midterm 2 Flashcards
stretch Rc
slowly adapting lung stretch Rc
via vagus nerve can go back and inhibit inspiration
irritant Rc
constrict airway, cough
epithelial layer
J Rc
jextacapillary (lung tissue)
C- fibres
slow firing pain Rc
bronchoconstriction, mucous secretion and rapid shallow breathing (keep foreign out)
upper airway Rc
cause sneeze/ cough
joint and muscle Rc
increase ventilation
arterial BaroRc
decrease MAP sensed and increase ventilation and HR
pain and temp Rc
increase ventilation to react to pain
Bitter Rc
constriction of airway
related to asthma
ficks law
Vgas proportional to A/T x D x delta P
clinical implications of Ficks Law
- surface area: emphysema, mucous, cancer, aging, atelectasis (lung collapse)
- P gradient: altitude, increase Vd (deadspace) from cancer, and decrease VA (alveolar ventilation) from drugs
- thickness of alveolar membrane: increase fluid or mucous (pneumonia/inflammation), IPF and COPD
perfusion limited
when P1 = P2
diffusion limited
when P1 does not = P2 bad cause don’t become fully saturated (pick up enough O2)
recruitment
open all capillaries that were collapsed (with increase arterial pressure or venous pressure get distension)
distension
open wider the ones that were open already
circulatory function of lung
- gas exchange
- clear bl clots
- immune
- stem cells
- metabolism of vast active subs. (Inactivation–> NE/epi, brady kinin, serotonin, PGs. Activation–> AI –> AII 50x as a VC)
respiratory failure
inability to sustain expected level of Pr (force) production (apnea)
ventilatory failure
alveolar ventilation insufficient to eliminate CO2 therefore hypercapnia (pCO2> 50)
central failure
decrease central neural output (despite adequate or increased stimulation)
neuromuscular transmission failure
impaired transmission of AP across NMJ
peripheral muscle failure
impaired output
fatigue
loss in capacity for developing force and/ or velocity muscle, resulting from muscle activity under load and reversible by rest (RECOVERY)
- weakness is not reversible by rest
- attributed to muscle not nervous system
pathway for failure
brain–> spinal cord –> peripheral nerve
- -> NMJ
- -> muscle cell membrane–> transverse tubules–> Ca2+ release –> cross bridge formation
