Respiratory Histology & Bio of Airways Flashcards
What layers make up the mucosa?
epithelium, basement membrane, lamina propria and muscularis mucosa
What layers are underneath the mucosa?
submucosa, adventitia- muscularis externa and hyaline cartilage
What is secreted to moisten the air in the nasal passages?
serous secretion and mucous secretion
What are the main functions of the respiratory system?
air conduction, filtration, gas exchange/respiration, carries stimuli for sense of smell, air passing through the larynx is used to produce sound/speech, involved in immune response against antigens in inhaled air, also endocrine
What is the cellular make-up of the vestibule?
stratified squamous, keratinized, and lamina propria
What is the defining characteristics of the respiratory epithelium in the nasal cavity and paranasal sinuses?
muco-cilliary escalator (airway defense mechanism), pseudostratified ciliated columnar cells (PSCC)- provides coordinated weeping motion of mucus, goblet cells- synthesize and secrete mucus, basal cells- stem cells give rise to other cells, enteroendocrine cells- small granule cells (Kulchitsky), and sensory receptor (brush cells)
Describe the make-up of the lamina propria?
mucous and serous glands, immune cells, and vascular network
What are the components of the muco-ciliary escalator?
serous and mucus secretion make a gel through action of the cilia, it traps particles and moves them up to be spit or swallowed
What are the components of olfactory receptor cells?
bipolar neurons, enlarged dendritic vesicle
What cells are in the olfactory mucosa?
olfactory receptor cells, sustentacular cells, basal cells, and serous glands
What is the make up of the soft palate in the nasopharynx?
Epithelium is PSCC on the nasal side and stratified squamous, non-keratinized on the oral side; Lamina Propria- MALT- Waldeyer’s Ring: palatine, lingual and pharyngeal (adenoid) tonsils
Describe the tissue makeup of the epiglottis.
lingual-stratified squamous, laryngeal- PSCC, Lamina propria- mixed mucous & serous glands, and elastic cartilage
Describe the tissue makeup of the larynx.
exposed cords- stratified squamous, protected areas (ventricle)- PSCC, lamina propria-seromucous glands and elastic fibers, intrinsic muscles- skeletal, hyaline cartilage (thyroid, cricoid & arytenoids)
Describe the tissue makeup of the trachea and Primary Bronchi.
epithelium-PSCC, goblet cells, and basal cells, enteroendocrine cells, receptor cells (brush cells), intermediate cells; basement membrane, lamina propria- loose CT with elastic fibers, lymphatic nodules, seromucous glands with myoepithelial cells; submucosa- mucous and seromucous glands- composed of mucus secreting acini with serous demilunes, rich blood, lymph supply, and nerves; adventitia- hyaline cartilage with smooth muscle trachealis
What are the components of the airway defense mechanisms? The function? Complications?
muco-ciliary escalator: goblet cells (gel), submucosal glands (sol & gel), ciliary cells; lines nasal cavities, sinuses & airways, balance between sol & gel, sol allows cilia to beat freely, gel floats above sol layer, moved up; complications: kartagener’s syndrome (dynein)- immotile, excess serous secretion (sol)- top, excess mucus production (gel)- bottom
Where does the cartilage stop in the lung tissue?
just before the terminal bronchioles
What is the makeup of the intrapulmonary bronchi?
Mucosa- PSCC epithelium with goblet cells, basal brush and small granule cells, lamina propria, muscularis mucosa: SM spirally encircles lumen, long elastic fibers, submucosa- seromucous glands, and adventitia with irregular cartilage plates, dichotomous branching, and elastic fibers
What is the makeup of bronchioles?
mucosa- simple ciliated columnar to cuboidal, no goblet cells, clara cells- nonciliated secretory cells, dome shaped, serous material to protect lining-Cl transport, stem cells, secrete surface active agent that prevents luminal adhesion, clara secretory protein (CC16), Lamina propria with thick muscularis mucosa, no glands, adventitia- no cartilage
What is the makeup of the alveoli?
Pores of Kohn-openings between adjoining acini; sacs- rotunda like space; ducts: opening channels from respiratory bronchioles, discontinuous wall of simple squamous or cuboidal, few smooth muscles, some elastic & collagen fibers; alveoli lines by capillaries for gas exchange
What is the makeup of the alveolar wall?
Type I pneumocytes, Type II pneumocytes, Alveolar macrophage (dust cell), Capillary Endothelial Cell, Interstitial cells: fibroblasts, mast cells, macrophages
What is the characteristic of type I pneumocytes?
squamous cell, lining of alveolus (97%), connected by occluding junctions & desmosomes
What is the characteristic of type II pneumocytes?
secretory cell, 3% of lining, connected by occluding junctions & desmosomes, lamellar bodies- make and secrete pulmonary surfactant
What is the function of the alveolar macrophage or dust cell?
capture and destroy particulates
What makes up the air-blood barrier?
surfactant lining, type I pneumocytes, epithelium basement membrane, interstitial space, endothelium BM, endothelial cell
