The Respiratory System Flashcards
Where would you find a pancoast tumour?
What may happen if someone has a pancoast tumour?
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.
What would cause a hoarse voice? (Think a type of cancer)
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.
Where would you find pseudostratified epithelium?
In the nasal cavity, pharynx, larynx, trachea, primary bronchi and secondary bronchi (with cilia and goblet cells)
Where would you find simple columnar epithelium?
Bronchioles and terminal bronchioles (along with cilia and Clara cells BUT no goblet cells)
Where would you find simple cuboidal epithelium (with clara cells and a few sparsely scattered cilia)?
Respiratory bronchioles
Alveolar ducts
Where would you find simple squamous epithelia/type 1 (+ septal/type 2 cells)?
In the alveoli
Where are the olofactory regions located?
In the superior posterior of each nasal fossa.
What muscle would you find behind the trachea and in front of the oesophagus?
Trachealis muscle.
What do secretions of the epithelium and submucosal glands of the trachea and bronchi contain?
Mucins, water, serum proteins, lysosome (destroy bacteria), antiproteases (inactive bacterial enzymes). Lymphocytes contribute immunoglobulins (esp IgA)
In the trachea is the basement membrane unusually thick or thin?
Unusually thick (not sure why..)
What does ‘respiratory epithelium’ describe?
A misonomer because gaseous exchange does not take place here
Pseudostratified ciliated epithelium
Which lines the majority of the upper respiratory tract.
What happens to the below in COPD:
Goblet cells
Ciliated cells
Submucous glands
And what does this cause?
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.
What does the pulmonary artery do?
Brings deoxygenated blood to the lungs.
What does the pulmonary vein do?
Takes oxygenated blood to the heart
What supplies the lungs with oxygenated blood?
The bronchial artery.
True or false: A bronchiole contains cartilage
False.
A bronchioles contains no cartilage or glands.
True or false: A bronchus contains cartilage and glands
True
Glands located in the submucosa
Cartilage reduced to small islands in the bronchus rather than whole circles in the primary bronchi
How are the bronchioles held open
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.
Where would you find a clara cell?
As bronchioles get smaller, goblet cells give way to clara cells, intersepted between ciliated cuboidal cells.
What do clara cells do?
Clara cells secrete a surfactant lipoprotein which prevents the walls sticking together during expiration.
How does epithelia change along the respiratory tract?
Initially pseudostratified –> simple columnar ciliated –> cuboidal
What can measuring clara cell protein tell you?
If it is lowered then there is lung damage.
If it is increased in serum then there is leakage across the air-blood barrier.
Why is it important we don’t have goblet cells in our bronchioles and further down?
To prevent individuals ‘drowning’ in their own mucus - not being able to cough it up and also prevents gaseous exchange.
At what point in the respiratory tract do the passageways begin to open to alveoli?
Respiratory bronchioles (which lead on from terminal bronchioles)
