Week 7- Structure and Function of the Airways

Question 1

What type of branching is found in the airways?

Answer 1

Dichotomus

Question 2

What gives airways mechanical stability?

Answer 2

Cartilage

Question 3

What do type I alveolar cells do?

Answer 3

Vey thin, they facilitate gas exchange

Question 4

What do type II alveolar cells do?

Answer 4

Replicate to replace type I cells
Secrete surfactant to reduce surface tension
Xenobiotic metabolism

Question 5

What are the main functions of the respiratory airways?

Answer 5

Get air efficiently to gas exchange region and keep the pipeway clear

Question 6

What are the 2 nasal passages?

Answer 6

Pharynx and conchae

Question 7

What is the role of the pharynx?

Answer 7

Passage for food, liquid and air

Question 8

What is the role of the conchae?

Answer 8

Contribute to warming and humidification of intra nasally inhaled hair

Question 9

In which nasal passageway are nose hairs found?

Answer 9

Conchae

Question 10

What are the 3 regions of the pharynx?

Answer 10

Nasopharynx
Oropharynx
Laryngopharynx

Question 11

What are the 3 main layers in the airway wall?

Answer 11

Mucus layer (topmost)
Cilia
Epithelial cells

Question 12

What cells are more prominent out of ciliated cells and goblet cells?

Answer 12

Ciliated cells

Question 13

What do serous cells secrete?

Answer 13

Anti bacterial enzymes

Question 14

Approx how many cilia are found on a ciliated cell?

Answer 14

200

Question 15

How do airway smooth muscle cells caliber the airway?

Answer 15

Via contraction or relaxation

Question 16

What do airway smooth muscle cells secrete?

Answer 16

Mediators
Cytokines
Chemokines

Question 17

When there is inflammation what do airway smooth muscle cells?

Answer 17

NO
Prostaglandins
Cytokines
Chemokines
Adhesion molecules

Question 18

What arteries supply the airways.

Answer 18

Bronchial

Question 19

How does blood return from tracheal circulation?

Answer 19

Via systemic veins

Question 20

How does blood return from bronchial circulation?

Answer 20

Via bronchial and pulmonary veins

Question 21

What nerves control airway function?

Answer 21

Parasympathetic (cholinergenic)

Sensory

Question 22

What regulatory and inflammatory mediators are involved in control of airway function?

Answer 22

Histamine
Arachidonic acid metabolites
Cytokines
Chemokines

Question 23

What do human airways lack that other animals have?

Answer 23

A sympathetic system to relax the airways

Question 24

What effect does acetylcholine have on the human airway?

Answer 24

Causes contraction of cells

Question 25

What are the main components of mucus?

Answer 25

Mucins, water, electrolytes

Question 26

What are some regulatory and inflammatory mediators that epithelium cells produce?

Answer 26

``` Nitric oxide Carbon monoxide Arachidonic acid metabolites Chemokines Cytokines ```

Question 27

How is nitric oxide produced by airway smooth muscle cells

Answer 27

Via NOS

Question 28

How are prostaglandins produced by airway smooth muscle cells?

Answer 28

Via COX

Question 29

What are some functions of the tracheo-bronchial circulation?

Answer 29

``` Good gas exchange Warming of air Humidification of air Clears inflammatory mediators Clears inhaled drugs ```

Question 30

What molecules relax the airway?

Answer 30

Nitric oxide (from NOS containing nerves) Adrenaline (from the adrenal gland) Sympathetic stimulation

Question 31

Define asthma

Answer 31

A clinical syndrome characterised by increased airway responsiveness to stimuli which leads to airway obstruction

Question 32

In asthma, what does airway inflammation lead to?

Answer 32

Re modelling

Question 33

In asthmatics what changes can be seen in the airway?

Answer 33

Thickening of the basement membrane Fragility of epithelial cells Mucus plug in the lumen (due to over activation of submucosal glands)

Question 34

What do respiratory disease like asthma, COPD and CF have in common?

Answer 34

All involve chronic inflammation that leads to airway remodelling

Question 35

What is the role of cilia?

Answer 35

To beat and allow mucociliary clearance