The Respiratory System

Question 1

Where would you find a pancoast tumour?

What may happen if someone has a pancoast tumour?

Answer 1

In the apex of a lung.
Pressure on the C8 and T1 root of the brachial plexus, resulting in wasting of the small muscles of the hand and some pain and parasthesia of the forearm.

May also give rise to Horner’s syndrome due to pressure on the sympathetic trunk.

Question 2

What would cause a hoarse voice? (Think a type of cancer)

Answer 2

Cancer resulting in impingement on the left recurrent laryngeal nerve, which loops under the aorta.
An aneurysm of the aorta can also cause such hoarseness.

Question 3

Where would you find pseudostratified epithelium?

Answer 3

In the nasal cavity, pharynx, larynx, trachea, primary bronchi and secondary bronchi (with cilia and goblet cells)

Question 4

Where would you find simple columnar epithelium?

Answer 4

Bronchioles and terminal bronchioles (along with cilia and Clara cells BUT no goblet cells)

Question 5

Where would you find simple cuboidal epithelium (with clara cells and a few sparsely scattered cilia)?

Answer 5

Respiratory bronchioles

Alveolar ducts

Question 6

Where would you find simple squamous epithelia/type 1 (+ septal/type 2 cells)?

Answer 6

In the alveoli

Question 7

Where are the olofactory regions located?

Answer 7

In the superior posterior of each nasal fossa.

Question 8

What muscle would you find behind the trachea and in front of the oesophagus?

Answer 8

Trachealis muscle.

Question 9

What do secretions of the epithelium and submucosal glands of the trachea and bronchi contain?

Answer 9

Mucins, water, serum proteins, lysosome (destroy bacteria), antiproteases (inactive bacterial enzymes). Lymphocytes contribute immunoglobulins (esp IgA)

Question 10

In the trachea is the basement membrane unusually thick or thin?

Answer 10

Unusually thick (not sure why..)

Question 11

What does ‘respiratory epithelium’ describe?

A misonomer because gaseous exchange does not take place here

Answer 11

Pseudostratified ciliated epithelium

Which lines the majority of the upper respiratory tract.

Question 12

What happens to the below in COPD:
Goblet cells
Ciliated cells
Submucous glands

And what does this cause?

Answer 12

Hyperplasia of goblet cells (more cells)
Smaller proportion of ciliated cells
Hypertrophy of the submucous glands

Therefore more mucus and fewer cilia to move the mucous.
Result of a life time of smoking. Narrower airway.

Question 13

What does the pulmonary artery do?

Answer 13

Brings deoxygenated blood to the lungs.

Question 14

What does the pulmonary vein do?

Answer 14

Takes oxygenated blood to the heart

Question 15

What supplies the lungs with oxygenated blood?

Answer 15

The bronchial artery.

Question 16

True or false: A bronchiole contains cartilage

Answer 16

False.

A bronchioles contains no cartilage or glands.

Question 17

True or false: A bronchus contains cartilage and glands

Answer 17

True
Glands located in the submucosa
Cartilage reduced to small islands in the bronchus rather than whole circles in the primary bronchi

Question 18

How are the bronchioles held open

Answer 18

With alveoli.
In asthma the muscle layer contracts and closes down the lumen which is serious if you’re trying to get rid of air, you can suck air in however as you lower the pressure the bronchioles tend to collapse because the muscle is contracting around them.

Question 19

Where would you find a clara cell?

Answer 19

As bronchioles get smaller, goblet cells give way to clara cells, intersepted between ciliated cuboidal cells.

Question 20

What do clara cells do?

Answer 20

Clara cells secrete a surfactant lipoprotein which prevents the walls sticking together during expiration.

Question 21

How does epithelia change along the respiratory tract?

Answer 21

Initially pseudostratified –> simple columnar ciliated –> cuboidal

Question 22

What can measuring clara cell protein tell you?

Answer 22

If it is lowered then there is lung damage.

If it is increased in serum then there is leakage across the air-blood barrier.

Question 23

Why is it important we don’t have goblet cells in our bronchioles and further down?

Answer 23

To prevent individuals ‘drowning’ in their own mucus - not being able to cough it up and also prevents gaseous exchange.

Question 24

At what point in the respiratory tract do the passageways begin to open to alveoli?

Answer 24

Respiratory bronchioles (which lead on from terminal bronchioles)

Question 25

What can alveoli open on to?

Answer 25

A respiratory bronchiole
An alveolar duct
An alveolar sac
Another alveolus (via an alveolar pore)

Question 26

At what age do we stop developing alveoli?

Answer 26

Age 8

Question 27

What percentage of alveoli walls do type 1 cells make up?

Answer 27

90%.

Question 28

What shape are type II cuboidal cells and what percentage of surface area of the alveoli do they cover?

Answer 28

They are cuboidal (they produce surfactant) And they cover 10% of the surface area.

Question 29

What is emphysema?

Answer 29

Destruction of the alveolar walls and permanent enlargement of air spaces which can result from smoking or alpha 1-antitrypsin deficiency.

Question 30

What are the effects of emphysema?

Answer 30

Alveolar walls normally hold bronchioles open, allowing air to leave the lungs when exhaling.
When the walls are damaged bronchioles collapse making it difficult for air to empty. Air becomes trapped in the alveoli.
Hallmark sign: pursed lip breathing - keeps pressure high to keep bronchioles open.

Question 31

What is pneumonia?

Answer 31

Inflammation of the lung caused by bacteria.

The lung consolidates as the alveoli fill with inflammatory cells.