Respiratory System

Question 1

What is external respiration?

Answer 1

The exchange of gases between the body and environment - inhalation and exhalation cycle

Question 2

External respiration provides ________ which is input for energy production and metabolism

Answer 2

oxygen

Question 3

External respiration eliminates _________ - waste product of metabolism

Answer 3

carbon dioxide

Question 4

The blood transports oxygen and carbon dioxide between the ________ and ________

Answer 4

lungs

tissues

Question 5

The exchange of _______ and _________ between blood and tissues by diffusion is gradient dependent

Answer 5

oxygen and carbon dioxide

Question 6

Where are the lungs located?

Answer 6

In the pleural sac in the rib cage

Question 7

During inhalation, what happens to the diaphragm and intrapleural space?

Answer 7

Contraction of the diaphragm
Expansion of the interpleural space
Increase in negative pressure

Question 8

During exhalation, what happens to the diaphragm and the interpleural space?

Answer 8

Relaxation of the diaphragm
Decrease in the volume of the interpleural space
Increase of positive pressure

Question 9

What is the role of the conducting airways?

Answer 9

Allow air to enter/exit
Filter, warm and humidify inhaled air
Epithelium is composed of several cell types

Question 10

What is present on the trachea for protection and to keep it open?

Answer 10

Cartilage rings

Question 11

What is the role of the bronchi?

Answer 11

Produce mucus to trap dirt particles and microorganisms

Mucus is then continuously cleared by the cilia to the pharynx and swallowed

Question 12

In what group of people is cilia in the bronchi not functional?

Answer 12

Smokers

Question 13

Do bronchioles have cartilage rings?

Answer 13

No

Question 14

The pulmonary artery carries __________ blood

Answer 14

deoxygenated

Question 15

Bronchial circulation provides ___________ blood to larger airways

Answer 15

oxygenated

Question 16

What is the radius and thickness of an alveolus?

Answer 16

0.1mm radius and 0.2um wall thickness

Question 17

What is the role of the alveoli?

Answer 17

Primary site of gaseous exchange and passive diffusion

Question 18

The alveolar wall consists of a single layer of ___________ cells

Answer 18

epithelium

Question 19

The capillary wall consists of a single layer of ___________ cells

Answer 19

endothelial

Question 20

Erythrocytes contain _________ and ___________ anhydrase

Answer 20

haemoglobin carbonic anhydrase

Question 21

Carbonic anhydrase is important in the elimination of __________

Answer 21

carbon dioxide

Question 22

Carbon dioxide is mostly transported dissolved in the plasma as ______

Answer 22

HCO3-

Question 23

What are the 8 steps in gas exchange, starting with inhalation?

Answer 23

Inhalation - air from environment -> alveoli
Diffusion of oxygen from alveoli to lung capillary
Oxygen diffuses to RBCs and binds to haemoglobin
Systemic capillary - oxygen leaves haemoglobin and diffuses into tissue
CO2 goes from tissues to capillaries and is converted to HCO3- in erythrocytes
HCO3- travels in plasma to lungs where it is converted to CO2
CO2 diffuses across lung capillary wall into alveoli
Exhalation

Question 24

What are alveolar macrophages derived from?

Answer 24

circulating blood monocytes

Question 25

What are alveolar macrophages?

Answer 25

Phagocytic cells - provide defence against pathogens and inhaled drugs.

Question 26

Which cytokine do alveolar macrophages secrete?

Answer 26

Interleukin-1a

Question 27

In which two groups of patients is the efficiency of bacterial phagocytosis in the lungs reduced?

Answer 27

Smokers and COPD patients

Question 28

How does lysosomal trapping of drugs in alveolar macrophages take place?

Answer 28

Basic drugs and macrolides accumulate in the AMs, in particular in the lysosomes as they are acidic. Basic drugs become ionised and trapping takes place due to reduced ability of the protonated form of the drug to diffuse back into the cytosol.

Question 29

What does continuous drug accumulation in alveolar macrophages lead to?

Answer 29

Phospholipidosis - foamy AMs

Question 30

What is asthma?

Answer 30

Chronic inflammation of the airways causing contractibility of smooth muscles, reversible narrowing of airways

Question 31

What causes asthma?

Answer 31

``` Family history Eczema and allergy Second hand smoking Broncholitis Born prematurely Hormones ```

Question 32

What are the different ways in which asthma can be treated?

Answer 32

Long-term treatment - inhaled corticosteroids, lukotriene modifiers, long acting beta agonists, combination inhalers Quick relief medication - short acting beta agonist, bronchodilators, corticosteriods, Allergy medications

Question 33

What are the effects of COPD?

Answer 33

Inflammed ariways, damaged air sacs, narrowing of airways, difficulty breathing

Question 34

What are the treatments options for COPD?

Answer 34

Stop smoking Diet - eat well to prevent weight loss and infections Exercise and pulmonary rehab Oxygen therapy, surgery Medication - Bronchodilator inhalers, steroid inhalers (reduce swelling)

Question 35

Pulmonary absorption as a means of drug absorption offers rapid access to __________ circulation due to large surface area of lungs, instantaneous absorption

Answer 35

systemic

Question 36

Does pulmonary absorption avoid first pass metabolism?

Answer 36

yes

Question 37

What is the disadvantage of pulmonary absorption?

Answer 37

only 2-10% of aerosol dose is deposited in lungs, 90% of dose is swallowed

Question 38

What are the three delivery systems for pulmonary drug administration?

Answer 38

Metered dose inhaler Dry powder inhaler Nebuliser

Question 39

How does a nebuliser work?

Answer 39

Atomisation of the liquid formulation into a mist of droplets for inhalation. It is used to give high doses of reliever medicine in severe asthma attacks

Question 40

How does a metered dose inhaler work?

Answer 40

Designed to deliver a specific dose of medicine. It releases aerosol of drug

Question 41

How does a dry powder inhaler work?

Answer 41

Delivers drug to lungs in dry powder particles. It relies on inhalation airflow to deliver drug