Flashcards in Respiratory System Deck (80)
What are the functions of the respiratory system?
- air conduction/gas exchange
- heat regulation
- air "conditioning" (temp and moisture control)
- acid-base regulation
- hormone conversion
What are the subdivisions of the respiratory system?
- conductive system
- transitional system
- gas exchange system
What structures are part of the conductive system?
nasal cavity, pharynx, larynx, trachea, and bronchi
What structures are part of the transitional system?
What structures are part of the gas exchange system?
respiratory bronchioles and alveoli
What does the conducting system do?
- brings air to the respiratory portion
- cleanses, moistens and warms incoming air
- blood in venous plexuses in mucous membrane of nasal cavity regulates temperature of inhaled air
- hair and secretions in the nasal cavity trap particulate matter
What is the transitional system?
a transition zone between the conducting (ciliated) and the gas exchange (alveolar system) areas of the respiratory tree
- consists exclusively of terminal bronchioles
What are the terminal bronchioles lined by?
- clara cells
- non-ciliated secretory cells
- only a few ciliated cells
- healthy bronchioles do not have goblet cells
What is the exchange system composed of?
alveoli; thin walled structures enveloped by a rich network of capillaries: the pulmonary capillaries.
What are alveoli lined by?
epithelial type I (membranous) and type II pneumonocytes (also known as pneumocytes)
What is the path of air into the lungs?
Nasal cavity -> nasopharynx -> larynx -> trachea -> bronchi -> bronchioles -> respiratory bronchioles -> alveolar ducts -> alveolar sacs -> alveoli
What are the non-specific defense mechanisms of the respiratory system? (non immune mediated)
- mucous trapping
- Mucociliary clearance (mucociliary escalator)
- Air turbulence (generated by coughing and sneezing)
What are the specific (immune-mediated) defense mechanisms of the respiratory system?
- antibody production
- antibody-mediated phagocytosis
- Cell-mediated immunity
What lines the nasal cavity, pharynx, larynx, trachea, and bronchi?
pseudostratified ciliated columnar epithelium with secretory goblet cells and submucosal serous cells
What does the lamina propria of the nasal cavity contain?
tubulo-alveolar glands, mainly serous with lesser numbers of mucous and mixed glands
What does the olfactory epithelium of the nasal cavity contain?
olfactory sensory cells
What is the nasal cavity?
bone supported cavity within the skull divided by nasal cartilaginous septum into two halves: left and right.
What are the three regions of the nasal cavities?
- vestibular region
- respiratory region
- olfactory region
What is the vestibular region of the nasal cavity?
initial external part of the nasal cavity that has a cutaneous mucous membrane, haired skin and glands
What is the vestibular region lined by?
stratified squamous keratinized epithelium
What is the respiratory region of the nasal cavity? What is it lined by?
the largest part of the nasal cavity lined with pseudostratified columnar ciliated epithelium with goblet cells.
What is the mucociliary apparatus and what is it responsible for?
combination of pseudostratified columnar ciliated epithelium with goblet cells that is responsible for clearance
- movement of cilia removes mucus with trapped airborne particles such as dust and microorganisms.
- cleaning apparatus of upper respiratory system
What are the projections from the lateral wall of the nasal cavity (respiratory region) called? What do they do?
conchae turbinates - narrow the lumen of the nasal cavity and increase the area of contact of inhaled air with respiratory mucous membrane, thus regulating the quality and quantity of inhaled air
Where are goblet cells found in the upper respiratory tract?
present along the airways to the level of the large bronchioles
What traps particulate matter in the upper respiratory tract?
secretion from the goblet cells
How does the respiratory system react to injury of the upper respiratory tract?
- increase numbers of goblet cells (hyperplasia) (eg: in smokers)
- metaplasia (a change from ciliated stratified epithelium to squamous stratified epithelium
What is present on the tips of the cilia in the URT?
claws of dynein
What is kartagener's syndrome?
dysfunction caused by immotile cilia syndrome - dynein claws missing
What is the olfactory region lined by? Where is it located?
lined with olfactory epithelium, much thicker than respiratory epithelium and lacks goblet cells
- located in the dorsal part of the nasal cavity (olfactory region)