Histology Flashcards
Function of conchae.
increase respiratory surface area and aid filtration by creating eddies (circular movement) in the air stream
Lamina propria of respiratory region of nasal cavity is attached to:
underlying bone
Epithelial lining of:
- nasopharynx
- oropharynx
- pseudostratified ciliated columnar with goblet cells
2. stratified squamous, nonkeratinized
Epithelium over luminal surface of vocal cords:
stratified squamous
Thick ______ is characteristic of tracheal epithelium
basement membrane
How does structural wall change when bronchi become intrapulmonary?
- muscularis mucosa appears
2. cartilage now present
What is the function of Clara cells? (where?)
interspersed cells within non-PSCCE that secrete surface active agent (Clara cell protein) into bronchioles
What type of epithelium is present in bronchioles?
mostly pseudostratified ciliated columnar
small amount of simple columnar or cuboidal (have cilia; no goblet cells)
Well developed in bronchioles
muscularis
major regulator or airway resistance
Connective tissue lining with or without mesothelial lining
serosa or adventitia
CT that is often looser than lamina propria; surrounded by muscularis externa
submucosa
3 layers of mucosa
interior to exterior
epithelium
lamina propria
muscularis mucosa
Intrapulmonary portion of pulmonary tree (7)
- secondary bronchi
- tertiary bronchi
- bronchioles
- Terminal bronchioles
- respiratory bronchioles
- alveolar ducts
- alveoli
Lamina propria within mucosa of respiratory region contains: (3)
- rich vascular network
- seromucous glands
- lymphocytes and other immune cells
Epithelial lining of larynx
pseudostratified ciliated columnar with goblet cells and stratified squamous
4 layers of trachea
- mucosa
- submucosa
- hyaline cartilage
- adventitia
Epithelium of trachea
PSCC
Epithelium of
Respiratory bronchioles?
Bronchiole + Terminal bronchioles?
- ciliated cuboidal cells + clara cells proximally –> clara cells distally
- PSCC > simple columnar/cuboidal
Peripheral boundary of alveolar ducts
alveoli
ducts have almost no walls
Alveoli sacs
spaces surrounded by clusters of alveoli
alveoli open into sacs
Sites where gas exchange occurs
alveoli
Epithelium of type I alveolar cells
squamous
Epithelium of type II alveolar cells
cuboidal
What serves as stem cells for type I alveolar cells?
type II alveolar cells
Alveolar cells that secrete surfactant and proteins that participate in immune function
type II alveolar cells
Most gas exchange occurs in what portion of the alveolar septum?
thin region
What does the thin region of the alveolar septum consist of?
surfactant
type I epithelium and its basal lamina
an endothelial cell and its basal lamina
This portion of the alveolar sac allows cells to intervene between the epithelium of the alveolus and the capillary.
thick region
note: macrophages and fibroblasts are among cells in this area
Macrophages found in thick part of alveolar septum:
What is their function?
dust cells
scavenging inhaled particulate matter
What is the function of alveolar macrophages in heart failure?
scavenge RBCs
“heart failure cells”
What happens to engorged alveolar macrophages? (2 possibilities listed)
- reach the throat as mucus, where they are swallowed
2. retreat into septum and hang out there with their ingested material for years
Macrophages may digest _____, which aren’t digested and may reinfect.
tuberculosis
What are alveolar pores (of Kohn)? What is their function?
openings in interalveolar septa that allow air to pass between the alveoli; this provides air to alveoli where nml air pathway has been obstructed by pathological conditions
What is CC16?
marker for lung damage that is secreted by Clara cells
