NEETZoologyChemical Coordination and Integration
What is the effect of adrenaline and noradrenaline on heart beat, strength of heart contraction, and rate of respiration?
Options
- ADecreases
- BNo effect
- CIncreases
- DNo effect on heart beat but increases strength of heart contraction and rate of respiration
Correct answer
C. Increases
Step-by-step solution
The adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. These are commonly called as catecholamines. Adrenaline and noradrenaline are rapidly secreted in response to stress of any kind and during emergency situations and are called emergency hormones or hormones of Fight or Flight. These hormones increase alertness, pupilary dilation, piloerection (raising of hairs), sweating etc. Both the hormones increase the heart beat , the strength of heart contraction an