reparatory system Flashcards
work of respiratory system
compliance- lungs are very stretchy to ensure the least amount of work to breathe
driven by pressure differences
work is required to stretch the tissue and increase the surface area of water molecules
surface tension
a measure of work required to increase the surface area of the liquid
surfactant (produced by type II alveolar cells decreases the surface tension by decreasing the attraction between water molecules
resistance
impacted mostly by radius of airway
resistance in healthy lungs is low
large surface area also helps combat resistance
factors impaction- passive forces, smooth muscle contraction, and mucus production
obstructive respiratory diseases
an increase in airway resistance
emphysema and chronic bronchitis (inflammation of airways)
COPD - chronic (enlarged alveoli)
asthma- acute (contraction of smooth muscle in airway, inflammation, excess mucus)
restrictive respiratory diseases
decreased Lung compliance
caused by scarring in airways, additional weight on pulmonary cavity, deformations of the thoracic cavity
pulmonary fibrosis, scoliosis, obesity
reduced lung volumes, difficult to get air in
how to calculate FVC (forced vital capacity) or VC (vital capacity)
tidal volume (Vt)+inspiratory reserve vol (IRV)+ expiratory reserve volume (ERV)= FVC
how to calculate TLC (total lung capacity)
tidal volume (Vt)+IRV+ERV+residual vol (RV)= TLC
how to calculate inspiratory capacity (IC)
tidal volume + IRV= IC
how to calculate minute ventilation
tidal volume x respiration rate
how to calculate alveolar ventialtion
(tidal volume x RR) - (dead space volume x RR)= Alveolar ventilation
partial pressure
gasses follow their own partial pressure
depends on total concentration and total pressure
arterial blood O2 and CO2 relatively constant
O2 moves from alveoli to blood at the same rate as its consumed by cells
Co2 moves at the same rate from blood to alveoli as it is produced by cells
Pressure depends on metabolic activity, greater metabolic activity means lower pressure and greater diffusion
diffusion at the lungs
oxygen loading of the hemoglobin occurs at the alveoli
diffusion occurs at the lungs capillaries within the first 1/3.
saturates to 98%
takes 0.25 of a second
May be a limitation in elite athletes (most commonly males)
- Due to higher CO
transport of O2 and CO2
law of mass action state the more oxygen present the more will bind to hemoglobin
oxygen is transported by hemoglobin
carbonic anhydrase converts CO2 to water and carbonic acid
chloride shift is when bicarbonate gets exchanged for chloride at the rbc.
carbamino effect
effects of the offloading of CO2 on O2, the less CO2 that can be removed from hemoglobin the less oxygen can load on
2,3 DPG effect
at altitude more red blood cells are produced because of low O2
decreases hemoglobins affinity for O2 which enhances O2 unloading