Lecture 3: Upper airways

Question 1

Describe the epithelium of the nares//conchae:

Answer 1

3 Conchae (turbinet bones)

Resp epithelium

• Ciliated
• Goblet cells

Question 2

Describe the epithelium of the pharynx:

Answer 2

• Some stratified epi b/c food (3 divisions) and resp epithelium

Question 3

What is the function of the respiratory epithelium?

Answer 3

1. Clean (Filter)
2. Humidified
3. Warm

Question 4

What are the anatomical divisions of the respiratory system?

Answer 4

Upper airways: Nasal cavity, pharynx, larynx

Lower airways: Trachea, bronchi, bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli

Question 5

What are the functional divisions of the respiratory system?

Answer 5

Conduction zone: Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

Respiratory zone: Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli

Question 6

How many times does the bronchiole tree divide before the resp. zone?

Answer 6

~17 times, suggested to be clinically important

Question 7

What are the cells of the respiratory tract?

Answer 7

Psuedostratified columnar ciliated epithelium
Goblet cells
Club (clara) cells
Type 1 pneumocytes (At1)
Type 2 pneumocytes (AT2)
Macrophages

Question 8

Write some notes on pseudostratified columnar ciliated epithelium location and function:

Answer 8

Located: Conducting Zone: Nasal cavity, nasopharynx, trachea, bronchi (large)

Function: Ciliated-> Movement of mucous, motile cilia

Question 9

Write some notes on goblet cells location and function

Answer 9

Location: Most of conducting zone; Nasal cavity, nasopharynx, trachea, bronchi (large)

Function: Mucous, not ciliated

Question 10

Write some notes on club cells location and function;

Answer 10

Location: Bronchioles, cuboidal ciliated epithelium too

Function: Provides liquid lining (finer mucous), secrete watery substance -> Antimicrobial properties

Question 11

Write some notes on type 1 pneumocytes location and function:

Answer 11

Location: Respiratory zone

Function: Squamous, (like egg), thin air-blood barrier

Question 12

Write some notes on type 2 pneumocytes location and function:

Answer 12

Location: Respiratory zone, secrete surfactant

Question 13

Write some notes on alveolar macrophage location and function:

Answer 13

Location: Alveoli

Function: Defence, wandering- can move between b/w alveoli

Question 14

Whats the connective tissue of the respiratory system?

Answer 14

Cartilage
Elastic fibres
Collagen
Smooth muscle

Question 15

Where is cartilage found in the respiratory tract and whats its function?

Answer 15

Found: Trachea and bronchi

Function: Airways open

Question 16

Describe elastic fibres location and function in the respiratory tract?

Answer 16

Found: Everywhere

Function: Ventilation - Impacted by COPD (Obstruction_

Question 17

Describe collagen fibres location and function:

Answer 17

Location: Everywhere

Function: Support + Diaphragm (restrictive i.e CF)

Question 18

Where is SM found in the Respiratory tract and what is its function?

Answer 18

Found: Trachea to the alveolar ducts

Function: Most important site is bronchioles, controls airflow

Question 19

What are the two sources of mucous in the respiratory tract?

Answer 19

1. Goblet cells

2. Seromucous glands

Question 20

Where are seromucous glands found and what are their function?

Answer 20

Seromucous glands are found in the submucosa of the nasal cavity, trachea, bronchi

Question 21

Describe the mucous layer of the airways?

Answer 21

Biphasic
- Serous watery (Sol layer) in which cilia beat
and
- Visoeleastic or gel layer, above

(mucociliary escalator)

Question 22

What other liquid layers are in the respiratory tract?

Answer 22

Bronchiole and respiratory zone airway secretions are compromised of club cell secretions and surfactant.

Question 23

Whats the overall function of the conducting zone?

Answer 23

1. To prepare the air for gas exchange

2. To get air into the respiratory zone as efficiently as possible

Question 24

What happens to mucous with smoking?

Answer 24

Smoking kills of motile cilia therefore theres thicker mucous (gel layer)