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Flashcards in Respiration Under Stress Deck (14):

Changes in ventilation during exercise

Ventilation increases



Neural component - rapid rise of ventilation at the onet of exercise

Central - cortex, HT, others

Peirpheral - muscle afferents, muscle spindles, tendon organs

Blood borne - slow, progressive increase in ventilation until stready state

Mild to mod - nochange in arterila blood gases despite increases in PCO2 and H+...and a decrease in PO2 of venous

Heavy - increases in arterial blood concentrations of H+, K+ and can further sitmulate peripheral chemoreceptors


Anaerboic threshold

THis is where the production of lactic acid begins

THIS is when the PaO2 and PaCO2 will begin to change


Resp response to exercise

Decrease in V/Q inequality
Increase in Diff caacity
Rightward ahiftr of O2 diss curve from increase in PCO2, H, and temp which facilitates O2 delivery
increase in cardiac output



V/Q increases all over, esp at bottom



Coughing, wheezing, SOB, usually 5-10 minutes after stopping exercise

From hyperventilation of cold dry air via mouth...caused by lrelease of leukotrienes, histamine, and other mediators that induce contraction

and/or increasing exposure to enviornmental triggers

Try breathign through the nose


Why hypoxia at high altitude

Less pressure means lower PO2 in inspired air...if lower PO2 in inspirated air, then lower alveolar PO2

Alveolar PCO2 does not really change as much


Mountain sickness

HEadache, fatigue, dizziness, palpitation, insomina, loss of appetite, nasuea

Hypoxia and alkalosis (increased pH due to hyperventilation that reduces PCO2)


Acclimation to high altitiude - hyperventilation


Rapid - stimulation of peripherla chemoreceptors by decrease in PO2

slow and progressive - alkalosis is alleviated by renal decreased reabsorption of bicarbonate

Increase in pH in CSF returned to normal


Other acclimation to high altitidue

Polycythemia - increase in RBC oce due to hypox induced relase of EPO from kidney...increase in RBC increases oxygen carrying capacity

Right shift of curve

INcreased capillary desnity in peripherla tissue

Hypoxia induces pulm vasoconstirction and HTN


O2 consumption after 4 days

After 4 days, climatized

Increased in ventilation continues due to gradual compensation



High pressure

Henry's law - dissolved nitrogen = Partial pressure times solubility


Decompression sickness

Formation of N2 bubbles in tisues during ascent after a deep dive

Joint pain, Neuro disturbances

Due a slow staged ascent

Breath helium-oxygen mix...helium has lower desntuy so less resistance...less soluble so less amount dissolved in tissue

Can be revered by tx in recompression chamber


Work of breathing dive

Increased airflow resistance because when gas volume reduced, density increased porprotionally which result in an increase in airflow resistance

Expansion of chest wall oppsosed by external compression generated by hydrostatic pressure