Factor
|
Effect
|
Cardioaccelerator nerves
|
Release of norepinephrine
|
Proprioreceptors
|
Increased rates of firing during exercise
|
Chemoreceptors
|
Decreased levels of O2; increased levels of H+, CO2, and lactic acid
|
Baroreceptors
|
Decreased rates of firing, indicating falling blood volume/pressure
|
Limbic system
|
Anticipation of physical exercise or strong emotions
|
Catecholamines
|
Increased epinephrine and norepinephrine
|
Thyroid hormones
|
Increased T3 and T4
|
Calcium
|
Increased Ca2+
|
Potassium
|
Decreased K+
|
Sodium
|
Decreased Na+
|
Body temperature
|
Increased body temperature
|
Nicotine and caffeine
|
Stimulants, increasing heart rate
|