A L6 (Histology) Flashcards
What forms the URT and the LRT?
URT
nose, pharynx and associated structures
LRT
Larynx, trachea, bronchi, lungs wand tubing within lung + alveoli
What are the functional divisions of the resp system?
Conducting zone
Respiratory zone (responsible for gas exchange - alveoli)
What are the two types of mucous membranes in the nasal cavity? where they present?
- Olfactory mucosa
—-> Lines the roof of the nasal cavity (consists of olfactory receptors) - Respiratory mucosa
—-> lines the nasal cavity apart from the roof
What type of cells forms the respiratory epithelium?
pseudostratified ciliated columnar
What does the resp mucosa consist of?
- Pseudostratified ciliated columnar epithelium
- Goblet cells with epithelium
- Lamina propria (loose collagenous underlying layer)
What is the function of cilia in the respiratory mucous?
They move contaminated mucous (mucociliary escalator)
What is the function of nasal mucosa in terms of the air passing thru?
It warms (blood vessels), moistens and filters (through the mucous and cilia) the air
What is the muscle that connects the ends of cartilages in the trachea?
Trachealis muscle
What are the types of cells present in the respiratory epithelium (RE) in the trachea
- Tall pseudostratified ciliated columnar epithelium cells
- Goblet cells
- Serous cells
- Neuroendocrine cells
- Stem cells
What are the 4 layers that form the trachea?
- Resp epithelium
- Lamina Propria (loose, highly vascular supporting tissue)
- Submucosa (mixed seromucinous glands)
- Fibroelastic tissue between cartilage rings
Where is smooth muscle present in the trachea?
Its present in small bundles mainly in the fibroelastic tissue which is located between the cartilage rings (behind the trachealis muscle)
What is lamina propria?
It is loose, highly vascular supporting tissue
Where are mixed seromucinous glands present in the trachea?
IN THE SUBMUCOSA
Where is the fibroelastic tissue present in the trachea?
Between the C-shaped cartilage rings
What are the changes in tissue composition as you move down the resp tract?
- The supporting connective tissue (cartilage) changes ::: The c-shaped cartilage rings are replaced by cartilage plates
- The type of epithelium lining the trachea changes (it decreases in height):
—-> Goes from pseudostratified columnar epithelium —> Simple columnar —-> Simple cuboidal - There’s and increase in the amount of smooth muscle present
List the divisions of the resp tract as you move down it. And state which ones are conducting vs respiratory zone
CONDUCTING ZONE:
Trachea –> Main/primary bronchus –> Lobar/secondary bronchus –> Segmental/tertiary bronchus –> Bronchioles –> Terminal bronchiole
RESPIRATORY ZONE:
Respiratory bronchiole –> Alveolar duct –> Alveolar sac
What is the last division of the conducting zone
Terminal bronchiole
What is the first division of the respiratory zone?
Respiratory bronchioles
What is the role of clara cells? Where are they found
Found in the respiratory bronchioles
- Secrete surfactant
- Act as stem cells
- Contain enzymes that detoxify substances
Pseudostratified ciliated columnar epithelium
Nasal mucosa
– RE - epithelium
V - BVs
S - serous glands
M - mucous glands
Resp. epithelium (pseudostratified ciliated columnar with goblet cells)
w/ layer of lymphoid tissue below (nasopharyngeal tonsils/adenoids)
What structure? Name the 4 layers
Trachea
- Resp epithelium (pseudostratified ciliated columnar with goblet cells, serous cells, neuroendocrine cells and stem cells )
- Lamina propria ( loose, highly vascular supporting tissue)
- submucosa (seromucinous glands)
- Fibroelastic tissue (btwn cartilage)
Which layer would a majority of the vasculature be located in the trachea
in the lamina propria
What is the function of neuroendocrine cells?
They secrete hormones that regulate muscle tone
(present in trachea and bronchioles)
Differentiate between how the structure of the airway changes as you move further down in terms of epithelium, the layers of tissue, cartilage, supporting tissue present (lamina propria), smooth muscle, glands
Look at google doc
