Histo Pulm Flashcards
Where is air filtered when entering the body?
Nasal Cavities
Parts of the air condution system
Pharynx, larynx, trachea, bronchial tree
Responsible for the sense of smell
Olfactory mucosa
3 regions of nasal cavities
Vestibule, respiratory segment, Olfactory segment
Cell type of vestibule
Stratified squamous epithelium (continuous with the skin of the face)
Traps dust particle in the nasal cavity
Vibrissae
Function of the respiratory segment
Warm, moisten, filter inspired air
2 layers of the repiratory segment
Ciliated pseudostratified columnar epithelium and lamina propria
5 cell types of ciliated seudostratified columnar epithelium
Ciliated cells, goblet cells, basal cells, brush cells, small granule cells
Appearance of cilited cells
Tall columnar cells with motile cilia
Cells that synthesize and secrete mucus
Goblet cells
Forms the muscociliary apparatus
Goblet + Ciliated cells
Replacement cells that can differentiate into other respiratory epithelial cells
Basal cells (usually do not reach the surface)
Secretory cells that contain membrane-bound, dense-core granules at the base of the cell
Small granule cells
What respiratory cells are homologous to enteroendocrine cells?
Small granule cells
Contains extensive venous plexus near the inferior and medial nasal conchae to help warm up inspired air
Lamina propria
smooth portion of the respiratory system
Medial wall
Contains the turbinates of the respiratory segment
Lateral wall
Purpose of turbinates?
Increases surface area for warming and moistening of the incoming air. Also causes air turbulence for more efficient conditioning of the incoming air
How is the olfactory epithelium specialized?
Contains neurons and lacks goblet cells
Identifiers of olfactory cells
Nuclei are mostly within the middle of the epithelial layer
Bipolar neuron that spans the entire thickeness of the epithelium
Olfactory cell
Knob-like structure that the olfactory cell pole projects from
Olfactory vesicle
What is the apical surface of the olfactory dendrite covered in?
Immotile Cilia
What do the cilia of the olfactory cells contain?
Olfactory receptors
What forms the olfactory nerve?
Axons of the olfactory cells
Most numerous of the cell types in the olfactory epithelium?
Supporting or sustentacular cells
Appearance of sustenacular cells
Tall columnar cells with apical nuclei, apical surface covered in microvilli
Provides mechanical and metabolical support for the olfactory cells
Sustentacular cells
Progenitor cells that can differentiate into other types
Basal Cells
One of the very few neurons in the body that are replaced in postnatal development
Olfactory neurons
Contents of the lamina propria
Bowman’s glands (olfactory glands), unmyelinated axons, venous sinuses
Branched tubuloalveolar serous-secreting glands of the olfactory lamina propria
Bowman’s glands
Secretion of olfactory glands
Watery secretion
Lines the nasopharynx
Respiratory epithelium (ciliated pseudostratified columnar)
Layers of the trachea
Mucosa, submucosa, tracheal cartilage, trachealis muscle, adventitia
2 tissue types in tracheal mucosa
Ciliated pseudostratified columnar epithelium (respiratory epithelium) and lamina propria
What does the respiratory epithelium rest on?
Thick basement membrane with a well-developed reticular lamina, composed primarily of collagen
What part of the mucosa is well-developed in the trachea?
Elastic lamina propria
What is the tracheal submucosa composed of?
Loose connective tissue and seromucous glands
Separates the submucosa from the adventitia
Tracheal cartilages
Connects the free ends of each C-shaped cartilage
Trachealis muscle (smooth muscle fiber), not continuous muscle, and only on the posterior of the trachea
Most external layer of the trachea, binds the trachea to adjacent structures
Adventitia
Characteristics of bronchi
Cartilagenous plates and contiuous layer of smooth muscle
Parts of the walls of bronchi
Mucosa, muscularis, submucosa, discontinuous cartilagenous plates, adventitia
Cells that form the bronchi mucosa
Ciliated pseudostratified columnar epithelium with goblet cells over lamina propria, identical to trachea
Structure in bronchi lamina propria that can be used to differentiate bronchi from trachea
Bronchi-associated lymphatic tissue
Smooth muscle of the bronchi
Muscularis
What makes up the submucosa of the bronchi?
Loose connective tissue with glands and adipose tissue
Hyaline cartilage covered with perichondruim forms this as it decends all the way to the minor bronchi
Discontiuous cartilagenous plates
When does the bronchi turn into a bronchiole?
When the discontinuous cartilagenous plates disappear
Moderately dense connective tissue that is adjacent with that of the pulmonary artery and lung parenchyma
Adventitia
What is lacking in the walls of bronchioles?
Cartilage and glands
Largest to smallest lung tubes
Bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveoli
General cell type in the terminal bronchioles
simple cuboidal epithelium
2 types of cells in terminal bronchioles
Cuboidal cells with cilia, club cells
Cells in terminal bronchioles that assist in the transport of airway seretions up the bronchioles
Ciliated cuboidal cells
Specialized secretory cells in the terminal bronchioles
Club cells
Distinctive features of club cells
Well-developed RER/SER/Golgi apparatus, numerous secretory vesicles in the apical portion
Amount of smooth muscle in the terminal bronachiole
Significant amount
First brochioles to perform gas exchange
Respiratory bronchioles
Ratio of club cells to ciliated cuboidal cells in respiratory bronchioles
Large number of club cells
Amount of smooth muscle in respiratory bronchioles
little
At the end of the respiratory bronchiole
Alveolar duct
Spaces surrounded by clusters of alveoli
Alveolar sacs
Major site of gas exchange
Alveoli
Separates each alveoli
Alveolar septa
Make up the interstitium of the alveoli
Capillaries and connective tissue
Characteristics of the alveolar capillaries
Riches capillary network in the body, are continuous capillaries, lined with very thin endothelium.
2 main cell types in alveoli
Type I and Type II pneumocytes
Alveolar cell that is flattened, squamous, forms 95% of surface cells, joined to one another via occluding junctions, basal lamina are fused with endothelial cells of the tight capillaries
Type 1 pneumocyte
Makes up the air-blood barrier
Type I pneumocytes, endothelial cells, and fused basial laminae
Alveolar cell that is round, large, secretory, capable of mitosis
Type II pneumocyte
What granules do type II pneumocytes contain?
Multilamellar bodies, that contain surfactant
What is the purpose of surfactant?
Creates a film to reuce the surface tension inside alveoi, thus preventing their collapse
Which alveolar cell acts as a progenitor for the other?
Type II acts as a progenitor for type one
When the level of surfactant in infants is not enough to prevent collapsing of the alveoli
Respiratory distress syndrome
Connects neighboring alveoli
Alveolar pores
Purpose of alveolar pores
Equalize air pressure and provide collateral air circulation if a bronchiole is obstructed
Cells that ar epresent in spetal walls and alveolar spaces, collect particles like dust and pollen,
Alveolar macrophages
MOA of TB
Alveolar macrophages cannot digest the mycobacterium tuberculosis, so it accumulates in the cell, causing damage to the cell, which releases the stored bacteria, furthering the infection
Leading cause of mortality worldwide
Lung cancer
2 most common types of malignant tumors found in the lung
Non-small cell carcinoma and small-cell carcinoma
Most common cause of lung cancer
Non-small cell carcinoma
Most aggressive and highly malignant lung cancer that is almost always found in smokers
Small-cell carcinoma
