Respiratory System Flashcards
Conducting part of respiratory system
. Provides passageway for air to and from lungs
. Warms, moistens, and cleanses air
. Nasal cavities and assoc. paranasal sinuses, pharynx, larynx, trachea, bronchi, and most bronchioles
. Rigid walls to keep airway open
Respiratory part of the respiratory system
. Facilitates gas exchange btw blood and air
. Respiratory bronchioles, alveolar ducts, and pulmonary alveoli
Portions of conducting part of respiratory system
. Extrapulmonary portion
. Intrapulmonary portion
Epithelium in most of conducting part of respiratory system
. Psuedostratified, ciliated, columnar epithelium w/ goblet cells (respiratory epithelium)
. Thick basement membrane
Function of goblet cells in respiratory system
. Traps dust and potential infectious agents
Muco-ciliary escalator
Mucous layer propelled toward pharynx by coordinated movement of cilia covering columnar cells
Mucosa of conducting part of respiratory system
. Epithelium and lamina proprioception (CT)
Where are lymphoid cells found in conducting part of respiratory system
Epithelium and CT layer
Nasal cavity
. Initial portion lined w/ stratified squamous epithelium while other parts are lined w/ respiratory epithelium
. Respiratory epithelium supported by lamina propria w/ seromucous glands to moisten air and trap particles
. Lamina propria has superficial Venus plexus that warms air (reason for nosebleeds)
. Roof of nasal cavity lined w/ olfactory epithelium
In nasal cavity, the lamina propria is fused w/ ___
Perichondrium/periosteum coverings cartilaginous or bony skeleton of nasal cavity
Mucosa of nasal cavity Called ____
Mucoperichondrium or mucoperiostuem
Function of olfactory mucosa and components of it
. Detection of smell
. Basal cells, bipolar olfactory sensory neurons, and supporting (sustentacular) cells
Pharynx and larynx
. Lined w/ respiratory epithelium except in areas subject to abrasion (oropharynx, laryngopharynx, and epiglottis
. Have vocal cords
. Large masses of lymphoid tissue in lamina propria of nasopharynx forming Waldeyer’s ring
Vocal cords
. Projections of mucosa into lumen of larynx
. Covered in stratified squamous epithelium
Trachea
. Flexible tube of fibroelastic tissue reinforced w/ 12 C-shaped rings of hyaline cartilage
. Bands of smooth muscle (trachealis muscle) joint free ends of rings post.
. Surrounded by adventitia
. Lined by reparatory epithelium on thick basement membrane
. Lamina propria highly vascular w/ elastic fibers
. Submucosa has seromucous glands that dec. as you descend lower in trachea
. Submucosa merges w/ perichondrium that envelopes hyaline rings
Cells types in trachea epithelial lining
. Columnar ciliated cells
. Goblet cells
. Basal stem cells ( on basement membrane, don’t extend to lumen)
. Brush cells (columnar cells w/ micovilli, function as chemoreceptors)
. Small granule cells (Kulchitsky cells, neuroendocrine cells that produce serotonin, calcitonin, and other hormones
Bronchial tree
. Primary bronchi at Hilum
. Secondary (lobular) bronchi supply pulmonary lobe
. Tertiary (segmental) bronchi continue branching and form smaller bronchi and then bronchioles
Primary bronchus
. Wall similar to trachea
. Lamina separated from submucosa by smooth muscle layer that’s more prominent in distal bronchi
. Submucosa contains fewer glands than trachea
. Cartilage forms flattened plates
As bronchi become smaller, what occurs?
. Cartilage plates dec.
. Less goblet cells
. Thin lamina propria is completely encircled by spirally arranged smooth muscle
. Seromucous glands sparse
Bronchioles
. Less than 1 mm in diameter
. No cartilage or submucosa glands
. Psuedostratifed epithelium dec. in height from more simple columnar to cuboidal ciliated at terminal bronchioles
. Goblet cells replaced w/ club cells
. Smallest portion is the terminal bronchiole
Club cell
. Make 80% of epithelium at terminal bronchioles
. Protect bronchiolar epithelium
. Secret surfactant lipoproteins and mucins
. Detoxification of noxious substances (smooth ER)
. Secrete antimicrobial peptides and cytokines
. Replacement of other bronchiolar cell types
Respiratory bronchioles
. Final branching of terminal bronchioles
. Transition point from conducting to respiratory part
. Lined by simple cuboidal ciliated epithelium w/ club cells and scattered alveoli
. Give rise to alveolar ducts that are continuous w/ alveolar sacs (several alveoli in one sac)
Alveolus
. Sac-like evaginations from respiratory bronchioles, alveolar ducts and alveolar sacs
. 200-300 in each lung w/ total surface area of 75 m^2
. Wall has surface epithelium, interstitium and blood capillaries
Type I alveolar cells (type I pneumocytes)
. Super thin cell that line 90-95% of alveolar surface
. Provide barrier of minimal thickness that is permeable to gases
. Jointed by desmosomes and tight junctions
Type II alveolar cells (type II pneumocytes)
. Covers 5-10% of surface area but represents 60% of alveolar epithelial cells
. Cuboidal cells interspersed among type I cells
. Stem cells, can differentiate into Type I cell when they’re damaged
. Cytoplasm contains lamellar bodies (secretory granules w/ surfactant)
Pulmonary surfactant
Lowers surface tension at air-fluid interface
. Reduces tendency of alveolus to collapse at end of exhalation
Supporting tissue in respiratory portion of respiratory system
. Attenuated layer surrounding flood capillaries of alveolar wall
. Scatter fibroblasts, sparse ECM w/ reticular and elastic fibers
. Forms alveolar septa that separate alveoli
Alveolar pores
. Openings in alveolar septa that facilitate communication and aid in equalization of air pressure btw adjacent alveoli
Blood-air barrier
. Attenuated cytoplasm of type I pneumocytes
. Fused basal laminae of type I pneumocytes and of capillary endothelial cells
. Thin endothelial cells of capillary
Alveolar macrophages
. Dust cells
. Bone marrow-derived lymphoid cells that present in alveolar lumen and interstitium of alveolar septum
