Pulmonary Mod. 1 Structures&Function Flashcards
Structures of Upper Respiratory Tract
Nasal Cavity- conducts air, warm&humidifies
Pharynx–naso,oro,laryngo
Larynx
connects upper&lower respiratory tracts
epiglottis, thyroid, cricoid,
Trachea
high velocity of air
divides into R&L primary bronchi, continues to divide up to 23x.
bifurcatesa t carina
Primary Bronchi
bifurcates t carina
enters the hilum
Lobar Bronchi
3 on R, 2 on L
Segmental bronchi
divide off lobar branch
surgical lobes
10in R, 8 in L
Primary Fxn of Pulmonary System
gas exchange
Non-respiratory functions of Pulmonary System
phonation (larynx)
acid base balance
defense mechanism (airconditioning&olfaction)
metabolic function (vasoactive substances removed by lungs)
Filtration/removal of particles (ciliary action, reflexes in airway/irritant receptors-cough/sneeze)
Anatomy of conducting zone
upper respiratory tract to terminal bronchioles
no alveoli
first 16 generations of of tracheal tree
moves air into/out of conducting areas
What is anatomical dead space/where is it
air that comes into conducting zone but does not reach respiratory gas exchange regions (no gas exchange)
Mucociliary excalator
mucous traps foreign particles, cilia moves them towards pharynx (will be swallowed/expectorated/blown out of nose)
Respiratory Zone
respiratory bronchioles to alveolar scs
respiratory bronchioles–>alveolar sacs
Transitional Sections of Respiratory Zone
alveoli start at 17-19 divisions
Respiratory section of respiratory zone
alveoli completely at 20th-22nd generations
alveolar sac-23rd generation
Acinus
respiratory bronchioles–1st site of gas exchange)
alveolar duct–portion that is surrounded by the grape like cluster of the alveoli)
alveolar sacs–clusters of individual alveoli
Alveoli
primary gas exchange site
Epithelial Layer of Alveolar Septa
Type I alveolar cells:physical structure to alveoli
Type II: produces surfactant
Basement Membrane of alveolar septa
thin elastic layer that allows gas exchange
Defense of Alveoli
phagocytes/macrophages (ingest/remove foreign particles)
Wall and Lining of the Airways
Trachea-c shaped cartilage and smooth muscle
larger bronchi-smaller bronchi: cartilage becoming progressively diminished
Bronchioled: cartilage disappears
Tracheal Tree Wall Lining
Inner Layer: epithelial lining
Middle Layer: smooth muscle
Outer Layer: connective tissue
Mucous Producing Secreting cells
found along airway
Globlet cells: proximal to bronchioles
Clara cells: located in the terminal bronchioles
Pulmonary Circulation
Un-oxygenated blood from R.ventricle travels to pulmonary capillaries for gas exchange
also acts as a reservoir for for left ventricle
Bronchial Circulation
oxygenated blood from L. Ventricle supplies structures of pulmonary system
no gas exchange
bronchial arteries supply structures of lungs
Pressure and flow dynamics of pulmonary circulations
Low Pressure system (10-20 mmHg)
only 1/3 of pulmonary blood vessels filled
Pulmonary Capillaries
capillary beds surrounds each alveolar sac, allows alot of blood to be exposed to the gas in alveoli
Alveolocapillary Membrane
gas exchange membrane
- alveolar epithelium & basement membrane
- interstitial space
- capillary basement membrane & epithelium
1/10 of liter spread over area of 10mx10m
Hypoxic Vasoconstriction
if damage or pp of O2 drops, arterioles direct blood AWAY from the site
Functional Right to Left Shunt
some bronchial capillaries drain into pulm. veins return to left atria
bronchial (d.oxygenated) drain into pulm vein (oxygenated)
R to L shunt= un-oxygenated blood passing into oxygenated circulation
Pleura
dbl folded serous membrane
Visceral pleura-lines the lungs
Parietal Pleura-lines the chest wall
Pleural Space/Cavity
space between visceral & parietal layers
pleural fluid-secreted by pleura, normally thin layer within the pleural space, provides lubricant
Pores of Kohn
allows adjacent alveoli to exchange air between each other
Pressure in Pleural Space
low (negative/subatmospheric) -4 to -10mmHg
allows lungs to expand and “suck-in”outside air
