Autonomic innervation of the heart

The video tutorial explains the roles of the sympathetic and parasympathetic nervous systems in regulating heart function. It details the neurotransmitters involved in pre- and postganglionic synapses and the receptors they bind to. The sympathetic system increases cardiac output by releasing norepinephrine, which binds to beta adrenergic receptors, enhancing heart rate and contractility. Conversely, the parasympathetic system decreases cardiac output by releasing acetylcholine, which binds to muscarinic receptors, reducing heart rate and contractility.

Explain the difference between nicotinic and muscarinic receptors in the context of the heart.

What is the effect of parasympathetic innervation on heart rate and cardiac output?