Respiration Under Stress

Question 1

Changes in ventilation during exercise

Answer 1

Ventilation increases

Question 2

Hyperventilation

Answer 2

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

Question 3

Anaerboic threshold

Answer 3

THis is where the production of lactic acid begins

THIS is when the PaO2 and PaCO2 will begin to change

Question 4

Resp response to exercise

Answer 4

Hyperventilation
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

Question 5

V/Q

Answer 5

V/Q increases all over, esp at bottom

Question 6

EIA

Answer 6

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

Question 7

Why hypoxia at high altitude

Answer 7

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

Question 8

Mountain sickness

Answer 8

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

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

Question 9

Acclimation to high altitiude - hyperventilation

Answer 9

Hyerventilation

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

Question 10

Other acclimation to high altitidue

Answer 10

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

Question 11

O2 consumption after 4 days

Answer 11

After 4 days, climatized

Increased in ventilation continues due to gradual compensation

Question 12

Diving

Answer 12

High pressure

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

Question 13

Decompression sickness

Answer 13

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

Question 14

Work of breathing dive

Answer 14

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