Review Materials Flashcards
Pulmonary surfactants reduce work required to expand the lung because…
they reduce surface tension at the air water interface.
- Area Dependent
- Prevents small alv. collapse
- Increase compliance
Rate of Diffusion of Gas Across a membrane?
(area of membrane)(diffusion coefficient)(Difference of Partial Pressures) / (Membrane Thickness)
Increased V/Q ratio means?
Unperfused Alveoli
Decreased V/Q ratio means?
Unventilated Alveoli
What molecular components of hemoglobin lead to cooperativity?
Histidine residue movement breaking salt bridges
What does carbonic anhydrase do?
Catalyzes CO2–>H+HCO3
Hypothemia is usually caused by
Low ambient temperature and certain surgical procedures
Hyperthermia is usually caused by
High Temp + Humidity + Exertion
Why is air flow in the alveoli nearly zero?
Cross sectional area increases dramatically at each branch. Causes air flow to drop to practically zero
Basic difference between obstructive and restrictive lung disease?
Obs. – Inc. Airway resistance causes a decrease in FEV/FVC.
Restrictive – Have a dec. FRC, so FEV/FVC rises
Why does hypothermia get worse in water?
Water has a greater conductive ability than air
Three modes of thermal regulation.
Vasomotor - Changes in skin BF
Metabolic - Shivering/Vol. Exer.
Sudomotor - Sweating + other two
Fever is the result of…
resetting the hypothalamic thermostat with pyrogens
Transection at the caudal medulla results in _____
no more respiration
Transection at the pontomedullary junction results in
Gasping
Define Tidal Volum
Normal volume of air taken in and out in a single breath
Define inspiratory capacity
the volume of air that can be inspired (TV+IRV)
Define vital capacity
Total volume that can possible be inhaled+exhaled (IRV+TV+ERV)
Define Forced Expiratory Volume
Volume of air that can be expelled in 1 second
Define forced vital capacity
Total air expelled forcibly after inhale to TLC
Why is shallow breathing less useful?
Air remains in the dead space collecting higher levels of CO2
Membrane resistance is…
resistance of a gas across a membrane. In our case O2 over endothelial cell layer, plasma, and erythrocyte mem
Chemical reaction resistance…
resistance to O2 movement cause by rxn of hemoglobin + o2
Two anatomical shunts…
Coronary Blood to left ventricle
Blood through lungs that hits unperfused territory
