Respiratory System

Question 1

How do you locate the 2nd rib?

Answer 1

Find the sternal angle between the manubrium and the sternum - 2nd rib attaches at this point

Question 2

Why is the inferior aspect of each lung curved upwards?

Answer 2

This is because it lies on top of the domed diaphragm

Question 3

On a chest X-ray of a healthy individual, why is the domed diaphragm shown to be higher on the right?

Answer 3

This is on account of the liver

Question 4

In the respiratory system, what does the mucous membrane line?

Answer 4

The conducting portion of the respiratory tract, bearing mucus-secreting cells

Question 5

In the respiratory system, what do the serous membranes line?

Answer 5

The pleural sacs which envelop each lung

Question 6

In the balloon analogy, what does the outer balloon wall represent?

Answer 6

Parietal serosa

Question 7

In the balloon analogy, what does the inner balloon wall represent?

Answer 7

Visceral serosa

Question 8

What is in between the two pleural layers?

Answer 8

A thin layer of lubricating fluid

Question 9

What is the pleural cavity?

Answer 9

The space between the two layers

Question 10

What is it called when the pleural cavity fills with air?

Answer 10

Pneumothorax

Question 11

What is a haemothorax?

Answer 11

When the pleural cavity fills with blood

Question 12

What is it called when the pleural cavity fills with pus?

Answer 12

Empyema

Question 13

What is pleural effusion?

Answer 13

When the pleural cavity fills with a watery transudate or exudate

Question 14

In a PA view of a chest X-ray, which ribs are seen more clearly?

Answer 14

Posterior ribs

Question 15

How can fluid be drained from the pleural cavity?

Answer 15

Insertion of a wide-bore needle through an intercostal space - usually the 7th

Question 16

When fluid is drained from the pleural cavity, why is the needle inserted a fraction above the superior border of the lower rib?

Answer 16

To avoid the intercostal nerves and vessels which run along the inferior border of each rib

Question 17

When draining fluid from the pleural cavity, why shouldn’t the needle be inserted below the 7th intercostal space?

Answer 17

There is danger of penetrating the diaphragm

Question 18

When can lung cancer cause a paralysis of one side of the diaphragm?

Answer 18

If tumour impinges on the left or right phrenic nerve

Question 19

When can lung cancer cause wasting of muscles in the lower arm?

Answer 19

If tumour impinges on brachial plexus

Question 20

What is a Pancoast tumour?

Answer 20

Tumour of the pulmonary apex

Question 21

How is Horner’s Syndrome characterised?

Answer 21

Constricted pupils, weak droopy eyelids and apparent anhidrosis

Question 22

How is Horner’s Syndrome often caused?

Answer 22

Compression of nerves called the sympathetic trunk

Question 23

When can lung cancer result in a hoarse voice?

Answer 23

Impingement on the left recurrent laryngeal nerve, which loops under the aorta

Question 24

What is the conducting portion of the respiratory tract?

Answer 24

Nasal cavity to bronchioles

Question 25

What is the respiratory portion of the respiratory tract?

Answer 25

Respiratory bronchioles to alveoli

Question 26

What happens to the walls of the passageways as their lumens decrease in diameter?

Answer 26

Their walls become thinner

Question 27

How does the epithelia change in the respiratory tract?

Answer 27

Psuedostratified epithelia with cilia and goblet cells lines the airways from the nasal cavity to largest bronchioles Simple columnar epithelia with cilia and Clara cells but no goblet cells line smaller bronchioles and terminal bronicholes of conducting portion Simple cuboidal epithelia with Clara cells line respiratory bronchioles and alveolar ducts Simple squamous epithelia line alveoli

Question 28

What allows for the detection of odours?

Answer 28

Olfactory mucosa

Question 29

Why do venous plexuses swell every 20-30 minutes?

Answer 29

Alternates air flow from side to side to prevent overdrying and warm inspired air

Question 30

How is patency maintained?

Answer 30

Surrounding cartilage or bone

Question 31

Which type of epithelium lines the olfactory region?

Answer 31

Pseudostratified epithelium

Question 32

What do Bowman's glands in the olfactory region do?

Answer 32

Flush odorants from the epithelial surface

Question 33

What are the ventricular folds of the larynx lined by and what do they contain?

Answer 33

Pseudostratified epithelium and they contain ucous glands and numerous lymph nodules

Question 34

Which type of epithelium is each vocal chord of the larynx lined by and what do they contain?

