Question

Define parasympathetic.

Option 1: Part of the autonomic nervous system with "rest and digest" function, decrease RR and HR, increase digestion
Option 2: Insulating lipid layer covering some neurons in the brain and spinal cord and most peripheral nerves
Option 3: A knotlike mass of neuron cell bodies located outside of the CNS
Option 4: Complete loss of neurologic function on the caudal half of the body

Answer 1

The parasympathetic nervous system is an autonomic nervous system division that manages the body's rest and digest processes, decreasing HR and RR, and enhancing digestion by regulating organ functions to conserve energy and maintain calm.

Step-by-step explanation:

The parasympathetic nervous system is part of the autonomic nervous system, which operates involuntarily to manage the body's internal environment. Specifically, the parasympathetic division is responsible for the "rest and digest" functions of the body. This system works in contrast to the sympathetic nervous system, which is responsible for the "fight or flight" response in stressful situations. When activated, the parasympathetic nervous system helps to decrease heart rate (HR) and respiratory rate (RR), lower blood pressure, and enhance digestion by stimulating gastrointestinal activity. Its role is to conserve energy and restore the body to a state of calm.

Preganglionic neurons of the parasympathetic system have their cell bodies in the brainstem and the sacral spinal cord, and they release acetylcholine onto postganglionic neurons, which in turn generally release acetylcholine or nitric oxide onto target organs, helping to promote relaxation and digestion. A mnemonic to remember its function is that both "parasympathetic" and "picnic" start with 'p,' recalling a peaceful restful scenario conducive to digestion.