Respiratory System Flashcards
Why is the inferior aspect of each lung curved up?
It lies on top of the domed diaphragm
What 2 types of membrane does the respiratory system contain and where are they found?
A MUCOUS MEMBRANE which lines the conducting portion of the respiratory tract. It bears mucus-secreting cells to varying degrees.
SEROUS MEMBRANES which line the pleural sacs which envelope each lung.
Other than lubricating fluid, what may fill the pleural cavity
Air (pneumothorax)
Blood (haemothorax)
Pus (empyema)
A watery transudate or exudate (pleural effusion)
How can fluid be drained from the pleural cavity?
Fluid can be drained from the pleural cavity by inserting a wide-bore needle through an intercostal space (usually the 7th posteriorly). Nowadays done under ultrasound guidance.
When fluid is drained, precisely where is the needle inserted and why?
The needle is inserted a fraction above the superior border of the lower rib, thus avoiding the intercostal nerves and vessels, which run along the inferior border of each rib.
Intercostal nerves and vessels run in the costal groove along the inferior border of each rib
Below the 7th intercostal space there is a danger of penetrating the diaphragm.
How could cancer cause paralysis of the diaphragm?
Cancer of the lung can cause a paralysis of one side of the diaphragm, if tumour impinges on the left or right phrenic nerve.
How could lung cancer cause wasting of the lower arm muscles?
Cancer in the apex of the lung can impinge on the brachial plexus, causing wasting of muscles in the lower arm.
Some wasting of muscles of the thenar eminence, and some wastage of interosseus muscles in the palm due to the encroachment of the apical lung tumour on C8 and T1 nerve roots of the brachial plexus
What could cause Horner’s syndrome?
Cancer in the apex of the lung can impinge upon nerves called the sympathetic trunk, giving rise to Horner’s Syndrome, characterized by miosis (a constricted pupil), ptosis (a weak, droopy, upper eyelid), and apparent anhidrosis (localised, decreasd sweating).
There are other benign causes of this syndrome.
How could cancer cause a hoarse voice?
Cancer of the lung can result in a hoarse voice as a result of impingement on the left recurrent laryngeal nerve, which loops under the aorta.
An aneurism of the aorta can also cause such hoarseness.
What are the two portions of the respiratory tract?
Conducting portion of respiratory tract = nasal cavity to bronchioles.
Respiratory portion of respiratory tract = respiratory bronchioles to alveoli.
Name the components of the respiratory system from exterior to interior
CONDUCTING PORTION Nasal cavity Pharynx Larynx Trachea Primary bronchi Secondary bronchi Bronchioles Terminal bronchioles
RESPIRATORY PORTION
Respiratory bronchioles
Alveolar ducts
Alveoli
Which components of the respiratory system are extra pulmonary and which are intrapulmonary
EXTRAPULMONARY Nasal cavity Pharynx Larynx Trachea Primary bronchi
INTRAPULMONARY (within lungs) Secondary bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveoli
How do the thicknesses of the walls of the passageways compare to the diameter of the lumens
The walls become thinner as the lumen decrease in diameter
What kind of epithelium is found in the nasal cavity through to the largest bronchioles?
Psuedostratified epithelium with cilia and goblet cells
What type of epithelium is found in the smallest and terminal bronchioles?
Simple columnar with cilia and Clara cells but no goblet cells.
What kind of epithelium is found in the respiratory bronchioles and alveolar ducts?
Simple cuboidal with Clara cells and sparsely scattered cilia
What kind of epithelium is found in the alveoli?
Simple squamous/type 1 (+septal/type 2) cells
Describe the epithelium of the non-olfactory regions of the nasal cavity
Pseudostratified ciliated epithelium. Mucous glands and venous sinuses in lamina propria.