Answer 34

Stratified squamous epithelium - contains a vocal ligament and a vocalis muscle

Question 35

What happens to the vocal chords when coughing is required?

Answer 35

They close to build up pressure

Question 36

How long and wide is the trachea?

Answer 36

10cm long, 2.5cm wide

Question 37

In the wall of the trachea, which layer is thicker in patients with COPD?

Answer 37

Submucosa

Question 38

In COPD, what happens to the proportion of mucus to cilia?

Answer 38

Hyperplasia of goblet cells means more mucous is produced but a smaller proportion of ciliated cells so there is more mucous and fewer cilia to move the mucous

Question 39

In cystic fibrosis, what is the result of the lack of the CFTR ion channel?

Answer 39

Chloride ions cannot be transported across the membrane so water does not leave the epithelium in sufficient quantities to hydrate the secreted mucous. The mucous therefore becomes thick and viscous.

Question 40

Do bronchioles have cartilage or glands?

Answer 40

No

Question 41

What do pulmonary arteries carry?

Answer 41

Deoxygenated blood

Question 42

What is the diameter of a bronchiole?

Answer 42

1mm or less

Question 43

What keeps the lumen of bronchioles open?

Answer 43

Surrounding alveoli

Question 44

Why can absence of cartilage in bronchiole walls be problematic?

Answer 44

They can easily constrict when smooth muscle contraction becomes excessive

Question 45

What becomes excessive in asthma?

Answer 45

Bronchoconstriction

Question 46

What are Clara cells now known as?

Answer 46

Club cells

Question 47

What do Club cells (Clara cells) secrete?

Answer 47

Surfactant lipoprotein which prevents the walls sticking together during expiration as well as 'Clara cell protein'

Question 48

Why are goblet cells absent in terminal bronchioles?

Answer 48

To prevent individuals 'drowning' in their own muscous

Question 49

Up to what age do new alveoli continue to develop?

Answer 49

8 years - when there are approximately 300 million

Question 50

What do alveoli walls consist of?

Answer 50

Abundant capillaries, supported by basketwork of elastic and reticular fibres, covering of type I pneumocytes and a scattering of intervening type II pneumocytes

Question 51

How close does air in alveoli lie from blood streaming through capillaries?

Answer 51

0.2 micrometres

Question 52

What are type I cells in alveoli?

Answer 52

Squamous

Question 53

What are type II cells in alveoli?

Answer 53

Cuboidal

Question 54

What is emphysema caused by?

Answer 54

Destruction of alveolar walls and permanent enlargement of air spaces. It is difficult for the lungs to empty

Question 55

What is a distinctive sign of emphysema?

Answer 55

Pursed-lip breathing

Question 56

What is pneumonia caused by?

Answer 56

Inflammation of the lung caused by bacteria. The lung consolidates as the alveoli fill with inflammatory cells

Question 57

What does the parietal pleura line?

Answer 57

Chest wall

Question 58

What does the visceral pleura cover?

Answer 58

The lung

Question 59

Why are the two membranes separated by lubricating pleural fluid?

Answer 59

Fluid reduces friction, allowing the pleura to slide easily during breathing and provides the surfact tension to prevent the lung recoiling and collapsing

Question 60

What is the normal pleural fluid quantity?

Answer 60

Approximately 25ml per lung

Question 61

During inspiration, what is the approximate intrapleural pressure?

Answer 61

-8cmH20 (below atmosphere)

Question 62

During exhalation, what is the approximate intrapleural pressure?

Answer 62

-4cmH20 (below atmospheric)

Question 63

What does Boyle's law state?

Answer 63

When the volume of a container increases, the pressure decreases

Question 64

What is intrapleural pressure?

Answer 64

Pressure within the pleural cavity

Question 65

What is intrapulmonary pressure?

Answer 65

Pressure within the lung

Question 66

What does the pressure difference of 4cmH20 across the alveolar wall do?

Answer 66

It is the force that keeps the stretched lungs adherent to the chest wall

Question 67

What happens when air enters the pleural space?

Answer 67

The -4cmH20 pressure gradient that normally keeps the lungs against the chest wall disappears so the lung recoils and collapses

Question 68

What does LaPlace's law state?

Answer 68

The larger the vessel radius, the larger the wall tension required to withstand a given internal fluid pressure

Question 69

What is the role of surfactant?

Answer 69

During inspiration, surfactant molecules move apart. During expiration, surfactant molecules move together so surface tension is reduced

Question 70

What does surfactant deficiency lead to?

Answer 70

Stiff lungs that are very difficult to ventilate