Respiratory System Flashcards
what are the respiratory system components?
- conduits for air passage
- muscles and CT for movement of gases to/from sites of exchange
respiratory system functions
- conduction of air
- conditioning of air
- gas exchange
- host defense
inspiration
active at rest through contraction of external intercostals and diaphragm
-enlarges thoracic cavity with less pressure than outside, so air can come in
expiration
passive at rest through elastic recoil of CT in lungs and chest wall
air conditioning
- inspired air is filtered to prevent entry of pathogens or irritants
- warmed and humidified in conducting portions to promote gas exchange and to prevent tissue damage due to cold air or desiccation
gas exchange
in highly specialized epithelia
-maximize surface area, and minimize diffusion distance
respiratory epithelium
from upper nasal cavity to bronchioles
- conducting portion with pseudostratified columnar with cilia
- respiratory portion with simple squamous
what are the 5 cell types in respiratory epithelium, and what are their functions?
- ciliated pseudostratified columnar epithelial cells (most abundant type; under the cilia are basal bodies)
- goblet cells (most abundant in larynx and trachea, diminishing in number thru bronchi; extend from basement membrane to lumen to secrete mucous)
- brush cells (extend from BM to lumen, with numerous microvilli sensory receptors that act as nerve endings on basal surface)
- basal cells (lie on BM, but are short and rounded; regenerative cells that undergo mitosis to give rise to other cells)
- granule cells (sit directly on BM; have numerous dense granules and may be part of neuroendocrine system to regulate mucous and secretions)
which respiratory epithelial cells extend to apical lumen, and which ones stay on basement membrane?
- ciliated, pseudostratified, columnar epithelial cells, goblet cells, and brush cells extend to lumen
- basal cells and granule cells stay on BM
mucociliary elevator
coordinated beating action of cilia propels mucous and trapped particles across aqueous layer towards mouth and nose to be swallowed or expectorated
-cilia go deeper in respiratory tract than goblet cells to prevent retrograde flow (so mucous doesn’t go down wrong way)
how are mucous and water layered over epithelial cells?
directly on top of cells are aqueous layer that contain the cilia (secreted from glands to provide low resistance environment)
-mucous float on top of water to catch any particles
Kartagener syndrome
genetic disorder where dynein is dysfunctional or absent
-needed for microtubule sliding in cilia movement, so there is no ciliary beating, and there are recurrent respiratory infections
vestibule
nostril
- transition from keratinized to respiratory epithelium
- sebaceous and sweat glands
- vibrissae (nose hair) for filtering particles
what are the parts of the nasal cavity?
- vestibule (nostril)
- fossae
fossae and their components
chambers in skull separated by bony nasal septum
- 3 conchae - bony projections covered with CT and epithelium
- -venous plexus in CT to warm air via swell bodies
- 3 meati - spaces between conhae for air passage
- -forces turbulent air flow to humidify and warm air
what are the inferior, middle, and superior conchae lined with?
inferior and middle - respiratory epithelium
superior - olfactory epithelium
olfactory epithelium and cell/gland types
lines superior conchae (10 square cm)
- supporting cells - microvilli, NOT cilia, with apical nuclei
- olfactory cells - bipolar neurons, basal nuclei
- basal cells - small, round, at base of epithelium, with basal nuclei; regenerative
- olfactory (Bowman’s) glands
- olfactory nerve bundle