HIST Respiratory Flashcards
- List 5 functions of the Respiratory System.
- Air conduction, conditioning and filtration
- Respiration (gas exchange)
- Speech production
- Sense of smell
- Regulate immune response to inhaled antigens
- What is the classification of epithelium in the vestibule of the nasal cavity?
a) stratified squamous epithelium
b) simple squamous epithelium
c) pseudostratified columnar epithelium
d) stratified cuboidal epithelium
a) stratified squamous epithelium
This also contains stiff hairs (vibrissae) and sebaceous glands.
NB: The vestibule is the opening of the nasal cavity, preceeding the respiratory region.
Regarding (c), pseudostratified columnar = the olfactory epithelium.
- Describe the olfactory segment of the nasal cavity with regard to:
- location
- epithelial classification
- cell types
- lamina propria components
Location - small area of mucosa on the roof of nasal cavity.
Classification - pseudostratified columnar
Cell types - x4
- olfactory receptor (neural)
- sustentacular
- brush
- basal
LP - contains connective tissue, olfactory nerve fibres, blood & lymphatic vessels and serous-mucous glands & ducts.
- Describe the assymetrical differences of the olfactory bipolar neuronal cells.
Apical
- ~ 20 cilia/cell
- 200 um long
- limited motility
- single dendrite extends into lumen
Basal
- axonal process leaves cell and enters LP to form CN1 (olfactory nerve)
NB: function = smell
- Which of the following is incorrect regarding sustentacular cells?
a) most common cell type in olfactory epithelium
b) columnar epithelia with cilia
c) Nucleus in an apical position
d) zonula adherens between olfactory & sustentacular cells
e) They have a metabolic function and a physical support role
incorrect: b) columnar epithelia with cilia
- the columnar epithelia has microvilli (not cilia)
- Difference between cilia & microvilli:
- microvilli = absorption. Length ~ 0.5-1.0 um, diameter ~0.1 um (much smaller)
- cilia = rhythmic movement (sweeping). length ~ 5-10 um, diameter ~ 0.2 um
Regarding:
d) zonula adherens = intermediate junction, usually more basal than tight junctions.
e) metabolic function is to secrete odorant-binding proteins
- Differentiate basal cells from brush cells.
Function:
- Basal - stem cellular; differentiate into sustentacular cells
- Brush - sensation; basal plasma membrane synapses with axons from trigeminal nerve (CN5)
Morphology:
- Basal - small, round cells
- Brush - cuboidal
Other:
- Brush cells’ nuclei are in basal positions
- What classification and cell types constitute respiratory epithelium?
Pseudostratified Columnar Epithelium
Cells:
- ciliated
- columnar, more elongated nuclei toward the top of epithelium
- NB opposite to this - sustentacular (supporting) cells have microvilli
- goblet
- triangular shaped nucleus
- brush
- basal (stem cellular)
Other notes:
- rest on a thick basement membrane
- no bipolar neurons
- Name the following type of epithelium and four cell types present (not just the arrow):
