Respiration intro Flashcards
External Respiration is?
gas exchange b/w external air ->
lungs ->
blood ->
tissues
Ventilation is?
convective mvmt of air into alveoli
Gas transfer (O2/CO2 ) in External Respiration occurs b/w?
alveoli and cells
In External Respiration, gas TRANSFER (O2/CO2) is through what mechanism?
Diffusion:
b/w alveoli and blood
b/w blood and tissue
In External Respiration, gas TRANSPORTATION by the blood is through what mechanism?
convection
Internal Respiration is?
intracellular metabolism
consumes O2
produces CO2
Alveoli are?
Do what?
small terminal sacs
site of gas exchange
Airway Path?
How many branchings?
nasal/oral cavities -> pharynx -> larynx -> trachea -> bronchi -> bronchioles -> alveoli
23 branchings
Conducting Zone is?
anatomical dead space:
made of 1st 16 branchings
(trachea to terminal bronchioles)
Respiratory Zone is?
gas exchange zone:
alveolar ventilation volume
branches 17-23
(respiratory bronchioles to alveolar sacs)
Bronchi anatomy?
2mm cartilage smooth mm submucosal gland pulmonary artery
Cartilage in bronchi affects diameter how?
rigid so doesn’t ∆ w/ lung volume
Bronchiole anatomy?
0.2mm
smooth mm
pulmonary artery
embedded in CT framework of lungs
θ cartilage in bronchioles affects diameter how?
diameter dependent on lung vol
Smooth mm of bronchi and bronchioles controlled by?
ANS (autonomic)
SNS control of smooth mm in bronch:
receptors?
action?
β2 receptor
airway dilation
PNS control of smooth mm in bronch:
receptors?
action?
M receptor
airway constriction
Terminal Respiratory Unit (acinus) is?
small airways and alveoli served by terminal bronchiole,
each TRU has 2000 alveoli
Respiratory bronchioles have wall that contain?
some alveoli
Alveolar ducts have wall that contain?
made entirely of alveoli
Trachea:
Cilia?
Smooth mm?
Cartilage?
yes
yes
yes
Bronchi:
Cilia?
Smooth mm?
Cartilage?
yes
yes
some
Bronchioles:
Cilia?
Smooth mm?
Cartilage?
yes
yes
no
Respiratory Bronchioles:
Cilia?
Smooth mm?
Cartilage?
some
some
no
Alveoli:
Cilia?
Smooth mm?
Cartilage?
no
no
no
Alveoli vasculature?
surrounded by pulmonary capillaries
in continuous sheet
Entire cardiac output goes to?
pulmonary artery ->
lungs
Pulmonary circulation pressure is?
low
20 cm H2O for 6L/min
Cytoplasmic diffusion distance thru pulmonary capillary is?
0.3 microns
Layers of blood-gas barrier b/w alveoli and pulmonary capillary? (3)
1) alveolar epithelium (type I cell)
2) interstitial fluid
3) capillary endothelium
Non-Respiratory Fxn of Lungs?
1) Acid/Base control
2) Metabolic fxns
Blood Acid/Base status controlled by?
CO2 and bicarbonate
Blood bicarbonate regulated by?
kidney
Blood CO2 regulated by?
How?
lungs
hyper or hypoventilation
short term control
Hyperventilation is?
↑ Valv
lower PaCO2 = less acid
alv = alveolar a = arterioles
Hypoventilation is?
↓ Valv
higher PaCo2 = more acid
Metabolic Fxns of lungs?
modify blood-borne material before return to circulation
What metabolic modifications are processed by the lungs? (4)
1) angiotensin converting enz (ang I to ang II)
2) activation of bradykinin, prostaglandins
3) seratonin uptake and storage
4) release IgA
Respiratory Exchange Ratio (RER)?
ratio of Vco2 to Vo2
Respiratory Quotient (RQ)?
same thing as RER
RER for fats?
0.7
RER for protein or mixed fat/carb?
- 8*
* assume this value if none given
RER for carbs?
1.0
Dalton’s Partial Pressures (of Inspired Air)?
Px = (Pb - Ph2o) Fx
Px = pressure of gas X in mmHg Pb = barometric pressure (760 mmHg) Ph2o = water vapor pressure at 37C (47mmHg) Fx = fractional [gas X] (0.21 for O2)
Boyle’s Law?
P1/P2 = V2/V1
P and V inversely related
Anatomical Dead Space is?
volume of inhaled air that does not take part in gas exchange:
remains in conducting airways,
or reaches unperfused alveoli
Symbols for Respiratory Physio:
C =
F =
Q =
R =
S =
V =
C = [gas] in blood
F = fractional concentration (%)
Q = vol of blood
R = respiratory exchange ratio
S = saturation of Hb w/ O2 (%)
V = vol of gas
