Histology: principles, respiratory, cardio, GI. Flashcards
What lines the nasal cavity?
Keratinised stratified squamous epithelium
What lines the majority of the respiratory system?
Pseudostratified ciliated columnar epithelium with goblet cells, aka respiratory epithelium.
What lines the oropharynx?
Non-keratinized stratified squamous epithelium.
What is the larynx made up od?
Cartilage and muscles lines by respiratory epithelium
What is the trachea lined by?
Respiratory epithelium backed by a basal lamina, a lamina propria.
What are the bronchi lined by?
respiratory epithelium, and a lamina propria containing a discontinuous layer of smooth muscle and seromucous glands.
Describe the epithelium changes as you progress down the respiratory tree to the smallest bronchioles.
Epithelial cells decrease in height from columnar to cuboidal.
What lines the terminal bronchioles?
Cuboidal epithelium, with ciliated and non-ciliated club cells.
What lines respiratory bronchioles?
Discontinuous squamous type I alveolar cells.
What lines alveoli?
Type I and II alveolar cells (pneumocytes). Alveolar macrophages are also present.
Describe type I alveolar cells.
Simple squamous epithelium lining alveolar surface and permeable to gases.
Describe type II alveolar cells.
Polygonal, dense membrane bound lamellar bodies containing surfactant.
What are less common microbiological causes of community acquired pneumonia?
Mycoplasma pneumonia, coxiella burnetti, chlamydia.
How to confirm atypical pneumonia in lab?
serology of bloods (gold top vacutainer), PCR on swabs/secretions.
Mycoplasma pneumonia.
common cause of atypical community acquired pneumonia, highest incidence in children and young adults. Spread by person to person.
Coxiella burnetti.
Cause of pneumonia and Q fever. Uncommon, spread from sheep and goats to humans. Complications include culture negative endocarditis.
Chlamydophilia psittaci.
Causes psittacosis, uncommonly caught from pet birds. Usually presents as pneumonia.
What defences exist in the nasopharynx?
Nasal hairs, ciliated epithelia, IgA.
What bacteria typically colonises the URT?
Gram+ve: alpha-haemolytic strep. e.g. strep. pneumoniae, beta-haemolytic strep. e.g. strep pyrogenes, and staphylococcus aureus.
Gram -ve: haemophilus influenza, Moraxella catharalis.
Define pleura, and what is its hallmark of disease.
The pleura is a mesothelial surface lining the lungs and mediastinum. Mesothelial cells are designed for fluid absorption, and therefore the hallmark of pleural disease is pleurla effusion.
