QS Study

Heart rate is the speed of the heartbeat measured by the number of contractions of the heart per minute. A normal resting heart rate for adults ranges from 60 to 100 beats a minute. Generally, a lower heart rate at rest implies more efficient heart function and better cardiovascular fitness. For example, a well-trained athlete might have a normal resting heart rate closer to 40 beats a minute.

Many factors influence head rate as follows –

Factors increasing heart rate –

  1. ↓ Activity of Baroreceptor in arteries, It ventricle, and pulmonary circulation.
  2. Increased activity of the atrial stretch receptor (Bain-bridge reflex).
  3. Excess CO2.
  4. Inspiration.
  5. Hypoxia.
  6. Excitement.
  7. Anger
  8. Most painful Stimuli.
  9. Exercise.
  10. Epinephrine.
  11. Thyroid hormones
  12. Fever.

Factors that decrease heart rate-

  1. Increased activity of Baroreceptor in the arteries left ventricle and pulmonary circulation.
  2. Increase Infra cranial pressure.
  3. Expiration.
  4. Norepinephrine.
  5. Fear.
  6. Grief
  7. Stimulation of pain fiber in trigeminal nerve.