Introduction

Question 1

What are the 5 functions of the respiratory system?

Answer 1

Gas exchange
Regulation of body pH
Protection
Vocalisation
Synthesis of hormones

Question 2

Where does gas exchange occur in the body?

Answer 2

Between the atmosphere and blood

Between the blood and tissue

Question 3

Release of which molecule regulates body pH?

Answer 3

CO2

Question 4

How does CO2 regulate body pH?

Answer 4

CO2 + H2O –> H2CO3
H2CO3 –> H+ + HCO3-
H+ release which can change pH levels

Question 5

Why is the respiratory system needed for vocalisation?

Answer 5

Air flow is needed through he vocal chords to make a sound

Question 6

What enzyme is synthesised in the lungs?

Answer 6

Angiotensin

Question 7

What is external respiration?

Answer 7

Exchange between the atmosphere and the lungs
Gas exchange in the lung
Transport of O2/CO2 in the bloodstream
Gas exchange in the tissue

Question 8

What is cellular respiration?

Answer 8

Chemical reactions in cells producing ATP using O2

Question 9

What makes up the upper respiratory tract?

Answer 9

Nasal cavity, pharynx, vocal cords, larynx

Question 10

What are the functions of the upper respiratory tract? (4)

Answer 10

The conchae warm and humidify air.
Hair cells and mucosal surfaces in the nose filter the air
Vocal cords and larynx used for vocalisation

Question 11

What makes up the lower respiratory tract?

Answer 11

Trachea
Bronchi
Bronchioles
Alveoli

Question 12

What are the functions of the lower respiratory tract? (4)

Answer 12

Conduct air
Stabilise conductive airways
Regulate flow
Gas exchange

Question 13

What are the conductive airways?

Answer 13

The airways that conduct clean, warm, moist air
Nose, pharynx, larynx, trachea, bronchi, bronchioles.
No gas exchange occurs here

Question 14

Describe the structure of the trachea and what is the purpose of this?

Answer 14

Supported by U-shaped cartilage rings, they help to protect the trachea against insult from outside and ensure it doesn’t collapse as a result of airflow through it.
Not a full ring so can expand when something large passes through it.

Question 15

When are the muscles around the trachea used?

Answer 15

When coughing

Question 16

How is the upper part of the bronchi held open?

Answer 16

Cartilage rings

Question 17

How is the lower part of the bronchi held open?

Answer 17

Plates

Question 18

Does the bronchi have a muscular layer?

Answer 18

No

Question 19

What cells are found int he epithelium of the conducting airways? What is the name of this system?

Answer 19

Goblet cells and ciliated cells

Mucocillary escalator

Question 20

What is the function of goblet cells?

Answer 20

Secrete mucous to form a continuous protective layer over the surface of the respiratory tract

Question 21

What is the function of the ciliated cells?

Answer 21

Sweeps mucous upwards towards the pharynx

Question 22

What is the function of the mucocillary escalator?

Answer 22

Removes noxious particles from the lungs

Question 23

Do the bronchioles have cartilage rings? What does this mean?

Answer 23

No

They can collapse and become obstructed

Question 24

What type of muscle lines the walls of the bronchioles?

Answer 24

Smooth muscle cells

Question 25

How is the airway diameter of the bronchioles regulated? (4)

Answer 25

``` Gas composition (CO2) Hormones (histamine constricts the bronchioles) Parasympathetic NS (Ach acts on M3 receptors on smooth muscle cells to cause bronchoconstriction) Sympathetic NS (NA acts on beta 2 receptors on smooth muscle cells to cause bronchodilation) ```

Question 26

What is the difference between the structure of the side of the alveoli facing the capillaries and the supporting side?

Answer 26

The side facing the capillaries is delicate and leaky to allow gas exchange The supporting side is rich in collagen IV, it is robust and contains elastic fibres

Question 27

What property of alveoli is essential to the function?

Answer 27

The elastic properties

Question 28

Does the pulmonary artery conduct oxygenated or deoxygenated blood?

Answer 28

Deoxygenated

Question 29

What is the purpose of the extensive capillary network?

Answer 29

Provide a large SA for gas exchange

Question 30

What is shunt?

Answer 30

Blood from the bronchiolar artery draining directly into the pulmonary circulation to reduce O saturation

Question 31

What are the 2 types of alveolar cells and their functions?

Answer 31

Alveolar cell type I --> gas exchange | Alveolar cell type II --> secrete surfactant which reduces surface tension and stops the alveoli from collapsing

Question 32

What is the purpose of macrophages in the alveoli

Answer 32

They protect the alveoli from small particles and ingest degraded surfactant

Question 33

What is the purpose of pores of Kohn?

Answer 33

Intra-alveolar ventilation

Question 34

How are flow and resistance related?

Answer 34

Flow is inversely proportional to resistance

Question 35

Why do the bronchioles have the highest resistance?

Answer 35

They have the smaller diameter

Question 36

What does resistance depend upon? (3)

Answer 36

Diameter of the airways Flow pattern (laminar or turbulent) Viscosity of the gas

Question 37

Why does resistance increase in inflamed airways or in airways with increased mucous production?

Answer 37

In both circumstances the diameter of the airway decreased