Final answer:
The parasympathetic branch of the ANS arises from the brainstem and lower regions of the spinal cord and has long pre-ganglionic fibers. It is responsible for 'rest and digest' activities, utilizing long preganglionic fibers and acetylcholine as a neurotransmitter.
Step-by-step explanation:
The correct options for the parasympathetic branch of the autonomic nervous system (ANS) are:
- c. Arises from the brainstem and lower regions of the spinal cord.
- d. Has long pre-ganglionic fibers.
The parasympathetic division, also known as the craniosacral outflow, consists of preganglionic neurons that are located in the brain stem and the lateral horn of the sacral spinal cord. These long preganglionic fibers project to terminal ganglia, which are either close to or within the target organs.
The parasympathetic system is responsible for the 'rest and digest' activities, such as slowing heart rate, lowering blood pressure, and stimulating digestion. Contrary to the sympathetic nervous system which has most of its preganglionic neurons originating in the spinal cord, the parasympathetic system's fibers arise from the brainstem and sacral spinal cord, and they release acetylcholine to induce their calming effects on the body.