Question

A steroid hormone which regulates the rate of heartbeat is_____.

• A. adrenaline
• B. thyroxine
• C. parathormone
• D. growth hormone

Answer 1

The correct option is A

adrenaline

Adrenal medulla produces two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. Both these hormones act on tissues and organs that are supplied by sympathetic fibers and produce similar effects. Thus adrenal medulla and sympathetic system function as a closed integrated unit and is known as sympathetico -adrenal system. Adrenaline specifically regulates SA node which increases heartbeat in emergency conditions to cope up with increased blood supply to the organs.