the respiratory membrane?

Answer 40

Alveolar cell layer, fused basement membranes of alveolar and capillary epithelium, capillary endothelium + type 1 epithelial cells