Question

Your heart works by:

(1 point)
Responses

entirely voluntary muscle contraction.

entirely voluntary muscle contraction.

entirely involuntary muscle contraction.

entirely involuntary muscle contraction.

a balanced mix of voluntary and involuntary muscle contraction.

a balanced mix of voluntary and involuntary muscle contraction.

almost entirely involuntary muscle contraction, but sometimes voluntary contraction.

Answer 1

almost entirely involuntary muscle contraction, but sometimes voluntary contraction.

Answer 2

No guessing

Answer 3

almost entirely involuntary muscle contraction, but sometimes voluntary contraction.