Anatomy and histology Flashcards
Divisions of lower respiratory tract
Trachea, bronchus, terminal bronchiole, resp bronchiole, alveolar duct, alveolar sac, alveolus
What does an acinus comprise of? And what occurs here
It’s distal to the terminal bronchiole and comprises of: resp bronchiole, alveolar duct and sac.
Gas exchange occurs here
What does the larynx connect?
The trachea to the pharynx
What prevents the passage of food into the lungs?
The eppiglottis
What epithelium are the vocal chords and epiglottis covered in?
Non-keratinising squamous epithelium (similar to that lining the oral cavity, pharynx and oesophagus)
Embryologically, what do the lungs develop from?
An out pouching of the anterior wall of the primitive foregut at about the fifth week of development
Histology of resp tract (with the exception of the pharynx, epiglottis and vocal cords)
Ciliated columnar epithelia cells with mucus-secreting goblet cells and scattered neuroendocrine cells
Where is there cartilage in the resp tract?
Trachea + bronchi. From terminal bronchioles there isn’t any!
How many lobes in the lungs?
Right = 3 lobes (upper, middle, lower) Left = only 2 (upper and lower)
How many bronchopulmonary segments in each lung?
10
Each supplied by a bronchovascular bundle
Which cell type provide 95% of the surface area of the alveoli
flattened type I pneumocytes
Which cell type secretes surfactant?
rounded type II pneumocytes
What is beneath the alveolar cells?
Basement membrane and some interstitial matrix, including elastin fibres
What is the visceral pleura?
A thin layer of fibro-connective tissue and elastin with overlying mesothelial cells that encases the lung
What are the lungs surrounded by?
sit within the chest cavity, surrounded by parietal pleura, the diaphragm, ribs and intercostal muscles, vertebral column and sternum
