Structure and Function of the Respiratory System Flashcards
what are the 7 functions of the oronasal zone?
- olfaction
- humidify and warm air
- thermoregulation
- filter air
- slows airflow
- phonation
- protect from aspiration during swallowing
got all the turbinates and sinuses for this function
describe the soft palate, epiglottis, and arytenoids during breathing
- soft palate is ventral and out of way of nasopharynx
- epiglottis lays over top of soft palate to allow air to larynx
- arytenoids are open to decrease resistance to air passing into the lumen of the trachea
describe the soft palate, epiglottis, and arytenoids during swallowing
- soft palate raises to protect airway
- arytenoids rotate down to open esophagus
- epiglottis rotates up to cover arytenoids/airway
all this is to protect from aspiration
what are the 2 functions of the conducting zone?
- filter air (via mucociliary apparatus)
- further slow air (provides the remainder of airway resistance)
does any gas exchange occur in the conducting zone?
nope! dead space
what is the function of the respiratory zone?
gas exchange! O2 and CO2
describe filtration of particles as move down the respiratory tract
vessel lumen gets much much smaller, so most larger particles are stopped higher up; only teeny tiny particles can get down to the respiratory zone; is a barrier to prevent infection
what are the 4 fates for particles that make it to the respiratory zone? (not a LO, just in case)
- remain in place, dealt with by inflammatory response and maybe also fibrosis
- alveolar macrophages come in a phagocytose those particles and carry them to the conducting zone
- endocytosed: across type I pneumocytes, through the interstitial space, into lympahtic drainage, and processed
- endocytosed across type I pneumocytes, through the interstitial space, packed into endothelial cells, and enter circulation
describe respiratory epithelium as move down the tract (4)
- in nasal cavity (classic respiratory epithelium) and pharynx (stratified squamous epithelium to provide a smooth, tough lining)
- in the trachea and bronchi have goblet cells and ciliated cells for mucociliary apparatus
- in the bronchioles, have club cells and ciliated cells for protection and movement
- in the alveoli, have type I and type II alveolar cells (more later)
why does respiratory epithelium change as you move down the tract?
form meets function!
1. epithelium gets progressively shorter
2. goblet cells and glands end at terminal bronchioles bc mucus would interfere with gas exchange in alveoli
3. ciliated epithelium and smooth muscle are present through the entire conducting zone; smooth muscle is under control of ANS
describe the layers of the mucociliary apparatus (4)
- fluid layers
1a. gel layer: high viscosity, traps particles, dilutes toxins, has antibodies
1b. sol layer: low viscosity so as to not impair the cilia it contacts - ciliated epithelium: synchronous movement (constant) clears mucus out of airways
- goblet cells/mucous glands: secrete mucous for gel layer
- BALT: secretes antibodies
list the 6 layers of the respiratory membrane
- fluid layer: includes surfactant from type II alveolar cell
- alveolar epithelium: type I alveolar cell for gas exchange
- epithelial basement membrane
- narrow interstitial space
- capillary basement membrane
- capillary endothelial membrane
list and describe the two types of alveolar/respiratory epithelial cells
type I: lining cells, over 96% of surface area of alveoli
type II: secrete surfactant; can proliferate and will differentiate into type I cells eventually
contrast respiration and ventilation
ventilation is moving air in and out of the respiratory tract, breathing
respiration is gas exchange
describe the 8 components of innate and acquired immunity in the respiratory tract (not a LO, just in case)
Innate:
1. PRRs
2. antimicrobial peptides
3. alveolar macrophages
4. monocytes
5. dendritic cells
6. neutrophils
acquired:
1. lymphocytes
2. antibodies
