Histology of the Respiratory Tract

Question 1

What function to cilia have in the respiratory tract?

What cells are found amounts cilia in the respiratory tract?

Answer 1

muco-ciliary escalator
move mucus up and out, takes microbes and foreign particles with it
goblet cells which produce mucus

Question 2

What is respiratory epithelium and where is it found?

Answer 2

ciliated, pseudo stratified, columnar epithelium

lines the respiratory tracts

Question 3

What is the general structure of olfactory epithelium?

Answer 3

pseudo stratified epithelium containing bipolar olfactory neurones, support cells and basal stem cells

Question 4

What epithelium covers each of the following structures? Anything else of interest in these areas?:

1. skin of nasal cavity
2. lateral wall of nasal cavity
3. cribriform plate/roof of nasal cavity
4. nasopharynx
5. epiglottis
6. trachea
7. bronchioles
8. respiratory bronchioles
9. alveoli
10. pleura

Answer 4

1. keratinised stratified squamous epithelium
2. pseudo stratified columned epithelium, highly vascularised
3. olfactory epithelium
4. pseudo stratified columnar epithelium
5. stratified squamous epithelium
6. pseudo stratified columnar epithelium, mucus glands, c-shaped cartilage rings
7. pseudo stratified columnar epithelium, elastic fibres, circular cartilage
8. simple cuboidal, no cartilage, Clara cells (innate immune and surfactant secretory functions)
9. simple squamous epithelia
10. simple squamous mesothelial cells, interstitial fluid

Question 5

Alveoli are surrounded by three main cell types. What are they and what is their function?

Answer 5

Type I pneumocyte - gaseous exchange
Type II pneumocyte (larger and rounder) - surfactant secretion
Macrophages within the walls

Question 6

What are the specific layers of the olfactory mucosa, superficial to deep?

Answer 6

mucus layer
olfactory epithelium
lamina propria
cribriform plate
olfactory bulb

Question 7

Over which regions of the nasal cavity does the olfactory epithelium extend in humans?

Answer 7

covers superior conchae at roof of nasal cavity

Question 8

Draw a labelled diagram of the alveolar membranes and septum i.e. blood-gas barrier

Answer 8

..

Question 9

Where are Bowman’s glands located? What do they produce and why?

Answer 9

In olfactory epithelium
Produce watery secretions
To dissolve odor particles