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.

Which neurotransmitter is released at the preganglionic sympathetic synapse?

• Serotonin

• Norepinephrine

• Acetylcholine

• Dopamine

What type of receptor does norepinephrine bind to in the heart?

• Muscarinic receptor

• Nicotinic receptor

• Beta adrenergic receptor

• Alpha adrenergic receptor

What is the effect of beta adrenergic receptor activation on cardiac output?

• Decreases heart rate

• Decreases cardiac output

• No effect on cardiac output

• Increases cardiac output

Which neurotransmitter is released at the postganglionic parasympathetic synapse?

• Norepinephrine

• Dopamine

• Acetylcholine

• Serotonin

What is the effect of muscarinic receptor activation on the heart?

• Increases heart rate

• Increases conduction velocity

• Increases contractility

• Decreases cardiac output