Question

quivering or spontaneous muscle contraction, especially of the heart, is called:
a thrombosis
b fibrillation
c patency
d embolism

Explanation:

Thrombosis is the formation of a blood - clot inside a blood vessel. Patency refers to the state of being open or unobstructed. Embolism is the blockage of a blood vessel by a foreign substance or a blood - clot. Fibrillation is the quivering or spontaneous muscle contraction, especially of the heart.

Answer:

B. fibrillation