Respiratory Histology Flashcards
What are alveolar sacs?
2+ clusters of alveoli
What is the order of path from a bronchiole to an alveolus?
terminal bronchiole –> respiratory bronchiole –> alveolar duct –> alveolar sac
What is the function of the conducting portion of the respiratory system?
What parts make it up?
collects and warms air --> transmits to respiratory part nasal cavities, sinuses trachea primary, secondary, and tertiary bronchi bronchioles, terminal bronchioles
At what point in the respiratory tract do you stop seeing goblet cells, glands, and hyaline cartilage?
in the bronchioles
What type of epithelium lines the olfactory region of the nasal cavities?
How is it different than respiratory region?
pseudostratified ciliated columnar
much thicker and lacks goblet cells
has olfactory glands –> serous secretions that dissolve odorant molecules
What are the characteristics of terminal bronchioles?
simple cuboidal epithelium w/ clara cells
increased elastic fibers
1-2 layers smooth muscle
What are the 4 layers of the trachea?
mucosa (ciliated pseudostratified columnar w goblet cells)
submucosa (denser CT than lamina propria)
cartilage
adventitia - binds trachea to adjacent structures
What are the characteristics of olfactory receptor cells/neurons?
have single dendritic process
nonmotile cilia w/ odorant receptors
ligand binds –> signal to olfactory bulb
What is special about the lamina propria of the respiratory epithelium?
has a rich vascular network w/ complex set of capillary loops
What layer of the trachea contains glands to coat the mucosa?
submucosa
glands = submucosal glands
What are the characteristics of type I pneumocytes?
very flat, line almost the entire alveolar surface
create surface for gas exchange w/ capillaries
What layer of bronchi contains the irregular cartilage plates?
submucosa
What are the 3 regions of the nasal cavities?
nasal vestibule - just inside nostriles, lined by skin
respiratory region - inferior 2/3, lined w/ respiratory mucosa
olfactory region - upper 1/3, lined w/ olfactory mucosa
How do goblet cells secrete mucus?
mucigen granules released through exocytosis –> combine w/ water –> mucus
What are the characteristics of visceral pleura?
covered in mesothelium
underlying fibrous CT of collagen and elastic fibers
extends into lung as septa continuous w/ lung parenchyma
contains a lot of lymphatic vessels
What is emphysema caused by?
smoking cigarettes
chronic inhalations of particulate material
What layer of the trachea contains BALT?
epithelia
What are the major characteristics of bronchioles?
airways < 1 mm
clara cells in epithelia
increased elastic fibers in epithelia
no submucosa or cartilage
What is the function of nasal cavities?
adjust the temperature and humidity of inspired air (enhanced by large surface area from turbinate bones)
What type of epithelium lines the respiratory region of the nasal cavities?
pseudostratified columnar ciliated with goblet cells
What is pneumonia?
inflammation of lung tissue
air spaces filled w/ exudate containing WBCs, RBCs, and fibrin
enlarged capillaries congested w/ RBCs –> lung appears red, firm, and heavy
What are the two types of drugs for asthma?
short term bronchodilators
long term corticosteroids
What are the main types of cells in the alveoli?
type I and II pneumocytes
macrophages
What are the major differences between bronchi and the trachea?
no regular rings of cartilage - irregular plates
smooth muscle layer present that is continuous in larger bronchi and loosely organized in smaller ones
fewer submucosal glands and goblet cells
What type of tissue lines the pleura?
mesothelium
What is emphysema?
chronic obstruction of airflow due to narrowing of bronchioles –> destruction of alveolar wall –> significant area for gas exchange is lost
Where do olfactory neurons lie?
in the middle of the olfactory mucosa
What are alveolar pores?
small openings that permit movement of air btw alveoli
What are the characteristics of type II pneumocytes?
rounded cells that are 60% of the cells, but cover 5% of SA
secrete surfactant from lamellar bodies –> exocytosis
What are basal cells of olfactory mucosa?
stem cells for olfactory receptor and supporting cells
What are the main cell types in olfactory mucosa?
olfactory receptor cells
basal cells
brush cells
supporting/sustentacular cells
What type of epithelium is found in alveoli?
simple squamous
What is an alveolar septum?
wall of alveolar capillaries surrounded by elastin and collagen fibers
When do you stop seeing simple ciliated columnar epithelium and start seeing simple cuboidal?
in the small bronchioles
What are clara cells?
cells that secrete lipoprotein surfactant for the lungs
found in bronchioles and terminal bronchioles
At what point in the respiratory tract do you stop seeing ciliated cells?
after respiratory bronchioles (once you reach alveolar ducts)
How does asthma affect the airway?
chronic inflammation –> brochiolar walls infiltrated w/ eosinophils, lymphocytes, and mast cells –> super thick epithelium w/ more goblet cells, thick BM and hyperplastic smooth muscle –> makes airway chronically smaller and harder to move
What are alveolar rings?
aggregates of smooth muscle, collagen, and elastic fibers that form rings around alveolar ducts
what length of respiratory tract is considered the trachea?
from larynx into the primary bronchi
What type of epithelium lines the respiratory tract?
pseudostratified columnar ciliated epithelium
with goblet cells
(confined to airways)
What is the purpose of the respiratory portion of the system?
What parts make it up?
passes air to alveoli –> gas exchange
respiratory bronchioles, alveolar ducts, alveolar sacs
How is the epithelium in bronchi different than the trachea?
cells shorter in height in bronchi
fewer goblet cells
increased elastic fibers in LP
