Question

Frog's heart when taken out of the body continues to beat for some time.
For the reason behind this, select the best option from the following statements.
(a) Frog is a poikilotherm.
(b) Frog does not have any coronary circulation.
(c) Heart is "myogenic" in nature.
(d) Heart is autoexcitable

• A. only (d)
• B. (a) and (b)
• C. (c) and (d)
• D. Only (c)

Answer 1

The correct option is C (c) and (d)

A myogenic heart is capable of generating a cardiac contraction independent of nervous input. In frogs, heart is myogenic in nature which means the impulse originates in muscle tissue and not from a nerve impulse. The heart is also autoexcitable, which means it has the ability to generate action potentials without any external stimuli. The frog’s heart taken out of the body continues to beat for as long as ATP is available.