Heart rate is increased by all the following except:

Heart beats are accelerated by

Cardiac activities of the heart are regulated by:
$A.$ Nodal tissue
$B.$ $A$ special neural centre in the medulla oblongata
$C.$ Adrenal medullary hormones
$D.$ Adrenal cortical hormones
Choose the correct answer from the options given below:

How do the signals from the parasympathetic nervous system affect the heart?

What is the effect of acetylcholine on the heart rate?

The heart's normal activities are regulated: